Clean up UI windows and strengthen settings workflows

.gitignore

@@ -3,4 +3,5 @@ __pycache__/
 *.py[cod]
 logs/
 model_settings.json
+link_settings.json
 runtime/

README.md

@@ -16,6 +16,7 @@ The script creates a virtual environment and installs dependencies automatically
 On first launch, it also adds a **SUB Control** desktop shortcut.
 Select a COM port and **Connect**, or choose **Demo Mode** to try it without hardware.
 Connection settings are under **•••**.
+Click **Data link** for an extended connection test, or **Console** to inspect RX/TX messages and pause the view.
 
 ## Controls
 

SUB Control/.gitignore

@@ -3,4 +3,5 @@ __pycache__/
 *.py[cod]
 logs/
 model_settings.json
+link_settings.json
 runtime/

SUB Control/README.md

@@ -16,6 +16,7 @@ The script creates a virtual environment and installs dependencies automatically
 On first launch, it also adds a **SUB Control** desktop shortcut.
 Select a COM port and **Connect**, or choose **Demo Mode** to try it without hardware.
 Connection settings are under **•••**.
+Click **Data link** for an extended connection test, or **Console** to inspect RX/TX messages and pause the view.
 
 ## Controls
 

SUB Control/app.py

@@ -13,6 +13,9 @@ from datetime import datetime
 from pathlib import Path
 from tkinter import messagebox, ttk
 
+# ESC_TELEMETRY_1_TO_4 uses a MAVLink 2 message ID. Select the v2 dialect
+# before importing pymavlink so received ESC packets can be decoded/logged.
+os.environ["MAVLINK20"] = "1"
 from pymavlink import mavutil
 from serial.tools import list_ports
 
@@ -67,6 +70,10 @@ class MavlinkWorker:
         self.connection = None
         self.stop_event = threading.Event()
         self.lock = threading.Lock()
+        # pymavlink writes are not thread-safe. The web/API thread can issue
+        # commands while this worker sends heartbeats and controls, so serialize
+        # every packet before it reaches a low-bandwidth serial link.
+        self.tx_lock = threading.Lock()
         self.thread = None
         self.axes = Axes()
         self.output_axes = Axes()
@@ -87,6 +94,34 @@ class MavlinkWorker:
         self.last_rx = 0.0
         self.armed = False
         self.config_paused = False
+        # Keep configuration traffic off the link during an arm/disarm
+        # transition, including the wait for the vehicle's confirmation.
+        self.command_quiet_until = 0.0
+        self.disarm_requested_until = 0.0
+        self.pending_arm_state = None
+        self.next_arm_retry_at = 0.0
+        self.arm_retry_deadline = 0.0
+        self.arm_confirmation = 0
+        self.stream_config = deque()
+        self.next_stream_config_at = 0.0
+        # Low-rate TIMESYNC echoes measure PC↔FC round trips with minimal traffic.
+        self.ping_rate_hz = 1
+        self.heavy_quality_test = None
+        self.heavy_pending_pings = {}
+        self.heavy_quality_latest = None
+        self.telemetry_rates_hz = {
+            "SYS_STATUS": 1, "SERVO_OUTPUT_RAW": 2,
+            "RC_CHANNELS": 2, "ESC_TELEMETRY_1_TO_4": 1,
+        }
+        self.ping_sequence = 0
+        self.next_ping_at = 0.0
+        self.pending_pings = {}
+        self.ping_results = deque(maxlen=300)
+        self.bad_frame_times = deque()
+        self.bad_frame_bytes = deque()
+        self.rx_sequence_by_source = {}
+        self.rx_delivery_results = deque(maxlen=1024)
+        self.next_quality_publish_at = 0.0
         self.param_scan = deque()
         self.param_waiting = None
         self.param_deadline = 0.0
@@ -96,6 +131,9 @@ class MavlinkWorker:
         self.log_lock = threading.Lock()
         self.log_file = None
         self.log_path = None
+        self.console_lines = deque(maxlen=500)
+        self.console_rx_lines = deque(maxlen=300)
+        self.console_tx_lines = deque(maxlen=300)
 
     def connect(self, port: str, baud: int):
         print(f"[MavlinkWorker] connect() called: port={port!r}, baud={baud}")
@@ -109,8 +147,12 @@ class MavlinkWorker:
         self.log_file = self.log_path.open("a", encoding="utf-8", buffering=1)
         normalized = normalize_endpoint(port)
         print(f"[MavlinkWorker] normalized endpoint: {normalized!r}")
-        self.log("SESSION", f"start port={normalized} (input={port}) baud={baud} control_hz={self.rate_hz}")
+        self.log("SESSION", f"start port={normalized} (input={port}) baud={baud} "
+                 f"control_hz={self.rate_hz} rx=MAVLink2 tx=MAVLink2")
         self.events.put(("log_path", str(self.log_path)))
+        self.last_heartbeat = 0.0
+        self.last_rx = 0.0
+        self.next_quality_publish_at = 0.0
         self.thread = threading.Thread(
             target=self._run, args=(normalized, baud), daemon=True
         )
@@ -137,7 +179,7 @@ class MavlinkWorker:
 
             # Send initial GCS heartbeat immediately
             self.log("TX_HEARTBEAT", "GCS initial")
-            conn.mav.heartbeat_send(
+            self._send_mav(conn, "heartbeat_send",
                 mavutil.mavlink.MAV_TYPE_GCS,
                 mavutil.mavlink.MAV_AUTOPILOT_INVALID,
                 0, 0, mavutil.mavlink.MAV_STATE_ACTIVE,
@@ -149,17 +191,32 @@ class MavlinkWorker:
                 now = time.monotonic()
                 if now >= next_gcs_hb:
                     self.log("TX_HEARTBEAT", "GCS")
-                    conn.mav.heartbeat_send(
+                    self._send_mav(conn, "heartbeat_send",
                         mavutil.mavlink.MAV_TYPE_GCS,
                         mavutil.mavlink.MAV_AUTOPILOT_INVALID,
                         0, 0, mavutil.mavlink.MAV_STATE_ACTIVE,
                     )
                     next_gcs_hb = now + 1.0
-                if self.target_system and now >= next_control:
+                # ArduSub cannot use MANUAL_CONTROL while disarmed. Keeping a
+                # 20 Hz neutral stream alive here only competes with ARM and
+                # its acknowledgement on constrained links.
+                if self.target_system and self.armed and now >= next_control:
                     self._send_control()
-                    next_control = now + (1.0 / max(1, self.rate_hz))
+                    # The first disarm packet is preceded by a neutral command.
+                    # Until disarm is confirmed, keep sending neutral at a
+                    # lower rate instead of consuming 20 Hz on the weak link.
+                    control_hz = min(self.rate_hz, 5) if now < self.disarm_requested_until else self.rate_hz
+                    next_control = now + (1.0 / max(1, control_hz))
+                elif not self.armed:
+                    next_control = now
                 if self.target_system:
+                    self._tick_arm_retry(now)
+                    self._tick_link_probe(now)
+                    self._tick_stream_config(now)
                     self._tick_param_scan(now)
+                if now >= self.next_quality_publish_at:
+                    self._publish_link_quality()
+                    self.next_quality_publish_at = now + 1.0
 
                 msg = conn.recv_match(blocking=False)
                 if msg:
@@ -170,6 +227,8 @@ class MavlinkWorker:
             print(f"[MavlinkWorker._run] EXCEPTION: {exc}")
             self.events.put(("error", f"Connection error: {exc}"))
         finally:
+            if self.heavy_quality_test is not None:
+                self.cancel_heavy_quality_test()
             self._safe_stop()
             if self.connection:
                 try:
@@ -180,6 +239,19 @@ class MavlinkWorker:
             self.target_system = 0
             self.armed = False
             self.config_paused = False
+            self.command_quiet_until = 0.0
+            self.disarm_requested_until = 0.0
+            self.pending_arm_state = None
+            self.next_arm_retry_at = 0.0
+            self.arm_retry_deadline = 0.0
+            self.arm_confirmation = 0
+            self.stream_config.clear()
+            self.pending_pings.clear()
+            self.ping_results.clear()
+            self.bad_frame_times.clear()
+            self.bad_frame_bytes.clear()
+            self.rx_sequence_by_source.clear()
+            self.rx_delivery_results.clear()
             self.log("SESSION", "disconnected")
             with self.log_lock:
                 if self.log_file:
@@ -189,22 +261,71 @@ class MavlinkWorker:
 
     def log(self, category: str, message: str):
         timestamp = datetime.now().astimezone().isoformat(timespec="milliseconds")
+        line = f"{timestamp} [{category}] {message}"
         with self.log_lock:
+            self.console_lines.append(line[:2000])
+            if category.startswith("RX") or category == "ONBOARD_LOG_ERROR":
+                self.console_rx_lines.append(line[:2000])
+            elif category.startswith("TX") or category == "OPERATOR":
+                self.console_tx_lines.append(line[:2000])
             if self.log_file:
-                self.log_file.write(f"{timestamp} [{category}] {message}\n")
+                self.log_file.write(line + "\n")
+
+    def read_console(self, limit=150):
+        with self.log_lock:
+            limit = max(1, min(300, int(limit)))
+            return {
+                "rx": list(self.console_rx_lines)[-limit:],
+                "tx": list(self.console_tx_lines)[-limit:],
+            }
+
+    def _send_mav(self, connection, method: str, *args):
+        """Serialize MAVLink 2 writes and protect the start of each burst."""
+        with self.tx_lock:
+            # This full-duplex module pair loses the opening bytes of some
+            # PC-to-FC bursts after the line has been idle. Put a valid,
+            # expendable GCS heartbeat first so the following packet remains
+            # intact and the FC also sees a healthy GCS heartbeat stream.
+            if method != "heartbeat_send" and hasattr(connection.mav, "heartbeat_send"):
+                connection.mav.heartbeat_send(
+                    mavutil.mavlink.MAV_TYPE_GCS,
+                    mavutil.mavlink.MAV_AUTOPILOT_INVALID,
+                    0, 0, mavutil.mavlink.MAV_STATE_ACTIVE,
+                )
+            getattr(connection.mav, method)(*args)
 
     def _handle_message(self, msg):
         msg_type = msg.get_type()
         if msg_type == "BAD_DATA":
+            now = time.monotonic()
+            self.bad_frame_times.append(now)
+            self.bad_frame_bytes.append((now, len(getattr(msg, "data", b""))))
+            self._trim_bad_frames(now)
             self.log("RX_BAD_DATA", repr(getattr(msg, "data", b"")))
             return
         self.last_rx = time.monotonic()
+        self._track_rx_delivery(msg)
         try:
             payload = json.dumps(msg.to_dict(), default=str, separators=(",", ":"))
         except Exception:
             payload = str(msg)
         self.log("RX", payload)
-        if msg_type == "HEARTBEAT" and getattr(msg, "type", 0) != mavutil.mavlink.MAV_TYPE_GCS:
+        if msg_type == "TIMESYNC" and int(getattr(msg, "tc1", 0)) != 0:
+            token = int(getattr(msg, "ts1", -1))
+            heavy_probe = self.heavy_pending_pings.pop(token, None)
+            if heavy_probe is not None:
+                stage_index, sent_at = heavy_probe
+                self._record_heavy_probe(stage_index, (time.monotonic() - sent_at) * 1000.0)
+                self._publish_heavy_quality()
+                sent_at = None
+            else:
+                sent_at = self.pending_pings.pop(token, None)
+            if sent_at is not None:
+                rtt_ms = (time.monotonic() - sent_at) * 1000.0
+                self.ping_results.append((time.monotonic(), rtt_ms))
+                self.log("RX_LINK_PROBE", f"timesync={token} rtt_ms={rtt_ms:.1f}")
+                self._publish_link_quality()
+        elif msg_type == "HEARTBEAT" and getattr(msg, "type", 0) != mavutil.mavlink.MAV_TYPE_GCS:
             if getattr(msg, "autopilot", mavutil.mavlink.MAV_AUTOPILOT_INVALID) == mavutil.mavlink.MAV_AUTOPILOT_INVALID:
                 return
             if self.target_system and (msg.get_srcSystem(), msg.get_srcComponent()) != (self.target_system, self.target_component):
@@ -216,6 +337,10 @@ class MavlinkWorker:
             armed = bool(msg.base_mode & mavutil.mavlink.MAV_MODE_FLAG_SAFETY_ARMED)
             self.armed = armed
             self.config_paused = armed
+            if self.pending_arm_state is not None and armed == self.pending_arm_state:
+                self.pending_arm_state = None
+            if not armed:
+                self.disarm_requested_until = 0.0
             try:
                 mode = mavutil.mode_string_v10(msg)
             except Exception:
@@ -224,6 +349,7 @@ class MavlinkWorker:
             ap_name = autopilot.name if autopilot else str(msg.autopilot)
             self.events.put(("heartbeat", self.target_system, ap_name, mode, armed, self.last_heartbeat))
             if first:
+                self.next_ping_at = time.monotonic()
                 self.events.put(("status", "Heartbeat received; controls are neutral."))
                 self._configure_low_bandwidth_streams()
                 self._start_servo_scan()
@@ -232,12 +358,21 @@ class MavlinkWorker:
                 return
             result = mavutil.mavlink.enums["MAV_RESULT"].get(msg.result)
             result_name = result.name if result else str(msg.result)
+            if int(msg.command) == mavutil.mavlink.MAV_CMD_SET_MESSAGE_INTERVAL:
+                self.log("RX_STREAM_CONFIG_ACK", result_name)
+                return
+            if (int(msg.command) == mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM
+                    and result_name not in ("MAV_RESULT_ACCEPTED", "MAV_RESULT_IN_PROGRESS")):
+                self.pending_arm_state = None
             self.events.put(("ack", int(msg.command), result_name, self.last_rx))
         elif msg_type == "STATUSTEXT":
             text = msg.text
             if isinstance(text, bytes):
                 text = text.decode(errors="replace")
-            self.events.put(("statustext", text.rstrip("\x00")))
+            text = text.rstrip("\x00")
+            if "/APM/LOGS" in text and "Failed" in text:
+                self.log("ONBOARD_LOG_ERROR", text)
+            self.events.put(("statustext", text))
         elif msg_type == "SYS_STATUS":
             voltage_mv = int(msg.voltage_battery)
             if 0 < voltage_mv < 65535:
@@ -264,6 +399,238 @@ class MavlinkWorker:
                     self.events.put(("motor_direction", int(parts[1]),
                                      int(round(msg.param_value))))
 
+    def _trim_bad_frames(self, now):
+        while self.bad_frame_times and now - self.bad_frame_times[0] > 20.0:
+            self.bad_frame_times.popleft()
+
+    def _track_rx_delivery(self, msg):
+        """Estimate downlink loss from MAVLink's per-source packet sequence."""
+        try:
+            source = (int(msg.get_srcSystem()), int(msg.get_srcComponent()))
+            sequence = int(msg.get_seq())
+        except (AttributeError, TypeError, ValueError):
+            return
+        if self.target_system and source != (self.target_system, self.target_component):
+            return
+        previous = self.rx_sequence_by_source.get(source)
+        self.rx_sequence_by_source[source] = sequence
+        if previous is None:
+            return
+        missing = (sequence - previous - 1) & 0xFF
+        # A large backwards jump is a reset/reordered packet, not 200 losses.
+        if missing > 127:
+            return
+        timestamp = time.monotonic()
+        self.rx_delivery_results.extend((timestamp, False) for _ in range(missing))
+        self.rx_delivery_results.append((timestamp, True))
+
+    def _publish_link_quality(self):
+        now = time.monotonic()
+        self._trim_bad_frames(now)
+        while self.ping_results and now - self.ping_results[0][0] > 30.0:
+            self.ping_results.popleft()
+        while self.rx_delivery_results and now - self.rx_delivery_results[0][0] > 30.0:
+            self.rx_delivery_results.popleft()
+        while self.bad_frame_bytes and now - self.bad_frame_bytes[0][0] > 20.0:
+            self.bad_frame_bytes.popleft()
+        samples = [sample for _, sample in self.ping_results]
+        received = [sample for sample in samples if sample is not None]
+        total = len(samples)
+        loss_percent = 100.0 * (total - len(received)) / total if total else None
+        ordered_rtt = sorted(received)
+        latency_ms = (sum(ordered_rtt) / len(ordered_rtt)) if ordered_rtt else None
+        median_rtt_ms = ordered_rtt[len(ordered_rtt) // 2] if ordered_rtt else None
+        p95_rtt_ms = ordered_rtt[min(len(ordered_rtt) - 1, (len(ordered_rtt) * 95 + 99) // 100 - 1)] if ordered_rtt else None
+        rx_received = sum(1 for _, delivered in self.rx_delivery_results if delivered)
+        rx_missing = sum(1 for _, delivered in self.rx_delivery_results if not delivered)
+        rx_loss_percent = 100.0 * rx_missing / (rx_received + rx_missing) if rx_received else None
+        rx_corrupt_bytes = sum(byte_count for _, byte_count in self.bad_frame_bytes)
+        heartbeat_age = (now - self.last_heartbeat) if self.last_heartbeat else None
+        if total < 10 or rx_received < 10 or heartbeat_age is None:
+            grade = "testing"
+        elif (heartbeat_age > 3 or loss_percent > 15
+              or (rx_loss_percent is not None and rx_loss_percent > 5)
+              or len(self.bad_frame_bytes) >= 5):
+            grade = "poor"
+        elif (loss_percent > 3 or (rx_loss_percent is not None and rx_loss_percent > 1)
+              or (p95_rtt_ms is not None and p95_rtt_ms > 500) or self.bad_frame_bytes):
+            grade = "fair"
+        elif (loss_percent > 0.5 or (rx_loss_percent is not None and rx_loss_percent > 0.2)
+              or (p95_rtt_ms is not None and p95_rtt_ms > 200)):
+            grade = "good"
+        else:
+            grade = "excellent"
+        self.events.put(("link_quality", {
+            "grade": grade,
+            "latency_ms": round(latency_ms, 1) if latency_ms is not None else None,
+            "rtt_median_ms": round(median_rtt_ms, 1) if median_rtt_ms is not None else None,
+            "rtt_p95_ms": round(p95_rtt_ms, 1) if p95_rtt_ms is not None else None,
+            "loss_percent": round(loss_percent, 1) if loss_percent is not None else None,
+            "probe_loss_percent": round(loss_percent, 1) if loss_percent is not None else None,
+            "probe_samples": total,
+            "probe_replies": len(received),
+            "rx_packets_30s": rx_received,
+            "rx_sequence_loss_percent": round(rx_loss_percent, 1) if rx_loss_percent is not None else None,
+            "rx_corrupt_frames_20s": len(self.bad_frame_bytes),
+            "rx_corrupt_bytes_20s": rx_corrupt_bytes,
+            "samples": total,
+            "corrupt_frames_20s": len(self.bad_frame_times),
+            "heartbeat_age_s": round(heartbeat_age, 1) if heartbeat_age is not None else None,
+            "probe_supported": total > 0,
+        }))
+
+    def _tick_link_probe(self, now):
+        if self.heavy_quality_test is not None:
+            self._tick_heavy_quality(now)
+            return
+        expired = [sequence for sequence, sent_at in self.pending_pings.items()
+                   if now - sent_at >= 2.5]
+        for sequence in expired:
+            self.pending_pings.pop(sequence, None)
+            self.ping_results.append((now, None))
+            self.log("LINK_PROBE_TIMEOUT", f"timesync={sequence}")
+        if expired:
+            self._publish_link_quality()
+        if (now < self.next_ping_at or now < self.command_quiet_until
+                or not self.connection or not self.target_system):
+            return
+        token = time.monotonic_ns()
+        self.pending_pings[token] = now
+        self.log("TX_LINK_PROBE", f"timesync={token}")
+        # ArduPilot implements TIMESYNC even on builds that omit PING. A
+        # request has tc1=0; the response mirrors our unique ts1 token.
+        self._send_mav(self.connection, "timesync_send", 0, token)
+        self.next_ping_at = now + (1.0 / max(1, self.ping_rate_hz))
+
+    def start_heavy_quality_test(self):
+        if not self.connection or not self.target_system:
+            raise RuntimeError("Connect to the flight controller before testing the link")
+        if self.armed:
+            raise RuntimeError("The heavy link test is available while the vehicle is disarmed")
+        if self.pending_arm_state is not None or time.monotonic() < self.command_quiet_until:
+            raise RuntimeError("Wait for the current vehicle command to finish")
+        if self.heavy_quality_test is not None:
+            raise RuntimeError("A heavy link test is already running")
+        self.pending_pings.clear()
+        self.heavy_pending_pings.clear()
+        self.heavy_quality_latest = {
+            "running": True, "stage": 1, "stages": 3, "rate_hz": 1,
+            "status": "Running", "results": [],
+        }
+        self.heavy_quality_test = {
+            "rates": (1, 5, 10), "duration_s": 10.0, "stage_index": 0,
+            "stage_started": time.monotonic(), "next_probe_at": time.monotonic(),
+            "stages": [{"rate_hz": rate, "sent": 0, "replies": 0,
+                        "timeouts": 0, "rtts": []} for rate in (1, 5, 10)],
+        }
+        self.log("TX_HEAVY_TEST", "started rates=1,5,10Hz stage_seconds=10")
+        self._publish_heavy_quality()
+        return self.heavy_quality_latest
+
+    def cancel_heavy_quality_test(self):
+        if self.heavy_quality_test is None:
+            return self.heavy_quality_latest
+        self.heavy_pending_pings.clear()
+        test = self.heavy_quality_test
+        self.heavy_quality_test = None
+        self.heavy_quality_latest = {
+            "running": False, "stage": 0, "stages": len(test["rates"]),
+            "rate_hz": None, "status": "Cancelled", "results": self._heavy_results(test),
+        }
+        self.next_ping_at = time.monotonic()
+        self.log("TX_HEAVY_TEST", "cancelled")
+        self.events.put(("heavy_quality", self.heavy_quality_latest))
+        return self.heavy_quality_latest
+
+    @staticmethod
+    def _heavy_results(test):
+        results = []
+        for stage in test["stages"]:
+            rtts = sorted(stage["rtts"])
+            replies = stage["replies"]
+            resolved = replies + stage["timeouts"]
+            results.append({
+                "rate_hz": stage["rate_hz"], "sent": stage["sent"], "replies": replies,
+                "loss_percent": round(100.0 * stage["timeouts"] / resolved, 1) if resolved else None,
+                "median_rtt_ms": round(rtts[len(rtts) // 2], 1) if rtts else None,
+                "p95_rtt_ms": round(rtts[min(len(rtts) - 1, (len(rtts) * 95 + 99) // 100 - 1)], 1) if rtts else None,
+            })
+        return results
+
+    def _record_heavy_probe(self, stage_index, rtt_ms=None):
+        test = self.heavy_quality_test
+        if test is None or not 0 <= stage_index < len(test["stages"]):
+            return
+        stage = test["stages"][stage_index]
+        if rtt_ms is None:
+            stage["timeouts"] += 1
+        else:
+            stage["replies"] += 1
+            stage["rtts"].append(rtt_ms)
+
+    def _publish_heavy_quality(self):
+        test = self.heavy_quality_test
+        if test is None:
+            return
+        index = test["stage_index"]
+        stage = test["stages"][index]
+        self.heavy_quality_latest = {
+            "running": True, "stage": index + 1, "stages": len(test["rates"]),
+            "rate_hz": stage["rate_hz"], "sent": stage["sent"],
+            "replies": stage["replies"], "timeouts": stage["timeouts"],
+            "status": f"Stage {index + 1} of {len(test['rates'])}: {stage['rate_hz']} Hz",
+            "results": self._heavy_results(test),
+        }
+        self.events.put(("heavy_quality", self.heavy_quality_latest))
+
+    def _tick_heavy_quality(self, now):
+        test = self.heavy_quality_test
+        if test is None:
+            return
+        for token, (stage_index, sent_at) in list(self.heavy_pending_pings.items()):
+            if now - sent_at >= 2.5:
+                self.heavy_pending_pings.pop(token, None)
+                self._record_heavy_probe(stage_index)
+                self.log("HEAVY_PROBE_TIMEOUT", f"rate={test['rates'][stage_index]}Hz timesync={token}")
+        index = test["stage_index"]
+        stage_pending = any(stage_index == index for stage_index, _ in self.heavy_pending_pings.values())
+        if now - test["stage_started"] >= test["duration_s"] and not stage_pending:
+            index += 1
+            if index >= len(test["rates"]):
+                results = self._heavy_results(test)
+                self.heavy_quality_test = None
+                self.heavy_quality_latest = {
+                    "running": False, "stage": 3, "stages": 3, "rate_hz": None,
+                    "status": "Complete", "results": results,
+                }
+                self.next_ping_at = now
+                self.log("TX_HEAVY_TEST", "complete")
+                self.events.put(("heavy_quality", self.heavy_quality_latest))
+                return
+            test["stage_index"] = index
+            test["stage_started"] = now
+            test["next_probe_at"] = now
+            self._publish_heavy_quality()
+        index = test["stage_index"]
+        stage = test["stages"][index]
+        if now >= test["next_probe_at"] and now - test["stage_started"] < test["duration_s"]:
+            token = time.monotonic_ns()
+            self.heavy_pending_pings[token] = (index, now)
+            stage["sent"] += 1
+            self.log("TX_HEAVY_PROBE", f"rate={stage['rate_hz']}Hz timesync={token}")
+            self._send_mav(self.connection, "timesync_send", 0, token)
+            test["next_probe_at"] = now + 1.0 / stage["rate_hz"]
+        if now >= self.next_quality_publish_at:
+            self._publish_heavy_quality()
+            self.next_quality_publish_at = now + 1.0
+
+    def set_link_rates(self, ping_hz, telemetry_rates):
+        self.ping_rate_hz = max(1, min(10, int(ping_hz)))
+        for name in self.telemetry_rates_hz:
+            if name in telemetry_rates:
+                self.telemetry_rates_hz[name] = max(0, min(10, int(telemetry_rates[name])))
+        if self.connection and self.target_system:
+            self._configure_low_bandwidth_streams()
     def _start_servo_scan(self):
         names = [f"SERVO{number}_FUNCTION" for number in range(1, 17)]
         # ArduSub reverses mixer motors with MOT_n_DIRECTION (1 normal,
@@ -284,31 +651,52 @@ class MavlinkWorker:
         self.param_retries = 0
 
     def _configure_low_bandwidth_streams(self):
-        """Stop inherited high-rate streams and request only diagnostic essentials."""
+        """Pace optional telemetry changes; never burst them at arm time."""
         if not self.connection:
             return
         self.log("TX_STREAM_CONFIG", "stop MAV_DATA_STREAM_ALL")
-        self.connection.mav.request_data_stream_send(
+        self._send_mav(self.connection, "request_data_stream_send",
             self.target_system, self.target_component,
             mavutil.mavlink.MAV_DATA_STREAM_ALL, 0, 0,
         )
-        # Heartbeat and STATUSTEXT do not need to be requested. Keep only
+        # ATTITUDE and VFR_HUD interval commands were accepted by this FC.
-        # output/input evidence needed to diagnose controls, at 2 Hz each.
+        # AHRS2 is also unneeded, but an acknowledgement has not been seen.
-        for message_id, interval_us, name in (
+        # NAMED_VALUE_FLOAT explicitly returned DENIED, so do not retry it.
-            (mavutil.mavlink.MAVLINK_MSG_ID_SYS_STATUS, 1_000_000, "SYS_STATUS"),
+        # A single interval command is sometimes lost, so send two paced
-            (mavutil.mavlink.MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, 500_000, "SERVO_OUTPUT_RAW"),
+        # passes. This does not change persistent parameters or onboard logs.
-            (mavutil.mavlink.MAVLINK_MSG_ID_RC_CHANNELS, 500_000, "RC_CHANNELS"),
+        unwanted = (
-        ):
+            "ATTITUDE", "AHRS2", "VFR_HUD",
-            self.log("TX_STREAM_CONFIG", f"{name} interval_us={interval_us}")
+        )
-            self.connection.mav.command_long_send(
+        self.stream_config = deque(
-                self.target_system, self.target_component,
+            (name, getattr(mavutil.mavlink, f"MAVLINK_MSG_ID_{name}"), -1)
-                mavutil.mavlink.MAV_CMD_SET_MESSAGE_INTERVAL,
+            for _ in range(2) for name in unwanted
-                0, message_id, interval_us, 0, 0, 0, 0, 0,
+        )
-            )
+        for name, rate_hz in self.telemetry_rates_hz.items():
-        self.events.put(("status", "Low-bandwidth telemetry configured; reading servo setup…"))
+            interval_us = -1 if rate_hz == 0 else round(1_000_000 / rate_hz)
+            self.stream_config.append((
+                name, getattr(mavutil.mavlink, f"MAVLINK_MSG_ID_{name}"), interval_us,
+            ))
+        self.next_stream_config_at = time.monotonic()
+        self.events.put(("status", "Applying low-bandwidth telemetry rates…"))
+
+    def _tick_stream_config(self, now):
+        if (not self.connection or not self.target_system or self.armed
+                or now < self.command_quiet_until or now < self.next_stream_config_at
+                or not self.stream_config):
+            return
+        name, message_id, interval_us = self.stream_config.popleft()
+        self.log("TX_STREAM_CONFIG", f"{name} interval_us={interval_us}")
+        self._send_mav(self.connection, "command_long_send",
+            self.target_system, self.target_component,
+            mavutil.mavlink.MAV_CMD_SET_MESSAGE_INTERVAL,
+            0, message_id, interval_us, 0, 0, 0, 0, 0,
+        )
+        self.next_stream_config_at = now + 0.5
 
     def _tick_param_scan(self, now):
-        if not self.connection or self.config_paused or now < self.param_deadline:
+        if (not self.connection or self.config_paused
+                or self.stream_config or now < self.next_stream_config_at
+                or now < self.command_quiet_until or now < self.param_deadline):
             return
         if self.param_waiting is not None:
             if self.param_retries < 2:
@@ -329,7 +717,7 @@ class MavlinkWorker:
 
     def _request_param(self, name: str):
         self.log("TX_PARAM_REQUEST", name)
-        self.connection.mav.param_request_read_send(
+        self._send_mav(self.connection, "param_request_read_send",
             self.target_system, self.target_component, name.encode("ascii"), -1
         )
 
@@ -343,7 +731,7 @@ class MavlinkWorker:
             raise RuntimeError(f"{name} has not been read from the autopilot")
         self.pending_sets[name] = int(value)
         self.log("TX_PARAM_SET", f"{name}={value} type={param_type}")
-        self.connection.mav.param_set_send(
+        self._send_mav(self.connection, "param_set_send",
             self.target_system, self.target_component, name.encode("ascii"),
             float(value), param_type,
         )
@@ -396,7 +784,7 @@ class MavlinkWorker:
             f"x={x} y={y} z={z} r={r} active={active} "
             f"target=({target.forward:.3f},{target.lateral:.3f},{target.vertical:.3f},{target.yaw:.3f})",
         )
-        conn.mav.manual_control_send(self.target_system, x, y, z, r, 0)
+        self._send_mav(conn, "manual_control_send", self.target_system, x, y, z, r, 0)
 
     @staticmethod
     def _approach(current: float, target: float, max_change: float) -> float:
@@ -409,18 +797,45 @@ class MavlinkWorker:
         conn = self.connection
         if not conn or not self.target_system:
             raise RuntimeError("No autopilot heartbeat")
+        if arm and self.heavy_quality_test is not None:
+            self.cancel_heavy_quality_test()
+        now = time.monotonic()
+        self.command_quiet_until = now + 6.0
         if not arm:
+            self.disarm_requested_until = now + 6.0
             self._send_control(force_neutral=True)
         else:
             # Give the ARM request priority over the low-rate parameter scan.
             self.config_paused = True
         self.log("TX_COMMAND", "ARM" if arm else "DISARM")
-        conn.mav.command_long_send(
+        self.pending_arm_state = bool(arm)
+        self.next_arm_retry_at = now + 0.25
+        self.arm_retry_deadline = now + 5.0
+        self.arm_confirmation = 0
+        self._send_arm_packet(arm)
+
+    def _send_arm_packet(self, arm: bool):
+        conn = self.connection
+        if not conn or not self.target_system:
+            return
+        self._send_mav(conn, "command_long_send",
             self.target_system, self.target_component,
             mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
-            0, 1.0 if arm else 0.0, 0, 0, 0, 0, 0, 0,
+            self.arm_confirmation, 1.0 if arm else 0.0, 0, 0, 0, 0, 0, 0,
         )
 
+    def _tick_arm_retry(self, now):
+        if self.pending_arm_state is None or now < self.next_arm_retry_at:
+            return
+        if now >= self.arm_retry_deadline:
+            self.log("TX_COMMAND_TIMEOUT", "ARM" if self.pending_arm_state else "DISARM")
+            self.pending_arm_state = None
+            return
+        self.log("TX_COMMAND_RETRY", "ARM" if self.pending_arm_state else "DISARM")
+        self.arm_confirmation = min(255, self.arm_confirmation + 1)
+        self._send_arm_packet(self.pending_arm_state)
+        self.next_arm_retry_at = now + 0.25
+
     def set_manual_mode(self):
         conn = self.connection
         if not conn or not self.target_system:
@@ -430,7 +845,7 @@ class MavlinkWorker:
         if manual is None:
             raise RuntimeError("MANUAL mode is not advertised by this firmware")
         self.log("TX_MODE", f"MANUAL custom_mode={manual}")
-        conn.mav.set_mode_send(
+        self._send_mav(conn, "set_mode_send",
             self.target_system,
             mavutil.mavlink.MAV_MODE_FLAG_CUSTOM_MODE_ENABLED,
             manual,
@@ -467,7 +882,7 @@ class MavlinkWorker:
         if self.connection and self.target_system:
             try:
                 self._send_control(force_neutral=True)
-                self.connection.mav.command_long_send(
+                self._send_mav(self.connection, "command_long_send",
                     self.target_system, self.target_component,
                     mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
                     0, 0, 0, 0, 0, 0, 0, 0,

SUB Control/tests/test_vehicle_state.py

@@ -1,6 +1,9 @@
 """No serial port is opened by these tests."""
 import queue
+import threading
+import time
 import unittest
+from types import SimpleNamespace
 from unittest.mock import Mock, patch
 
 from app import Axes, MavlinkWorker, NEUTRAL_Z
@@ -100,9 +103,18 @@ class WorkerWatchdogTests(unittest.TestCase):
 
     def assertNeutral(self):
         self.worker._send_control()
-        self.assertEqual(self.worker.connection.mav.manual_control_send.call_args.args,
+        self.assertEqual(self.control_values(),
                          (1, 0, 0, NEUTRAL_Z, 0, 0))
 
+    def control_values(self):
+        return self.worker.connection.mav.manual_control_send.call_args.args
+
+    def test_manual_control_uses_native_v2_without_forced_long_payload(self):
+        self.worker._send_mav(self.worker.connection, 'manual_control_send',
+                              1, 50, 0, 525, -20, 0)
+        self.assertEqual(self.control_values(), (1, 50, 0, 525, -20, 0))
+        self.assertEqual(self.worker.connection.mav.manual_control_send.call_args.kwargs, {})
+
     def test_ui_freeze_neutralizes_and_does_not_replay(self):
         with patch("app.time.monotonic", return_value=10):
             self.worker.set_axes(Axes(forward=1), 1)
@@ -118,7 +130,7 @@ class WorkerWatchdogTests(unittest.TestCase):
             self.worker.set_axes(Axes(forward=.25, vertical=.25), 1)
             self.worker._send_control()
             # 25% input at the default 20% limit: 5% command, not 100%.
-            self.assertEqual(self.worker.connection.mav.manual_control_send.call_args.args,
+            self.assertEqual(self.control_values(),
                              (1, 50, 0, 525, 0, 0))
 
     def test_heartbeat_freeze_neutralizes_even_with_live_ui(self):
@@ -131,6 +143,160 @@ class WorkerWatchdogTests(unittest.TestCase):
         self.worker.set_axes(Axes(forward=1), 19)
         self.assertEqual(self.worker.axes, Axes())
 
+    def test_mavlink_transmissions_are_serialized(self):
+        first_entered = threading.Event()
+        release_first = threading.Event()
+        second_entered = threading.Event()
+
+        class Mav:
+            def first_send(self, **_):
+                first_entered.set()
+                release_first.wait(1)
+
+            def second_send(self, **_):
+                second_entered.set()
+
+        connection = SimpleNamespace(mav=Mav())
+        first = threading.Thread(target=self.worker._send_mav,
+                                 args=(connection, "first_send"))
+        second = threading.Thread(target=self.worker._send_mav,
+                                  args=(connection, "second_send"))
+        first.start()
+        self.assertTrue(first_entered.wait(.5))
+        second.start()
+        time.sleep(.05)
+        self.assertFalse(second_entered.is_set())
+        release_first.set()
+        first.join(1)
+        second.join(1)
+        self.assertTrue(second_entered.is_set())
+
+    def test_live_console_is_read_only_bounded_and_keeps_newest_lines(self):
+        for index in range(310):
+            self.worker.log("RX_TEST", f"vehicle {index}")
+            self.worker.log("TX_TEST", f"computer {index}")
+        sides = self.worker.read_console(2)
+        self.assertEqual(set(sides), {"rx", "tx"})
+        self.assertTrue(sides["rx"][0].endswith("[RX_TEST] vehicle 308"))
+        self.assertTrue(sides["rx"][1].endswith("[RX_TEST] vehicle 309"))
+        self.assertTrue(sides["tx"][1].endswith("[TX_TEST] computer 309"))
+        self.assertEqual(len(self.worker.console_rx_lines), 300)
+        self.assertEqual(len(self.worker.console_tx_lines), 300)
+        self.assertEqual(len(self.worker.console_lines), 500)
+
+    def test_arm_request_pauses_parameter_traffic(self):
+        self.worker.armed = False
+        self.worker.param_scan.append("SERVO1_FUNCTION")
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.command_arm(True)
+            self.worker.config_paused = False  # A disarmed heartbeat arrived.
+            self.worker._tick_param_scan(10.1)
+        self.assertEqual(self.worker.command_quiet_until, 16)
+        self.worker.connection.mav.param_request_read_send.assert_not_called()
+        self.worker.connection.mav.command_long_send.assert_called_once()
+
+    def test_arm_request_retries_until_state_confirmation(self):
+        self.worker.armed = False
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.command_arm(True)
+        self.worker._tick_arm_retry(10.24)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker._tick_arm_retry(10.25)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 2)
+        self.worker.pending_arm_state = None
+        self.worker._tick_arm_retry(10.50)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 2)
+
+    def test_outbound_command_has_valid_heartbeat_lead_in(self):
+        self.worker._send_mav(self.worker.connection, "timesync_send", 0, 123)
+        names = [call[0] for call in self.worker.connection.mav.method_calls]
+        self.assertEqual(names[-2:], ["heartbeat_send", "timesync_send"])
+
+    def test_disarm_sends_neutral_and_pauses_parameter_traffic(self):
+        self.worker.param_scan.append("SERVO1_FUNCTION")
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.command_arm(False)
+            self.worker.config_paused = False
+            self.worker._tick_param_scan(10.1)
+        self.assertEqual(self.worker.disarm_requested_until, 16)
+        self.assertEqual(self.control_values(),
+                         (1, 0, 0, NEUTRAL_Z, 0, 0))
+        self.worker.connection.mav.param_request_read_send.assert_not_called()
+
+    def test_telemetry_config_is_paced_and_includes_low_rate_esc(self):
+        self.worker.armed = False
+        with patch("app.time.monotonic", return_value=10):
+            self.worker._configure_low_bandwidth_streams()
+        self.assertEqual(len(self.worker.stream_config), 10)
+        self.assertEqual(self.worker.stream_config[-1][0], "ESC_TELEMETRY_1_TO_4")
+        self.assertEqual(self.worker.stream_config[-1][2], 1_000_000)
+        self.worker.connection.mav.command_long_send.assert_not_called()
+        self.worker._tick_stream_config(10)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker._tick_stream_config(10.1)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker.command_quiet_until = 16
+        self.worker._tick_stream_config(11)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker._tick_stream_config(16)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 2)
+
+    def test_link_probe_uses_configured_rate_and_measures_exact_echo(self):
+        self.worker.armed = False
+        self.worker.ping_rate_hz = 5
+        with patch("app.time.monotonic", return_value=10), \
+             patch("app.time.monotonic_ns", return_value=10_000_000_000):
+            self.worker._tick_link_probe(10)
+        self.worker.connection.mav.timesync_send.assert_called_once_with(
+            0, 10_000_000_000)
+        self.assertEqual(self.worker.pending_pings, {10_000_000_000: 10})
+        self.assertEqual(self.worker.next_ping_at, 10.2)
+        message = SimpleNamespace(
+            tc1=1, ts1=10_000_000_000, get_type=lambda: "TIMESYNC",
+            to_dict=lambda: {"tc1": 1, "ts1": 10_000_000_000})
+        with patch("app.time.monotonic", return_value=10.04):
+            self.worker._handle_message(message)
+        quality = self.worker.events.get_nowait()
+        self.assertEqual(quality[0], "link_quality")
+        self.assertEqual(quality[1]["latency_ms"], 40.0)
+        self.assertEqual(quality[1]["loss_percent"], 0.0)
+
+    def test_link_rates_rebuild_requested_telemetry_intervals(self):
+        self.worker.armed = False
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.set_link_rates(10, {
+                "SYS_STATUS": 5, "SERVO_OUTPUT_RAW": 10,
+                "RC_CHANNELS": 0, "ESC_TELEMETRY_1_TO_4": 2,
+            })
+        self.assertEqual(self.worker.ping_rate_hz, 10)
+        configured = {name: interval for name, _, interval in self.worker.stream_config}
+        self.assertEqual(configured["SYS_STATUS"], 200_000)
+        self.assertEqual(configured["SERVO_OUTPUT_RAW"], 100_000)
+        self.assertEqual(configured["RC_CHANNELS"], -1)
+        self.assertEqual(configured["ESC_TELEMETRY_1_TO_4"], 500_000)
+
+    def test_link_probe_counts_timeout_and_pauses_for_commands(self):
+        self.worker.pending_pings[4] = 5
+        self.worker.rx_delivery_results.extend(((10, True), (10, False)))
+        self.worker.next_ping_at = 0
+        self.worker.command_quiet_until = 20
+        with patch("app.time.monotonic", return_value=10):
+            self.worker._tick_link_probe(10)
+        self.worker.connection.mav.timesync_send.assert_not_called()
+        self.assertEqual(list(self.worker.ping_results), [(10, None)])
+        quality = self.worker.events.get_nowait()[1]
+        self.assertEqual(quality["loss_percent"], 100.0)
+        self.assertEqual(quality["grade"], "testing")
+
+    def test_clean_downlink_cannot_hide_failed_round_trips(self):
+        self.worker.ping_results.extend([(10, None)] * 20)
+        self.worker.rx_delivery_results.extend([(10, True)] * 200)
+        with patch("app.time.monotonic", return_value=10):
+            self.worker._publish_link_quality()
+        quality = self.worker.events.get_nowait()[1]
+        self.assertEqual(quality["loss_percent"], 100.0)
+        self.assertEqual(quality["grade"], "poor")
+
 
 class BridgeTests(unittest.TestCase):
     def test_delayed_arm_after_focus_reset_or_expiry_is_not_sent(self):

SUB Control/tests/ui_windows.cjs

@@ -0,0 +1,140 @@
+/* Browser regression check. Run: node tests/ui_windows.cjs [path-to-playwright]
+   Uses a simulated Python bridge; never opens a COM port or sends MAVLink. */
+const assert=require('node:assert/strict');
+const fs=require('node:fs');
+const path=require('node:path');
+const http=require('node:http');
+const {chromium}=require(process.argv[2]||'playwright');
+const root=path.resolve(__dirname,'..'),output=path.join(root,'runtime','ui-check');
+fs.mkdirSync(output,{recursive:true});
+const server=http.createServer((req,res)=>{
+  const url=decodeURIComponent(new URL(req.url,'http://localhost').pathname);
+  let file=path.resolve(root,'.'+url);
+  if(url==='/model.stl'||url==='/model')file=path.join(root,'runtime','vehicle_model.stl');
+  if(!file.startsWith(root+path.sep)||!fs.existsSync(file)||!fs.statSync(file).isFile()){
+    res.writeHead(404);res.end();return;
+  }
+  const types={'.html':'text/html','.js':'text/javascript','.css':'text/css','.stl':'model/stl'};
+  res.setHeader('Content-Type',types[path.extname(file)]||'application/octet-stream');
+  fs.createReadStream(file).pipe(res);
+});
+async function main(){
+  await new Promise(resolve=>server.listen(0,'127.0.0.1',resolve));
+  const browser=await chromium.launch({headless:true});
+  try{
+    const page=await browser.newPage({viewport:{width:1080,height:720}});
+    const errors=[];page.on('pageerror',error=>errors.push(error.message));
+    await page.addInitScript(()=>{
+      const clone=value=>JSON.parse(JSON.stringify(value));
+      const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,motor:i<=3?i:null,direction:i<=3?1:null};
+      const state={connected:false,armed:false,armed_known:false,mode:null,app_state:'disconnected',status:'Ready',servos,link_quality:null};
+      const battery={cells:4,capacity_mah:5500,c_rating:35,full_v_per_cell:4.2,empty_v_per_cell:3.3,warning_percent:20};
+      const link={baud:57600,control_hz:20,ping_hz:1,system_hz:1,servo_hz:2,rc_hz:2,esc_hz:1};
+      const calls={battery:0,link:0,heavy:0,reverse:0,console:0,connect:[]};
+      const sleep=ms=>new Promise(resolve=>setTimeout(resolve,ms));
+      window.testBridge={state,battery,link,calls,failBattery:false,failMotor:false};
+      window.pywebview={api:{
+        initial_state:async()=>({ports:[{device:'COM5',label:'COM5'}],state:clone(state),battery_config:clone(battery),link_config:clone(link)}),
+        refresh_ports:async()=>[{device:'COM5',label:'COM5'}],poll:async()=>clone(state),
+        get_saved_model_info:async()=>null,set_gain:async()=>true,stop_controls:async()=>true,set_axes:async()=>true,
+        save_battery:async data=>{calls.battery++;await sleep(200);if(window.testBridge.failBattery)throw Error('Battery save failed');Object.keys(battery).forEach(k=>battery[k]=+data[k]);return clone(battery)},
+        save_link_settings:async data=>{calls.link++;await sleep(250);Object.keys(link).forEach(k=>link[k]=+data[k]);return clone(link)},
+        connect:async(port,baud,rate)=>{calls.connect.push({port,baud,rate});Object.assign(state,{connected:true,armed_known:true,app_state:'connected_disarmed',mode:'MANUAL',link:'LINK OK',link_quality:{grade:'excellent',probe_samples:20,rx_packets_30s:100,rtt_median_ms:24,rtt_p95_ms:40,probe_loss_percent:0,rx_sequence_loss_percent:0,heartbeat_age_s:.2}});return clone(state)},
+        disconnect:async()=>{Object.assign(state,{connected:false,armed_known:false,app_state:'disconnected'});return true},
+        reverse_motor:async servo=>{calls.reverse++;if(window.testBridge.failMotor)throw Error('Motor write failed');setTimeout(()=>state.servos[servo].direction*=-1,650);return true},
+        set_servo_function:async(servo,motor)=>{if(window.testBridge.failMotor)throw Error('Motor write failed');setTimeout(()=>Object.assign(state.servos[servo],{motor:motor||null,function:motor===0?0:motor<=8?32+motor:73+motor,direction:motor?1:null}),650);return true},
+        start_heavy_quality_test:async()=>{calls.heavy++;await sleep(250);state.heavy_quality={running:true,status:'Stage 1 of 3: 1 Hz',sent:4,replies:4,results:[]};return clone(state.heavy_quality)},
+        cancel_heavy_quality_test:async()=>{state.heavy_quality={running:false,status:'Cancelled',results:[]};return clone(state.heavy_quality)},
+        read_console:async()=>{calls.console++;return {rx:['RX sample '+calls.console],tx:['TX sample '+calls.console]}},
+        minimize_window:async()=>true,toggle_maximize_window:async()=>false,close_window:async()=>true
+      }};
+    });
+    await page.goto('http://127.0.0.1:'+server.address().port+'/web/index.html');
+    await page.waitForFunction(()=>bridgeReady);
+    const openLink=()=>page.locator('[data-open="link-modal"]').click();
+    const close=async id=>{await page.locator('#'+id+' [data-close]').first().click();await page.waitForFunction(id=>!document.getElementById(id).open,id)};
+    await openLink();
+    await page.locator('#baud').selectOption('115200');
+    await page.locator('#link-modal').getByRole('button',{name:'Cancel',exact:true}).click();
+    await page.waitForFunction(()=>!document.getElementById('link-modal').open);
+    await openLink();assert.equal(await page.locator('#baud').inputValue(),'57600');
+    await page.locator('#custom-port-input').fill('COM42');
+    await page.locator('#custom-port-btn').click();
+    assert(await page.locator('#link-modal').evaluate(d=>d.open));
+    assert.equal(await page.locator('#port').inputValue(),'COM42');
+    await page.locator('#baud').selectOption('115200');
+    assert(await page.locator('#link-form [type="submit"]').evaluate(el=>{el.click();return el.disabled}));
+    await page.waitForFunction(()=>!document.getElementById('link-modal').open);
+    await page.locator('#refresh').click();assert.equal(await page.locator('#port').inputValue(),'COM42');
+    await page.locator('#connect').click();
+    await page.waitForFunction(()=>testBridge.calls.connect.length===1);
+    assert.equal(await page.evaluate(()=>testBridge.calls.connect[0].baud),115200);
+    await page.locator('[data-open="battery-modal"]').click();
+    await page.locator('#battery-form [name="cells"]').fill('5');
+    await page.keyboard.press('Escape');await page.waitForFunction(()=>!document.getElementById('battery-modal').open);
+    await page.locator('[data-open="battery-modal"]').click();
+    assert.equal(await page.locator('#battery-form [name="cells"]').inputValue(),'4');
+    await page.evaluate(()=>testBridge.failBattery=true);
+    await page.locator('#battery-form').getByRole('button',{name:'Save battery'}).click();
+    await page.locator('#battery-form .form-feedback').waitFor({state:'visible'});
+    assert(await page.locator('#battery-modal').evaluate(d=>d.open));
+    assert.equal(await page.locator('#battery-form .form-feedback').textContent(),'Battery save failed');
+    await page.evaluate(()=>testBridge.failBattery=false);
+    await page.locator('#battery-form [name="cells"]').fill('5');
+    await page.locator('#battery-form').getByRole('button',{name:'Save battery'}).click();
+    await page.waitForFunction(()=>!document.getElementById('battery-modal').open);
+    await page.locator('[data-open="battery-modal"]').click();
+    assert.equal(await page.locator('#battery-form [name="cells"]').inputValue(),'5');
+    await page.screenshot({path:path.join(output,'battery.png')});await close('battery-modal');
+    await page.locator('[data-open="motors-modal"]').click();
+    assert.equal(await page.locator('#motor-list > .motor-row').count(),3);
+    await page.locator('#motor-list > .motor-row').first().getByRole('button').click();
+    await page.waitForFunction(()=>document.querySelector('#motor-list > .motor-row > span').textContent==='Confirming…');
+    assert(await page.locator('#motor-list > .motor-row').first().getByRole('button').isDisabled());
+    await page.waitForFunction(()=>document.querySelector('#motor-list > .motor-row > span').textContent==='Reversed');
+    await page.evaluate(()=>testBridge.failMotor=true);
+    await page.locator('#motor-list > .motor-row').first().locator('select').selectOption('2');
+    await page.locator('#motor-feedback').waitFor({state:'visible'});
+    assert.equal(await page.locator('#motor-list > .motor-row').first().locator('select').inputValue(),'1');
+    await page.screenshot({path:path.join(output,'motors.png')});await close('motors-modal');
+    await page.locator('#link-quality').click();
+    assert.equal(await page.locator('#quality-detail-rtt').textContent(),'24 ms');
+    await page.locator('#heavy-quality-run').click();
+    assert(await page.locator('#heavy-quality-run').isDisabled());
+    await page.locator('#heavy-quality-cancel').waitFor({state:'visible'});
+    assert.equal(await page.evaluate(()=>testBridge.calls.heavy),1);
+    await page.locator('#heavy-quality-cancel').click();
+    await page.waitForFunction(()=>!testBridge.state.heavy_quality.running);
+    await page.screenshot({path:path.join(output,'quality.png')});await close('link-quality-modal');
+    await page.locator('#console').click();
+    await page.waitForFunction(()=>document.getElementById('console-rx-output').textContent.includes('RX sample'));
+    await page.locator('#console-pause').click();
+    const paused=await page.locator('#console-rx-output').textContent();
+    await page.waitForTimeout(850);assert.equal(await page.locator('#console-rx-output').textContent(),paused);
+    await page.locator('#console-pause').click();
+    await page.waitForFunction(old=>document.getElementById('console-rx-output').textContent!==old,paused);
+    await page.screenshot({path:path.join(output,'console.png')});await close('console-modal');
+    for(const viewport of [{width:900,height:560},{width:480,height:720}]){
+      await page.setViewportSize(viewport);
+      for(const id of ['link-modal','battery-modal','link-quality-modal','motors-modal','console-modal']){
+        await page.evaluate(id=>openModal(id),id);
+        const box=await page.locator('#'+id).boundingBox();
+        assert(box.x>=0&&box.y>=0&&box.width<=viewport.width&&box.height<=viewport.height,id+' must fit viewport');
+        assert.equal(await page.evaluate(()=>canDrive()),false);
+        await close(id);
+      }
+    }
+    await page.setViewportSize({width:1080,height:720});await openLink();
+    await page.screenshot({path:path.join(output,'link.png')});await close('link-modal');
+    assert.deepEqual(errors,[]);
+    console.log('PASS: settings cancel/save/failure, saved baud, custom port rescan, motor confirmation/failure, heavy test, console pause/resume, keyboard gating, and five dialogs at two window sizes.');
+  }catch(error){
+    const page=browser.contexts()[0]?.pages()[0];
+    if(page){
+      await page.screenshot({path:path.join(output,'failure.png')});
+      console.error(await page.evaluate(()=>[...document.querySelectorAll('input')].filter(el=>!el.checkValidity()).map(el=>({name:el.name,value:el.value,error:el.validationMessage}))));
+    }
+    throw error;
+  }finally{await browser.close();await new Promise(resolve=>server.close(resolve))}
+}
+main().catch(error=>{console.error(error);server.close();process.exitCode=1});

SUB Control/web/app.js

@@ -6,7 +6,7 @@ const STATUS_LABELS = {
   link_degraded: 'Signal lost — check tether',
 };
 const $=s=>document.querySelector(s), $$=s=>[...document.querySelectorAll(s)];
-const control={forward:0,turn:0,vertical:0}, pressedKeys=new Set(); let bridgeReady=false, appState='disconnected', batteryConfig={}, servoSignature='', lastAxisSend=0, axisTimer=0, demoActive=false, demoState=null;
+const control={forward:0,turn:0,vertical:0}, pressedKeys=new Set(); let bridgeReady=false, appState='disconnected', batteryConfig={}, linkConfig={baud:57600,control_hz:20,ping_hz:1,system_hz:1,servo_hz:2,rc_hz:2,esc_hz:1}, servoSignature='', lastAxisSend=0, axisTimer=0, demoActive=false, demoState=null;
 const api=(name,...args)=>window.pywebview.api[name](...args);
 const activity=[];
 let lastReportedStatus='';
@@ -21,13 +21,14 @@ function withTimeout(promise,ms=1500){return new Promise((resolve,reject)=>{cons
 let vehicleSnapshot={connected:false,armed:null}, view=ControlState.present(vehicleSnapshot), inputFocused=true,
     bridgeStale=false,lastBridgeAt=performance.now(),axisBusy=false,inputSequence=Date.now(),
     localRequest=null,commandError='',requestSerial=0,demoCommandTimer=0,lastSafetyTick=performance.now();
-const canDrive=()=>view.drive&&performance.now()-lastSafetyTick<750;
+const canDrive=()=>view.drive&&!document.querySelector('dialog[open]')&&performance.now()-lastSafetyTick<750;
 window.canDrive=canDrive;
-function makeDemoState(){const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,label:i<=3?`Motor ${i}`:'Unassigned',motor:i<=3?i:null,direction:i<=3?1:null};return {connected:true,link:'LINK OK',vehicle:'DEMO • DISARMED',armed:false,armed_known:true,mode:'MANUAL',app_state:'connected_disarmed',status:'Demo mode ready — no hardware or spoofer.',battery:{voltage:15.8,per_cell:3.95,percent:72,cells:4,low:false},servos}}
+function makeDemoState(){const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,label:i<=3?`Motor ${i}`:'Unassigned',motor:i<=3?i:null,direction:i<=3?1:null};return {connected:true,link:'LINK OK',vehicle:'DEMO • DISARMED',armed:false,armed_known:true,mode:'MANUAL',app_state:'connected_disarmed',status:'Demo mode ready — no hardware or spoofer.',battery:{voltage:15.8,per_cell:3.95,percent:72,cells:4,low:false},link_quality:null,servos}}
 function updateDemo(patch){Object.assign(demoState,patch);render(demoState)}
 document.addEventListener('click',e=>{const btn=e.target.closest('.num-step');if(!btn)return;const pill=btn.closest('.number-pill');if(!pill)return;const input=pill.querySelector('input');if(!input)return;const step=+input.step||1,min=input.min!==''?+input.min:-Infinity,max=input.max!==''?+input.max:Infinity;let val=+input.value||0;if(btn.classList.contains('down'))val=Math.max(min,+(val-step).toFixed(4));else val=Math.min(max,+(val+step).toFixed(4));input.value=val;input.dispatchEvent(new Event('input',{bubbles:true}));input.dispatchEvent(new Event('change',{bubbles:true}))});
 function toast(message,error=false){const el=$('#toast');el.textContent=message;el.className=`toast show${error?' error':''}`;clearTimeout(toast.t);toast.t=setTimeout(()=>el.className='toast',2600)}
 window.showToast=toast;
+const manualPorts=new Map();
 function populatePorts(ports){
   const p=$('#port');
   if(!p)return;
@@ -50,6 +51,7 @@ function populatePorts(ports){
   };
 
   if(Array.isArray(ports)) ports.forEach(addPort);
+  manualPorts.forEach(addPort);
   addPort({device:'demo', label:'Demo Mode (no hardware)'});
 
   let matched=false;
@@ -94,7 +96,7 @@ function easeHeave(target=0){cancelAnimationFrame(heaveAnim);const sv=control.ve
 window.verticalControl={setPos:value=>{cancelAnimationFrame(heaveAnim);setHeave(value)},easeBack:()=>{if(heavePointer===null)easeHeave()},getState:()=>({value:control.vertical,active:heavePointer!==null})};
 
 function applyKeys(){if(!canDrive()){pressedKeys.clear();return;}const turn=(pressedKeys.has('d')||pressedKeys.has('e')?1:0)-(pressedKeys.has('a')||pressedKeys.has('q')?1:0),forward=(pressedKeys.has('w')?1:0)-(pressedKeys.has('s')?1:0),vertical=(pressedKeys.has('r')?1:0)-(pressedKeys.has('f')?1:0);if(!window.joystick3D?.getState().active)window.joystick3D?.easeTo(turn,-forward);if(heavePointer===null)easeHeave(vertical)}
-addEventListener('keydown',e=>{if(e.key==='F3'){e.preventDefault();if(!e.repeat&&view.action==='disarm')requestControl('disarm');return;}if(/^(INPUT|SELECT|TEXTAREA)$/.test(e.target.tagName))return;if(e.key==='F2'){e.preventDefault();if(!e.repeat)startEngageHold();return;}const k=e.key.toLowerCase();if('wasdqerf'.includes(k)&&k.length===1){if(!canDrive())return;e.preventDefault();if(!pressedKeys.has(k)){pressedKeys.add(k);applyKeys();}}});addEventListener('keyup',e=>{if(e.key==='F2'){e.preventDefault();cancelEngageHold(true);return;}const k=e.key.toLowerCase();if(pressedKeys.delete(k))applyKeys();});
+addEventListener('keydown',e=>{if(e.key==='F3'){e.preventDefault();if(!e.repeat&&view.action==='disarm')requestControl('disarm');return;}if(document.querySelector('dialog[open]')||/^(INPUT|SELECT|TEXTAREA)$/.test(e.target.tagName))return;if(e.key==='F2'){e.preventDefault();if(!e.repeat)startEngageHold();return;}const k=e.key.toLowerCase();if('wasdqerf'.includes(k)&&k.length===1){if(!canDrive())return;e.preventDefault();if(!pressedKeys.has(k)){pressedKeys.add(k);applyKeys();}}});addEventListener('keyup',e=>{if(e.key==='F2'){e.preventDefault();cancelEngageHold(true);return;}const k=e.key.toLowerCase();if(pressedKeys.delete(k))applyKeys();});
 function resetInputs(){
   if(gainPointer!==null)releaseGain({pointerId:gainPointer});
   clearTimeout(axisTimer);axisTimer=0;pressedKeys.clear();cancelEngageHold(false);
@@ -111,28 +113,62 @@ addEventListener('focus',()=>focusChanged(!document.hidden));
 document.addEventListener('visibilitychange',()=>focusChanged(!document.hidden&&document.hasFocus()));
 addEventListener('pagehide',()=>focusChanged(false));
 
+function setFeedback(el,message=''){
+  if(!el)return;
+  el.textContent=message;el.hidden=!message;
+}
 function openModal(id){
   const el=typeof id==='string'?document.getElementById(id):id;
-  if(!el)return;
+  if(!el||el.open)return;
+  resetInputs();
+  el._returnFocus=document.activeElement;
+  if(el.id==='battery-modal')fillBatteryForm();
+  if(el.id==='link-modal'){
+    fillLinkForm();
+    $('#custom-port-status').textContent='';
+    $('#custom-port-input').value='';
+  }
+  el.querySelectorAll('.form-feedback').forEach(feedback=>setFeedback(feedback));
   el.classList.remove('closing');
-  if(!el.open)el.showModal();
+  el.showModal();
 }
 function closeModal(dialog){
-  if(!dialog||!dialog.open||dialog.classList.contains('closing'))return;
+  if(!dialog||!dialog.open||dialog.classList.contains('closing')||dialog.querySelector('[data-busy="true"]'))return;
   dialog.classList.add('closing');
   let done=false;
   const finish=()=>{
     if(done)return;
     done=true;
-    dialog.removeEventListener('animationend',finish);
+    dialog.removeEventListener('animationend',onEnd);
     dialog.classList.remove('closing');
     dialog.close();
+    if(dialog._returnFocus?.isConnected)dialog._returnFocus.focus({preventScroll:true});
   };
-  dialog.addEventListener('animationend',finish,{once:true});
+  const onEnd=e=>{if(e.target===dialog)finish()};
-  setTimeout(finish,300);
+  dialog.addEventListener('animationend',onEnd);
+  setTimeout(finish,180);
 }
 $$('[data-open]').forEach(b=>b.onclick=()=>openModal(b.dataset.open));
 $$('[data-close]').forEach(b=>b.onclick=()=>closeModal(b.closest('dialog')));
+$('#link-quality').onclick=()=>openModal('link-quality-modal');
+let heavyActionBusy=false;
+async function requestHeavyTest(action){
+  if(heavyActionBusy)return;
+  heavyActionBusy=true;
+  setFeedback($('#heavy-quality-error'));
+  renderHeavyQuality(vehicleSnapshot.heavy_quality,vehicleSnapshot.connected,vehicleSnapshot.armed);
+  try{
+    const test=await api(action);
+    vehicleSnapshot.heavy_quality=test;
+    renderHeavyQuality(test,vehicleSnapshot.connected,vehicleSnapshot.armed);
+  }catch(e){setFeedback($('#heavy-quality-error'),e.message||'Link test unavailable. Try again.')}
+  finally{
+    heavyActionBusy=false;
+    renderHeavyQuality(vehicleSnapshot.heavy_quality,vehicleSnapshot.connected,vehicleSnapshot.armed);
+  }
+}
+$('#heavy-quality-run').onclick=()=>requestHeavyTest('start_heavy_quality_test');
+$('#heavy-quality-cancel').onclick=()=>requestHeavyTest('cancel_heavy_quality_test');
 $$('dialog').forEach(d=>{
   d.addEventListener('cancel',e=>{e.preventDefault();closeModal(d)});
   d.addEventListener('click',e=>{
@@ -255,7 +291,7 @@ $('#connect').onclick=async()=>{
     recordActivity(`Connecting to ${port}…`);
     toast(`Connecting to ${port}…`);
     try{
-      const confirmedState=await api('connect',port,+$('#baud').value,+$('#rate').value);
+      const confirmedState=await api('connect',port,+linkConfig.baud||57600,+linkConfig.control_hz||20);
       if(confirmedState)render(confirmedState);
       toast(confirmedState?.armed_known?'MAVLink connected':'Waiting for vehicle telemetry',!confirmedState?.armed_known);
     }catch(e){
@@ -270,7 +306,9 @@ const customPortBtn=$('#custom-port-btn'), customPortInput=$('#custom-port-input
 if(customPortBtn&&customPortInput){
   const applyCustomPort=()=>{
     const val=customPortInput.value.trim();
-    if(!val)return;
+    if(!val){$('#custom-port-status').textContent='Enter a port first.';customPortInput.focus();return;}
+    if(vehicleSnapshot.connected)return;
+    manualPorts.set(val,{device:val,label:`Custom (${val})`});
     const p=$('#port');
     let exists=false;
     for(const opt of p.options){
@@ -280,8 +318,7 @@ if(customPortBtn&&customPortInput){
       p.add(new Option(`Custom (${val})`, val), 0);
       p.value=val;
     }
-    closeModal($('#link-modal'));
+    $('#custom-port-status').textContent=`Selected ${val}. Apply settings, then connect.`;
-    toast(`Selected port: ${val}`);
   };
   customPortBtn.onclick=applyCustomPort;
   customPortInput.onkeydown=e=>{if(e.key==='Enter'){e.preventDefault();applyCustomPort();}};
@@ -380,6 +417,34 @@ if(engageButton){
 }
 
 $('#logs').onclick=()=>api('open_logs');
+const consoleDialog=$('#console-modal'),consoleRx=$('#console-rx-output'),consoleTx=$('#console-tx-output');
+let consoleRefreshBusy=false,consolePaused=false;
+$('#console-pause').onclick=()=>{
+  consolePaused=!consolePaused;
+  $('#console-pause').textContent=consolePaused?'Resume':'Pause';
+  $('#console-pause').setAttribute('aria-pressed',String(consolePaused));
+  $('#console-state').textContent=consolePaused?'Paused · session logging continues':'Live · follows new messages';
+  if(!consolePaused)refreshConsole();
+};
+async function refreshConsole(){
+  if(!consoleDialog?.open||!bridgeReady||consoleRefreshBusy||consolePaused)return;
+  consoleRefreshBusy=true;
+  try{
+    const rxAtBottom=consoleRx.scrollHeight-consoleRx.scrollTop-consoleRx.clientHeight<36;
+    const txAtBottom=consoleTx.scrollHeight-consoleTx.scrollTop-consoleTx.clientHeight<36;
+    const sides=await api('read_console',150);
+    if(consolePaused||!consoleDialog.open)return;
+    consoleRx.textContent=sides.rx?.length?sides.rx.join('\n'):'Waiting for vehicle data…';
+    consoleTx.textContent=sides.tx?.length?sides.tx.join('\n'):'Waiting for transmitted data…';
+    if(rxAtBottom)consoleRx.scrollTop=consoleRx.scrollHeight;
+    if(txAtBottom)consoleTx.scrollTop=consoleTx.scrollHeight;
+  }catch(error){
+    $('#console-state').textContent=`Console unavailable: ${error.message}`;
+  }
+  finally{consoleRefreshBusy=false}
+}
+$('#console').onclick=()=>{openModal(consoleDialog);refreshConsole()};
+setInterval(refreshConsole,750);
 function setGain(value){const gain=$('#gain');gain.value=Math.max(+gain.min,Math.min(+gain.max,value));$('#gain-value').textContent=`${gain.value}%`;if(bridgeReady)api('set_gain',+gain.value)}
 $('#gain').oninput=e=>setGain(+e.target.value);$('#gain-down').onclick=()=>setGain(+$('#gain').value-5);$('#gain-up').onclick=()=>setGain(+$('#gain').value+5);
 // Explicit pointer ownership makes the full range rail a reliable touch target
@@ -391,9 +456,108 @@ gainSlider.addEventListener('pointerdown',e=>{if(gainPointer!==null||e.button>0)
 gainSlider.addEventListener('pointermove',e=>{if(e.pointerId===gainPointer)gainFromPointer(e)});
 ['pointerup','pointercancel','lostpointercapture'].forEach(type=>gainSlider.addEventListener(type,releaseGain));
 gainSlider.addEventListener('keydown',e=>{const delta={ArrowRight:1,ArrowUp:1,ArrowLeft:-1,ArrowDown:-1}[e.key];if(delta){e.preventDefault();setGain(+gainSlider.value+delta)}else if(e.key==='Home'||e.key==='End'){e.preventDefault();setGain(+(e.key==='Home'?gainSlider.min:gainSlider.max))}});
-$('#battery-form').onsubmit=async e=>{e.preventDefault();const data=Object.fromEntries(new FormData(e.target));try{batteryConfig=await api('save_battery',data);closeModal($('#battery-modal'));toast('Battery settings saved')}catch(err){toast(err.message,true)}};
+async function saveSettings(form,method,commit,message){
+  if(form.dataset.busy==='true'||!form.reportValidity())return;
+  const data=Object.fromEntries(new FormData(form));
+  const button=form.querySelector('[type="submit"]'),label=button.textContent;
+  const disabled=new Map([...form.querySelectorAll('input,select,button')].map(el=>[el,el.disabled]));
+  form.dataset.busy='true';disabled.forEach((_,el)=>el.disabled=true);button.textContent='Saving…';
+  setFeedback(form.querySelector('.form-feedback'));
+  let saved=false;
+  try{commit(await api(method,data));saved=true;toast(message)}
+  catch(error){setFeedback(form.querySelector('.form-feedback'),error.message||'Could not save settings. Try again.')}
+  finally{
+    delete form.dataset.busy;disabled.forEach((value,el)=>el.disabled=value);button.textContent=label;
+    if(saved)closeModal(form.closest('dialog'));
+  }
+}
+$('#battery-form').onsubmit=e=>{e.preventDefault();saveSettings(e.target,'save_battery',value=>batteryConfig=value,'Battery settings saved')};
 function fillBatteryForm(){for(const [k,v] of Object.entries(batteryConfig)){const el=$(`#battery-form [name=${k}]`);if(el)el.value=v}}
-function renderMotors(servos){const signature=JSON.stringify(servos);if(signature===servoSignature)return;servoSignature=signature;const list=$('#motor-list');list.innerHTML='';for(let i=1;i<=16;i++){const s=servos[String(i)]||{},row=document.createElement('div');row.className='motor-row';const opts=['<option value="0">Unassigned</option>',...Array.from({length:12},(_,n)=>`<option value="${n+1}" ${s.motor===n+1?'selected':''}>Motor ${n+1}</option>`)].join('');row.innerHTML=`<strong>SERVO${i}</strong><select aria-label="SERVO${i} function">${opts}</select><span>${s.direction==null?'—':s.direction===-1?'Reversed':'Normal'}</span><button class="button subtle">Reverse</button>`;row.querySelector('select').onchange=e=>{if(demoActive){const motor=+e.target.value;demoState.servos[String(i)]={function:motor?32+motor:0,label:motor?`Motor ${motor}`:'Unassigned',motor:motor||null,direction:motor?1:null};servoSignature='';renderMotors(demoState.servos);toast(`Demo SERVO${i} updated`)}else api('set_servo_function',i,+e.target.value).catch(x=>toast(x.message,true))};row.querySelector('button').onclick=()=>{if(demoActive){if(s.motor){s.direction=s.direction===-1?1:-1;servoSignature='';renderMotors(demoState.servos);toast(`Demo Motor ${s.motor} reversed`)}else toast(`SERVO${i} is unassigned`,true)}else api('reverse_motor',i).catch(x=>toast(x.message,true))};list.append(row)}}
+$('#link-form').onsubmit=e=>{e.preventDefault();saveSettings(e.target,'save_link_settings',value=>linkConfig=value,'Link settings applied')};
+function fillLinkForm(){for(const [k,v] of Object.entries(linkConfig)){const el=$(`#link-form [name=${k}]`);if(el)el.value=v}}
+const motorEdits=new Map();
+async function requestMotorEdit(servo,kind,value){
+  if(motorEdits.has(servo))return;
+  const s=vehicleSnapshot.servos?.[String(servo)]||{};
+  const expected=kind==='function'?(value===0?0:value<=8?32+value:73+value):-s.direction;
+  setFeedback($('#motor-feedback'));
+  if(demoActive){
+    if(kind==='function')Object.assign(s,{function:expected,motor:value||null,direction:value?1:null});
+    else s.direction=expected;
+    servoSignature='';renderMotors(demoState.servos);toast('Demo motor updated');return;
+  }
+  motorEdits.set(servo,{kind,expected,started:performance.now()});
+  servoSignature='';renderMotors(vehicleSnapshot.servos||{});
+  try{
+    await api(kind==='function'?'set_servo_function':'reverse_motor',servo,...(kind==='function'?[value]:[]));
+  }catch(error){
+    motorEdits.delete(servo);
+    setFeedback($('#motor-feedback'),error.message||'Motor change failed. Try again.');
+    servoSignature='';renderMotors(vehicleSnapshot.servos||{});
+  }
+}
+function renderMotors(servos){
+  for(const [servo,edit] of motorEdits){
+    const s=servos[String(servo)]||{};
+    if((edit.kind==='function'?s.function:s.direction)===edit.expected){
+      motorEdits.delete(servo);toast(`SERVO${servo} change confirmed`);
+    }else if(!vehicleSnapshot.connected||performance.now()-edit.started>8000){
+      motorEdits.delete(servo);
+      setFeedback($('#motor-feedback'),`SERVO${servo}: confirmation not received. Check the reported assignment before retrying.`);
+    }
+  }
+  const editable=!!vehicleSnapshot.connected&&!vehicleSnapshot.armed&&(demoActive||view.known);
+  const assigned=Object.values(servos).filter(s=>s.motor).length;
+  $('#motor-status').textContent=vehicleSnapshot.armed?'Disarm to change assignments or direction.':!vehicleSnapshot.connected?'Connect to read motor outputs.':assigned?`${assigned} motor${assigned===1?'':'s'} assigned · changes wait for vehicle confirmation.`:'Reading motor assignments…';
+  const signature=JSON.stringify([servos,editable,[...motorEdits]]);
+  if(signature===servoSignature)return;
+  servoSignature=signature;
+  const list=$('#motor-list'),expanded=list.querySelector('details')?.open;
+  list.replaceChildren();
+  const other=document.createElement('details');other.className='motor-other';other.open=!!expanded;
+  const summary=document.createElement('summary');summary.textContent=`Other outputs (${16-assigned})`;other.append(summary);
+  for(let i=1;i<=16;i++){
+    const s=servos[String(i)]||{},pending=motorEdits.get(i),row=document.createElement('div');row.className='motor-row';
+    row.innerHTML=`<strong>SERVO${i}</strong><select aria-label="SERVO${i} assignment"></select><span></span><button type="button" class="button subtle">Reverse</button>`;
+    const select=row.querySelector('select');
+    select.add(new Option(s.function==null?'Reading…':'Unassigned','0'));
+    for(let motor=1;motor<=12;motor++)select.add(new Option(`Motor ${motor}`,String(motor)));
+    select.value=String(s.motor||0);
+    select.disabled=!editable||!!pending||s.function==null;
+    select.onchange=e=>requestMotorEdit(i,'function',+e.target.value);
+    row.querySelector('span').textContent=pending?'Confirming…':s.direction==null?'—':s.direction===-1?'Reversed':'Normal';
+    const reverse=row.querySelector('button');reverse.disabled=!editable||!!pending||!s.motor||s.direction==null;
+    reverse.setAttribute('aria-label',`Reverse SERVO${i} motor direction`);
+    reverse.onclick=()=>requestMotorEdit(i,'direction');
+    (s.motor?list:other).append(row);
+  }
+  if(!assigned){const empty=document.createElement('p');empty.className='note';empty.textContent='Assigned motors will appear here.';list.append(empty)}
+  if(assigned<16)list.append(other);
+}
+function renderHeavyQuality(test,connected,armed){
+  const status=$('#heavy-quality-status'),results=$('#heavy-quality-results'),run=$('#heavy-quality-run'),stop=$('#heavy-quality-cancel');
+  if(!status||!results||!run||!stop)return;
+  const quality=demoActive?null:vehicleSnapshot.link_quality;
+  $('#quality-detail-rtt').textContent=quality?.rtt_median_ms==null?'—':`${Math.round(quality.rtt_median_ms)} ms`;
+  $('#quality-detail-loss').textContent=quality?.probe_loss_percent==null?'—':`${quality.probe_loss_percent.toFixed(1)}%`;
+  $('#quality-detail-downlink').textContent=quality?.rx_sequence_loss_percent==null?'—':`${quality.rx_sequence_loss_percent.toFixed(1)}%`;
+  const running=!!test?.running;
+  status.textContent=running?`${test.status} · ${test.replies||0}/${test.sent||0} replies`:(test?.status==='Complete'?'Test complete. Results below.':test?.status==='Cancelled'?'Test stopped. Partial results below.':demoActive?'Demo has no hardware link to measure.':!connected?'Connect to run a test.':armed?'Disarm to run a test.':'Ready to test.');
+  run.disabled=heavyActionBusy||running||!connected||armed||demoActive;
+  run.textContent=!connected?'Connect to run test':armed?'Disarm to run test':demoActive?'Unavailable in demo':test?.status==='Complete'?'Run again':'Run heavy test';
+  stop.hidden=!running;
+  stop.disabled=heavyActionBusy;
+  results.replaceChildren();
+  for(const row of test?.results||[]){
+    const line=document.createElement('div');line.className='heavy-result-row';
+    const rate=document.createElement('strong');rate.textContent=`${row.rate_hz} Hz`;
+    const stats=document.createElement('span');
+    const loss=row.loss_percent==null?'—':`${row.loss_percent.toFixed(1)}% loss`;
+    const rtt=row.median_rtt_ms==null?'—':`${row.median_rtt_ms.toFixed(0)} ms median / ${row.p95_rtt_ms.toFixed(0)} ms p95`;
+    stats.textContent=`${row.replies}/${row.sent} replies · ${loss} · ${rtt}`;
+    line.append(rate,stats);results.append(line);
+  }
+}
 function render(s,confirmed=false){
   vehicleSnapshot=s;
   if(confirmed&&localRequest?.sent && (s.pending_command===localRequest.name || s.command_error ||
@@ -402,10 +566,13 @@ function render(s,confirmed=false){
   view=ControlState.present(s,{stale:bridgeStale,focused:inputFocused,pending:localRequest?.name,error:commandError});
   if((previous.drive&&!view.drive)||(previous.action==='arm'&&view.action!=='arm'))resetInputs();
   appState=bridgeStale&&s.connected?'link_degraded':s.app_state||'disconnected';
+  renderHeavyQuality(s.heavy_quality,s.connected,s.armed);
   document.body.dataset.appState=appState;
   document.body.dataset.controlsEnabled=String(view.drive);
   document.body.dataset.telemetryStale=String(!view.known||!!s.battery_stale);
   $('#port').disabled=!!s.connected;
+  $('#custom-port-input').disabled=!!s.connected||$('#link-form').dataset.busy==='true';
+  $('#custom-port-btn').disabled=!!s.connected||$('#link-form').dataset.busy==='true';
   const isOnline=(appState==='connected_disarmed'||appState==='armed');
   const connectBtn=$('#connect');
   const connectLabel=connectBtn?connectBtn.querySelector('.btn-label'):null;
@@ -456,6 +623,37 @@ function render(s,confirmed=false){
     $('#battery-percent').textContent='waiting';
     $('#battery-fill').style.width='0';
   }
+  const quality=s.link_quality,qualityCard=$('#link-quality');
+  if(qualityCard){
+    if(demoActive){
+      qualityCard.dataset.grade='offline';
+      $('#link-quality-grade').textContent='Demo';
+      $('#link-quality-roundtrip').textContent='no hardware link test';
+      $('#link-quality-downlink').textContent='';
+      renderMotors(s.servos||{});
+      return;
+    }
+    const grade=quality?.grade||(s.connected?'testing':'offline');
+    qualityCard.dataset.grade=grade;
+    $('#link-quality-grade').textContent=grade.charAt(0).toUpperCase()+grade.slice(1);
+    if(quality&&quality.probe_samples){
+      const percent=value=>value==null?'—':`${value.toFixed(1)}%`;
+      const median=quality.rtt_median_ms==null?'—':`${Math.round(quality.rtt_median_ms)} ms`;
+      const p95=quality.rtt_p95_ms==null?'—':`${Math.round(quality.rtt_p95_ms)} ms`;
+      $('#link-quality-roundtrip').textContent=`round trip ${median} / ${p95} p95 • loss ${percent(quality.probe_loss_percent)}`;
+      const downLoss=percent(quality.rx_sequence_loss_percent);
+      const badFrames=quality.rx_corrupt_frames_20s??0;
+      const badBytes=quality.rx_corrupt_bytes_20s??0;
+      const age=quality.heartbeat_age_s==null?'—':`${quality.heartbeat_age_s.toFixed(1)} s`;
+      $('#link-quality-downlink').textContent=`FC → PC loss ${downLoss} • ${badFrames} bad frames (${badBytes} B) • heartbeat ${age}`;
+      if(quality.probe_samples<10||quality.rx_packets_30s<10){
+        $('#link-quality-grade').textContent=`Testing ${Math.min(quality.probe_samples,quality.rx_packets_30s)}/10`;
+      }
+    }else{
+      $('#link-quality-roundtrip').textContent=s.connected?'testing round trip…':'waiting for connection';
+      $('#link-quality-downlink').textContent='';
+    }
+  }
   renderMotors(s.servos||{});
 }
 
@@ -564,8 +762,10 @@ async function boot(){
     populatePorts(await withTimeout(api('refresh_ports'),4000));
     const init=await withTimeout(api('initial_state'),4000);
     batteryConfig=init.battery_config||{};
+    linkConfig=init.link_config||{};
     populatePorts(init.ports);
     fillBatteryForm();
+    fillLinkForm();
     bridgeReady=true;booted=true;lastBridgeAt=performance.now();
     if(!demoActive)render(init.state);
     poll();

SUB Control/web/index.html

@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width,initial-scale=1">
   <title>Sub Control</title>
-  <link rel="stylesheet" href="styles.css?v=20260827-model-layout-v14">
+  <link rel="stylesheet" href="styles.css?v=20260930-dialogs-v1">
 </head>
 <body>
   <main class="app-shell">
@@ -50,13 +50,19 @@
         <b><em id="battery-fill"></em></b>
       </button>
 
+      <button id="link-quality" type="button" class="link-quality" data-grade="offline" title="Open link-quality details" aria-haspopup="dialog" aria-controls="link-quality-modal">
+        <span class="link-quality-dot" aria-hidden="true"></span>
+        <span><small>Data link</small><strong id="link-quality-grade">Offline</strong></span>
+        <i><span id="link-quality-roundtrip">waiting for connection</span><span id="link-quality-downlink"></span></i>
+      </button>
+
       <div class="deck-status-bar">
         <ol class="activity-history" aria-label="Last three events" aria-live="polite">
           <li id="activity-oldest" hidden></li>
           <li id="activity-previous" hidden></li>
           <li id="status-text">Not connected</li>
         </ol>
-        <header class="activity-heading"><span>Recent activity</span><a id="logs" class="logs-link" title="Open session logs" aria-label="Open session logs">Logs</a></header>
+        <header class="activity-heading"><span>Recent activity</span><span class="activity-actions"><button type="button" id="console" class="logs-link" title="Read live console" aria-label="Read live console">Console</button><button type="button" id="logs" class="logs-link" title="Open session logs" aria-label="Open session logs">Logs</button></span></header>
       </div>
       </section>
 
@@ -146,14 +152,64 @@
   <div id="toast" class="toast"></div>
 
   <!-- Modals -->
-  <dialog id="link-modal" class="modal"><button class="modal-close" data-close>×</button><small>connection</small><h2>Link Settings</h2><div class="form-grid two"><label><span>Baud rate</span><select id="baud"><option>9600</option><option>19200</option><option>38400</option><option selected>57600</option><option>115200</option></select></label><label><span>Control rate</span><select id="rate"><option>10</option><option selected>20</option></select></label></div><div style="margin-top:14px;"><label style="display:flex;flex-direction:column;gap:6px;"><span style="font-size:11px;font-weight:500;color:var(--muted)">Custom Port / Endpoint</span><div style="display:flex;gap:8px;"><input id="custom-port-input" placeholder="e.g. COM3 or tcp:127.0.0.1:5760" style="flex:1;height:32px;padding:0 12px;font-size:11px;"><button type="button" id="custom-port-btn" class="button subtle" style="white-space:nowrap;">Use Port</button></div></label></div><p class="note" style="margin-top:14px;">20 Hz is recommended for smooth intermediate commands on this link.</p></dialog>
+  <dialog id="link-modal" class="modal" aria-labelledby="link-title">
-  <dialog id="battery-modal" class="modal"><button class="modal-close" data-close>×</button><small>Power</small><h2>Battery Settings</h2><form id="battery-form" class="form-grid three"><label><span>Cells (S)</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="cells" type="number" min="1" step="1"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Capacity (mAh)</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="capacity_mah" type="number" min="1" step="50"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>C rating</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="c_rating" type="number" min="1" step=".1"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Full V / cell</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="full_v_per_cell" type="number" step=".01"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Empty V / cell</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="empty_v_per_cell" type="number" step=".01"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Warning %</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="warning_percent" type="number" min="0" max="100" step="1"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><div class="modal-actions wide"><button type="button" class="button subtle" data-close>Cancel</button><button class="button connect-button">Save Settings</button></div></form></dialog>
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Connection</small><h2 id="link-title">Link settings</h2>
-  <dialog id="motors-modal" class="modal motor-modal"><button class="modal-close" data-close>×</button><small>configuration</small><h2>Motor Outputs</h2><p class="note">Function and direction are read one parameter at a time to protect the low-bandwidth link.</p><div class="motor-head"><span>Output</span><span>Function</span><span>Direction</span><span></span></div><div id="motor-list" class="motor-list"></div></dialog>
+    <form id="link-form">
+      <section class="settings-section"><h3>Serial connection</h3>
+        <div class="form-grid two"><label><span>Baud rate</span><select id="baud" name="baud"><option value="9600">9600</option><option value="19200">19200</option><option value="38400">38400</option><option value="57600" selected>57600</option><option value="115200">115200</option></select></label><label><span>Control rate · Hz</span><select id="rate" name="control_hz"><option value="10">10</option><option value="20" selected>20</option></select></label></div>
+        <p class="note">Baud changes apply on the next connection.</p>
+        <label class="custom-port-label"><span>Custom port or endpoint</span><div class="custom-port-row"><input id="custom-port-input" placeholder="COM3 or tcp:127.0.0.1:5760" autocomplete="off"><button type="button" id="custom-port-btn" class="button subtle">Use port</button></div></label>
+        <p id="custom-port-status" class="note" role="status"></p>
+      </section>
+      <section class="settings-section"><h3>Live updates</h3>
+        <div class="form-grid two">
+          <label><span>Quality check · Hz</span><select name="ping_hz"><option value="1" selected>1</option><option value="2">2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>Battery / system · Hz</span><select name="system_hz"><option value="0">Off</option><option value="1" selected>1</option><option value="2">2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>Motor outputs · Hz</span><select name="servo_hz"><option value="0">Off</option><option value="1">1</option><option value="2" selected>2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>RC channels · Hz</span><select name="rc_hz"><option value="0">Off</option><option value="1">1</option><option value="2" selected>2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>ESC telemetry · Hz</span><select name="esc_hz"><option value="0">Off</option><option value="1" selected>1</option><option value="2">2</option><option value="5">5</option><option value="10">10</option></select></label>
+        </div>
+        <p class="note">Lower rates leave more bandwidth for controls. Vehicle telemetry rates reset after a reboot.</p>
+      </section>
+      <p class="form-feedback" role="alert" hidden></p>
+      <div class="modal-actions"><button type="button" class="button subtle" data-close>Cancel</button><button type="submit" class="button modal-primary">Apply settings</button></div>
+    </form>
+  </dialog>
+  <dialog id="link-quality-modal" class="modal quality-modal" aria-labelledby="quality-title">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Connection</small><h2 id="quality-title">Link quality</h2>
+    <p class="note">The live check watches round-trip replies, incoming packet loss, and heartbeat freshness.</p>
+    <div class="quality-summary"><div><span>Round trip</span><strong id="quality-detail-rtt">—</strong></div><div><span>Probe loss</span><strong id="quality-detail-loss">—</strong></div><div><span>FC → PC loss</span><strong id="quality-detail-downlink">—</strong></div></div>
+    <section class="heavy-test-panel"><h3>Extended test</h3><p class="note">Checks 1, 5, then 10 Hz for about 35 seconds. Run while disarmed; the live echo resumes afterward.</p>
+      <div id="heavy-quality-status" class="heavy-quality-status" role="status">Connect to run an extended test.</div>
+      <div id="heavy-quality-results" class="heavy-quality-results"></div>
+      <p id="heavy-quality-error" class="form-feedback" role="alert" hidden></p>
+      <div class="modal-actions"><button id="heavy-quality-run" type="button" class="button modal-primary">Run extended test</button><button id="heavy-quality-cancel" type="button" class="button subtle" hidden>Stop test</button></div>
+    </section>
+  </dialog>
+  <dialog id="battery-modal" class="modal" aria-labelledby="battery-title-modal">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Power</small><h2 id="battery-title-modal">Battery settings</h2><p class="note">Charge is estimated from voltage. Capacity and C rating describe your battery.</p>
+    <form id="battery-form">
+      <div class="form-grid two"><label><span>Cells · S</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Cells · S">‹</button><input name="cells" type="number" min="1" step="1" max="16" required><button type="button" class="num-step up" aria-label="Increase Cells · S">›</button></div></label><label><span>Capacity · mAh</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Capacity · mAh">‹</button><input name="capacity_mah" type="number" min="50" step="50" required><button type="button" class="num-step up" aria-label="Increase Capacity · mAh">›</button></div></label><label><span>C rating</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease C rating">‹</button><input name="c_rating" type="number" min="1" step="0.1" required><button type="button" class="num-step up" aria-label="Increase C rating">›</button></div></label><label><span>Low charge warning · %</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Low charge warning · %">‹</button><input name="warning_percent" type="number" min="0" step="1" max="100" required><button type="button" class="num-step up" aria-label="Increase Low charge warning · %">›</button></div></label></div>
+      <section class="settings-section"><h3>Voltage per cell</h3><div class="form-grid two"><label><span>Full · V</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Full · V">‹</button><input name="full_v_per_cell" type="number" min="0.01" step="0.01" required><button type="button" class="num-step up" aria-label="Increase Full · V">›</button></div></label><label><span>Empty · V</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Empty · V">‹</button><input name="empty_v_per_cell" type="number" min="0.01" step="0.01" required><button type="button" class="num-step up" aria-label="Increase Empty · V">›</button></div></label></div></section>
+      <p class="form-feedback" role="alert" hidden></p>
+      <div class="modal-actions"><button type="button" class="button subtle" data-close>Cancel</button><button type="submit" class="button modal-primary">Save battery</button></div>
+    </form>
+  </dialog>
+  <dialog id="motors-modal" class="modal motor-modal" aria-labelledby="motors-title">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Configuration</small><h2 id="motors-title">Motor outputs</h2><p id="motor-status" class="note" role="status">Waiting for motor assignments.</p>
+    <p id="motor-feedback" class="form-feedback" role="alert" hidden></p>
+    <div class="motor-head"><span>Output</span><span>Assignment</span><span>Direction</span><span></span></div><div id="motor-list" class="motor-list"></div>
+  </dialog>
+  <dialog id="console-modal" class="modal console-modal" aria-labelledby="console-title">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Local session</small><h2 id="console-title">Live console</h2>
+    <div class="console-toolbar"><p id="console-state" class="note" role="status">Live · follows new messages</p><button id="console-pause" type="button" class="button subtle" aria-pressed="false">Pause</button></div>
+    <div class="console-split"><section><header><i class="rx-dot"></i><span>RX</span><small>Vehicle → PC</small></header><pre id="console-rx-output" tabindex="0" aria-label="Received messages">Waiting for vehicle data…</pre></section><section><header><i class="tx-dot"></i><span>TX</span><small>PC → Vehicle</small></header><pre id="console-tx-output" tabindex="0" aria-label="Sent messages">Waiting for transmitted data…</pre></section></div>
+  </dialog>
 
   <script src="model-viewer.js?v=20260826-controls-v2"></script>
   <script src="joystick-3d.js?v=20260827-keyboard-v7"></script>
   <script src="control-state.js?v=20260827-state-v1"></script>
-  <script src="app.js?v=20260827-keyboard-v7"></script>
+  <script src="app.js?v=20260930-dialogs-v1"></script>
   <script src="cursor-light.js?v=20260827-directional-v10"></script>
 </body>
 </html>

SUB Control/web/styles.css

@@ -539,6 +539,7 @@ body[data-app-state="link_degraded"] .status-line .status-dot {
   margin-left: auto;
 }
 .logs-link:hover { color: #f1f4f2; }
+.activity-actions { display:flex; align-items:center; gap:12px; }
 
 /* ══════════════════════════════════════════════════════════════════
    PRIMARY CONTROL ZONE (Workspace)
@@ -554,6 +555,59 @@ body[data-app-state="link_degraded"] .status-line .status-dot {
   min-width: 0;
   position: relative;
 }
+
+/* ── Active MAVLink link test ── */
+.link-quality {
+  display: grid;
+  grid-template-columns: 8px minmax(0, 1fr);
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+  min-height: 48px;
+  padding: 3px 0;
+  color: #eef2f0;
+  width: 100%;
+  border: 0;
+  text-align: left;
+  font: inherit;
+  background: transparent;
+  cursor: pointer;
+  border-radius: 9px;
+  transition: background-color .18s ease;
+}
+.link-quality:hover,.link-quality:focus-visible { background:rgba(255,255,255,.055); outline:none; }
+.link-quality-dot {
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: #667074;
+}
+.link-quality span:not(.link-quality-dot) { display:flex; flex-direction:column; gap:1px; min-width:0; }
+.link-quality small { color:#8d979a; font-size:10px; font-weight:400; }
+.link-quality strong { font-size:14px; font-weight:500; line-height:1.15; }
+.link-quality i {
+  grid-column: 2;
+  min-width: 0;
+  color: #aab2b4;
+  font-size: 11px;
+  line-height: 1.3;
+  font-style: normal;
+  white-space: normal;
+  overflow-wrap: anywhere;
+}
+.link-quality i span { display:block; }
+.link-quality[data-grade="excellent"] .link-quality-dot { background:#bce96c; box-shadow:0 0 8px rgba(188,233,108,.35); }
+.link-quality[data-grade="good"] .link-quality-dot { background:#85c7e8; }
+.link-quality[data-grade="fair"] .link-quality-dot { background:#e7bf69; }
+.link-quality[data-grade="poor"] .link-quality-dot { background:#f07f78; box-shadow:0 0 8px rgba(240,127,120,.3); }
+.link-quality[data-grade="testing"] .link-quality-dot { background:#aab3b6; }
+.quality-modal { width:min(520px,calc(100vw - 32px)); }
+.heavy-test-panel { margin-top:18px; padding-top:14px; border-top:1px solid rgba(128,145,145,.2); }
+.heavy-quality-status { font-size:14px; font-weight:500; }
+.heavy-quality-results { display:grid; gap:6px; margin-top:12px; }
+.heavy-result-row { display:flex; justify-content:space-between; gap:12px; align-items:baseline; padding:7px 10px; border-radius:10px; background:rgba(120,140,140,.08); font-size:12px; }
+.heavy-result-row strong { flex:none; }
+.heavy-result-row span { text-align:right; color:var(--muted); }
 .primary-control-zone {
   display: grid;
   grid-template-rows: auto minmax(0, 1fr);
@@ -977,6 +1031,37 @@ body[data-telemetry-stale="true"] #battery-fill { opacity:.35; }
   border-bottom: 1.5px solid #c8cec6;
 }
 
+.console-modal {
+  width: min(1040px, calc(100vw - 64px));
+  max-width: 1040px;
+}
+.console-split { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin-top:14px; min-width:0; }
+.console-split section { min-width:0; }
+.console-split header { display:flex; align-items:center; gap:7px; margin:0 2px 7px; }
+.console-split header i { width:7px; height:7px; border-radius:50%; flex:0 0 auto; }
+.console-split header .rx-dot { background:#79c8eb; }
+.console-split header .tx-dot { background:#bce96c; }
+.console-split header span { color:#303836; font-size:12px; font-weight:600; }
+.console-split header small { margin-left:auto; color:#7d8683; font-size:10px; }
+.console-split pre {
+  height: min(55vh, 480px);
+  margin: 0;
+  padding: 14px;
+  overflow: auto;
+  border: 1px solid #d9ddda;
+  border-radius: 12px;
+  background: #171b1d;
+  color: #dce4e1;
+  font: 11px/1.45 Consolas, "SFMono-Regular", monospace;
+  white-space: pre-wrap;
+  overflow-wrap: anywhere;
+  user-select: text;
+}
+@media (max-width: 760px) {
+  .console-split { grid-template-columns:1fr; }
+  .console-split pre { height:220px; }
+}
+
 /* ── Toast ── */
 .toast {
   position: fixed;
@@ -1131,3 +1216,85 @@ body:not([data-controls-enabled="true"]) .controls-grid { opacity:.65; }
   .telemetry-zone { gap:12px; }
   .activity-history { gap:4px; }
 }
+
+/* Settings windows: readable fields, predictable spacing, one action hierarchy. */
+.modal {
+  color-scheme: light;
+  width: min(560px, calc(100vw - 32px));
+  max-height: calc(100dvh - 32px);
+  padding: 28px;
+  overflow: auto;
+  overscroll-behavior: contain;
+  border: 1px solid #dedfdf;
+  border-radius: 20px;
+  background: #f6f6f6;
+  box-shadow: 0 24px 80px rgba(0,0,0,.24);
+  backdrop-filter: none;
+}
+.modal[open] { animation: dialog-in .16s ease-out; }
+.modal.closing { animation: dialog-out .12s ease-in forwards; }
+.modal::backdrop { background: rgba(15,19,22,.4); backdrop-filter: blur(3px); }
+.modal > small { display:block; color:#73787b; font-size:12px; font-weight:400; margin:0 42px 6px 0; }
+.modal h2 { margin:0 40px 18px 0; font-size:28px; letter-spacing:-.025em; font-weight:400; }
+.modal h3 { margin:0 0 10px; font-size:14px; font-weight:500; color:#454b4e; }
+.modal .note { font-size:13px; line-height:1.5; margin:8px 0 0; color:#676e71; }
+.modal-close { top:16px; right:16px; width:36px; height:36px; display:grid; place-items:center; border-radius:50%; background:#e9ebec; color:#555c60; font-size:25px; line-height:1; }
+.modal-close:hover { background:#dfe3e5; }
+.settings-section { margin-top:22px; }
+.settings-section + .settings-section { border-top:1px solid #e0e3e4; padding-top:20px; }
+.modal .form-grid { gap:16px; margin-top:10px; }
+.modal .form-grid.two { grid-template-columns:repeat(2,minmax(0,1fr)); }
+.modal label { min-width:0; font-size:13px; line-height:1.35; font-weight:400; color:#50585c; }
+.modal label > span { display:block; margin-bottom:7px; }
+.modal input,.modal select { width:100%; min-width:0; height:42px; padding:0 13px; border:1px solid #d7dcde; border-radius:999px; background:#fff; color:#272c2f; font-size:14px; font-weight:400; }
+.modal select { padding-right:28px; }
+.modal :is(button,input,select,summary,pre):focus-visible { outline:2px solid #6598b5; outline-offset:3px; }
+.modal .number-pill { height:42px; grid-template-columns:36px minmax(0,1fr) 36px; background:#fff; border:1px solid #d7dcde; }
+.modal .number-pill button { width:36px; height:40px; font-size:24px; color:#5b666b; }
+.modal .number-pill input { border:0; padding:0; height:40px; appearance:textfield; -moz-appearance:textfield; }
+.modal .number-pill input::-webkit-inner-spin-button { appearance:none; }
+.modal .number-pill:focus-within { border-color:#6598b5; }
+.custom-port-label { display:block; margin-top:16px; }
+.custom-port-row { display:flex; gap:8px; }
+.custom-port-row input { flex:1; }
+.modal .button { min-height:42px; height:auto; padding:10px 18px; font-size:14px; font-weight:400; border-radius:999px; white-space:normal; }
+.modal .button.subtle { background:#e9ebec; border:0; color:#424b50; }
+.modal .modal-primary { background:#333e44; color:#fff; border:0; }
+.modal .modal-primary:hover { background:#455660; }
+.modal .modal-actions { margin-top:24px; gap:10px; align-items:center; }
+.modal .form-feedback { margin:16px 0 0; padding:10px 12px; border-radius:12px; font-size:13px; line-height:1.5; color:#9b392e; background:#f5e6e3; }
+.modal [hidden] { display:none !important; }
+.modal [data-busy="true"] { cursor:progress; }
+.motor-modal { width:min(650px,calc(100vw - 32px)); }
+.modal .motor-head,.modal .motor-row { grid-template-columns:78px minmax(100px,1fr) 94px 86px; font-size:13px; gap:10px; padding:10px 0; }
+.modal .motor-head { margin-top:18px; color:#727b80; font-size:12px; font-weight:400; }
+.motor-row strong { font-size:12px; font-weight:500; }
+.motor-row > span { font-size:12px; color:#727b80; }
+.modal .motor-row .button { min-height:36px; font-size:12px; padding:8px 12px; }
+.motor-other { margin-top:16px; }
+.motor-other summary { cursor:pointer; padding:12px 0; color:#697278; font-size:13px; }
+.quality-summary { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:10px; margin-top:18px; }
+.quality-summary div { border-radius:14px; background:#e9ebec; padding:14px 12px; min-width:0; }
+.quality-summary span { display:block; font-size:12px; color:#697278; margin-bottom:8px; }
+.quality-summary strong { font-size:20px; font-weight:400; font-variant-numeric:tabular-nums; }
+.modal .heavy-quality-status { padding:12px; background:#e9ebec; border-radius:12px; font-size:14px; margin-top:14px; }
+.modal .heavy-result-row { font-size:13px; padding:10px 12px; font-variant-numeric:tabular-nums; }
+.console-modal { width:min(1020px,calc(100vw - 32px)); }
+.console-toolbar { display:flex; justify-content:space-between; align-items:center; gap:12px; }
+.console-toolbar .note { margin:0; }
+.modal .console-split header small { font-size:12px; }
+.modal .console-split pre { height:clamp(180px,48vh,430px); padding:14px; font-size:12px; line-height:1.55; border-radius:12px; }
+@keyframes dialog-in { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
+@keyframes dialog-out { to { opacity:0; transform:translateY(5px); } }
+@media (max-width:520px) {
+  .modal { padding:22px 18px; }
+  .modal .form-grid.two { grid-template-columns:1fr; }
+  .modal .motor-head,.modal .motor-row { grid-template-columns:56px minmax(80px,1fr) 74px 66px; gap:5px; font-size:12px; }
+  .modal .motor-row .button { padding:8px 6px; }
+  .quality-summary { gap:6px; }
+  .quality-summary div { padding:12px 8px; }
+  .quality-summary strong { font-size:17px; }
+}
+@media (prefers-reduced-motion:reduce) {
+  .modal[open],.modal.closing { animation:none; }
+}

SUB Control/web_ui.py

@@ -40,12 +40,15 @@ class ControlApi:
             "app_state": "disconnected",
             "status": "Ready. Select a USB port to begin.",
             "battery": None,
+            "link_quality": None,
+            "heavy_quality": None,
             "log_path": None,
             "servos": {str(i): {"function": None, "direction": None} for i in range(1, 17)},
         }
         self.servo_functions: dict[int, int] = {}
         self.motor_directions: dict[int, int] = {}
         self.battery_path = Path(__file__).resolve().parent / "battery_settings.json"
+        self.link_path = Path(__file__).resolve().parent / "link_settings.json"
         self.model_path = Path(__file__).resolve().parent / "model_settings.json"
         self.model_cache = Path(__file__).resolve().parent / "runtime" / "vehicle_model.stl"
         self.model_cache_name = Path(__file__).resolve().parent / "runtime" / "vehicle_model_name.txt"
@@ -62,11 +65,22 @@ class ControlApi:
             self.battery_config.update(json.loads(self.battery_path.read_text(encoding="utf-8")))
         except (OSError, ValueError, TypeError):
             pass
+        self.link_config = {
+            "baud": 57600, "control_hz": 20,
+            "ping_hz": 1, "system_hz": 1, "servo_hz": 2,
+            "rc_hz": 2, "esc_hz": 1,
+        }
+        try:
+            self.link_config.update(json.loads(self.link_path.read_text(encoding="utf-8")))
+        except (OSError, ValueError, TypeError):
+            pass
+        self._apply_link_config()
 
     def initial_state(self):
         return {
             "ports": self.refresh_ports(),
             "battery_config": self.battery_config,
+            "link_config": self.link_config,
             "state": self._snapshot(),
             "model_info": self.get_saved_model_info(),
         }
@@ -233,6 +247,9 @@ class ControlApi:
                 self.state.update(
                     connected=True, link="LINK OK", vehicle="DEMO • DISARMED",
                     armed=False, mode="MANUAL", status="Demo mode ready — no hardware connected.",
+                    link_quality={"grade": "excellent", "latency_ms": 12.0,
+                                  "loss_percent": 0.0, "samples": 20,
+                                  "corrupt_frames_20s": 0, "heartbeat_age_s": 0.1},
                     battery={"voltage": 15.8, "per_cell": 3.95, "percent": 72,
                              "cells": 4, "low": False},
                 )
@@ -268,15 +285,26 @@ class ControlApi:
         raise TimeoutError(f"No MAVLink heartbeat received from {port} within 8 seconds")
 
     def disconnect(self):
+        if self.worker.heavy_quality_test is not None:
+            self.worker.cancel_heavy_quality_test()
         if self.demo_mode:
             self.demo_mode = False
             with self.lock:
                 self.state.update(connected=False, link="DISCONNECTED", vehicle="No heartbeat",
-                                  armed=False, mode=None, battery=None, status="Demo mode disconnected")
+                                  armed=False, mode=None, battery=None, link_quality=None,
+                                  status="Demo mode disconnected")
             return True
         self.worker.disconnect()
         return True
 
+    def start_heavy_quality_test(self):
+        if self.demo_mode:
+            raise RuntimeError("The heavy link test requires a real flight-controller connection")
+        return self.worker.start_heavy_quality_test()
+
+    def cancel_heavy_quality_test(self):
+        return self.worker.cancel_heavy_quality_test()
+
     def set_axes(self, forward, turn, vertical, sequence=None):
         if self.demo_mode:
             with self.lock:
@@ -389,8 +417,33 @@ class ControlApi:
             raise ValueError("Full voltage per cell must be greater than empty voltage")
         if not 0 <= clean["warning_percent"] <= 100:
             raise ValueError("Warning percentage must be between 0 and 100")
-        self.battery_config = clean
         self.battery_path.write_text(json.dumps(clean, indent=2) + "\n", encoding="utf-8")
+        self.battery_config = clean
+        return clean
+
+    def _apply_link_config(self):
+        self.worker.rate_hz = self.link_config["control_hz"]
+        self.worker.set_link_rates(self.link_config["ping_hz"], {
+            "SYS_STATUS": self.link_config["system_hz"],
+            "SERVO_OUTPUT_RAW": self.link_config["servo_hz"],
+            "RC_CHANNELS": self.link_config["rc_hz"],
+            "ESC_TELEMETRY_1_TO_4": self.link_config["esc_hz"],
+        })
+
+    def save_link_settings(self, config):
+        allowed = {0, 1, 2, 5, 10}
+        clean = {key: int(config.get(key, value)) for key, value in self.link_config.items()}
+        if clean["baud"] not in {9600, 19200, 38400, 57600, 115200}:
+            raise ValueError("Choose a supported baud rate")
+        if clean["control_hz"] not in {10, 20}:
+            raise ValueError("Control rate must be 10 or 20 Hz")
+        if clean["ping_hz"] not in {1, 2, 5, 10}:
+            raise ValueError("Link test rate must be 1, 2, 5 or 10 Hz")
+        if any(clean[key] not in allowed for key in ("system_hz", "servo_hz", "rc_hz", "esc_hz")):
+            raise ValueError("Telemetry rates must be Off, 1, 2, 5 or 10 Hz")
+        self.link_path.write_text(json.dumps(clean, indent=2) + "\n", encoding="utf-8")
+        self.link_config = clean
+        self._apply_link_config()
         return clean
 
     def open_logs(self):
@@ -399,6 +452,10 @@ class ControlApi:
         os.startfile(path)
         return True
 
+    def read_console(self, limit=150):
+        """Return a bounded, read-only view of the local session console."""
+        return self.worker.read_console(limit)
+
     def poll(self):
         # Bound a poll even if telemetry arrives continuously.
         with self._poll_lock:
@@ -468,6 +525,10 @@ class ControlApi:
                     "voltage": voltage, "per_cell": per_cell, "percent": percent,
                     "cells": cells, "low": percent <= self.battery_config["warning_percent"],
                 }
+            elif kind == "link_quality":
+                self.state["link_quality"] = event[1]
+            elif kind == "heavy_quality":
+                self.state["heavy_quality"] = event[1]
             elif kind == "servo_param":
                 _, param_id, value = event
                 servo = int(param_id[5:param_id.index("_")])
@@ -490,7 +551,7 @@ class ControlApi:
                 last_err = self.state.get("last_error")
                 status_msg = last_err if last_err else "Disconnected"
                 self.state.update(connected=False, link="DISCONNECTED", vehicle="No heartbeat",
-                                  mode=None, status=status_msg)
+                                  mode=None, link_quality=None, status=status_msg)
                 self.state["last_error"] = None
 
     def _update_servo(self, servo):

app.py

@@ -13,6 +13,9 @@ from datetime import datetime
 from pathlib import Path
 from tkinter import messagebox, ttk
 
+# ESC_TELEMETRY_1_TO_4 uses a MAVLink 2 message ID. Select the v2 dialect
+# before importing pymavlink so received ESC packets can be decoded/logged.
+os.environ["MAVLINK20"] = "1"
 from pymavlink import mavutil
 from serial.tools import list_ports
 
@@ -67,6 +70,10 @@ class MavlinkWorker:
         self.connection = None
         self.stop_event = threading.Event()
         self.lock = threading.Lock()
+        # pymavlink writes are not thread-safe. The web/API thread can issue
+        # commands while this worker sends heartbeats and controls, so serialize
+        # every packet before it reaches a low-bandwidth serial link.
+        self.tx_lock = threading.Lock()
         self.thread = None
         self.axes = Axes()
         self.output_axes = Axes()
@@ -87,6 +94,34 @@ class MavlinkWorker:
         self.last_rx = 0.0
         self.armed = False
         self.config_paused = False
+        # Keep configuration traffic off the link during an arm/disarm
+        # transition, including the wait for the vehicle's confirmation.
+        self.command_quiet_until = 0.0
+        self.disarm_requested_until = 0.0
+        self.pending_arm_state = None
+        self.next_arm_retry_at = 0.0
+        self.arm_retry_deadline = 0.0
+        self.arm_confirmation = 0
+        self.stream_config = deque()
+        self.next_stream_config_at = 0.0
+        # Low-rate TIMESYNC echoes measure PC↔FC round trips with minimal traffic.
+        self.ping_rate_hz = 1
+        self.heavy_quality_test = None
+        self.heavy_pending_pings = {}
+        self.heavy_quality_latest = None
+        self.telemetry_rates_hz = {
+            "SYS_STATUS": 1, "SERVO_OUTPUT_RAW": 2,
+            "RC_CHANNELS": 2, "ESC_TELEMETRY_1_TO_4": 1,
+        }
+        self.ping_sequence = 0
+        self.next_ping_at = 0.0
+        self.pending_pings = {}
+        self.ping_results = deque(maxlen=300)
+        self.bad_frame_times = deque()
+        self.bad_frame_bytes = deque()
+        self.rx_sequence_by_source = {}
+        self.rx_delivery_results = deque(maxlen=1024)
+        self.next_quality_publish_at = 0.0
         self.param_scan = deque()
         self.param_waiting = None
         self.param_deadline = 0.0
@@ -96,6 +131,9 @@ class MavlinkWorker:
         self.log_lock = threading.Lock()
         self.log_file = None
         self.log_path = None
+        self.console_lines = deque(maxlen=500)
+        self.console_rx_lines = deque(maxlen=300)
+        self.console_tx_lines = deque(maxlen=300)
 
     def connect(self, port: str, baud: int):
         print(f"[MavlinkWorker] connect() called: port={port!r}, baud={baud}")
@@ -109,8 +147,12 @@ class MavlinkWorker:
         self.log_file = self.log_path.open("a", encoding="utf-8", buffering=1)
         normalized = normalize_endpoint(port)
         print(f"[MavlinkWorker] normalized endpoint: {normalized!r}")
-        self.log("SESSION", f"start port={normalized} (input={port}) baud={baud} control_hz={self.rate_hz}")
+        self.log("SESSION", f"start port={normalized} (input={port}) baud={baud} "
+                 f"control_hz={self.rate_hz} rx=MAVLink2 tx=MAVLink2")
         self.events.put(("log_path", str(self.log_path)))
+        self.last_heartbeat = 0.0
+        self.last_rx = 0.0
+        self.next_quality_publish_at = 0.0
         self.thread = threading.Thread(
             target=self._run, args=(normalized, baud), daemon=True
         )
@@ -137,7 +179,7 @@ class MavlinkWorker:
 
             # Send initial GCS heartbeat immediately
             self.log("TX_HEARTBEAT", "GCS initial")
-            conn.mav.heartbeat_send(
+            self._send_mav(conn, "heartbeat_send",
                 mavutil.mavlink.MAV_TYPE_GCS,
                 mavutil.mavlink.MAV_AUTOPILOT_INVALID,
                 0, 0, mavutil.mavlink.MAV_STATE_ACTIVE,
@@ -149,17 +191,32 @@ class MavlinkWorker:
                 now = time.monotonic()
                 if now >= next_gcs_hb:
                     self.log("TX_HEARTBEAT", "GCS")
-                    conn.mav.heartbeat_send(
+                    self._send_mav(conn, "heartbeat_send",
                         mavutil.mavlink.MAV_TYPE_GCS,
                         mavutil.mavlink.MAV_AUTOPILOT_INVALID,
                         0, 0, mavutil.mavlink.MAV_STATE_ACTIVE,
                     )
                     next_gcs_hb = now + 1.0
-                if self.target_system and now >= next_control:
+                # ArduSub cannot use MANUAL_CONTROL while disarmed. Keeping a
+                # 20 Hz neutral stream alive here only competes with ARM and
+                # its acknowledgement on constrained links.
+                if self.target_system and self.armed and now >= next_control:
                     self._send_control()
-                    next_control = now + (1.0 / max(1, self.rate_hz))
+                    # The first disarm packet is preceded by a neutral command.
+                    # Until disarm is confirmed, keep sending neutral at a
+                    # lower rate instead of consuming 20 Hz on the weak link.
+                    control_hz = min(self.rate_hz, 5) if now < self.disarm_requested_until else self.rate_hz
+                    next_control = now + (1.0 / max(1, control_hz))
+                elif not self.armed:
+                    next_control = now
                 if self.target_system:
+                    self._tick_arm_retry(now)
+                    self._tick_link_probe(now)
+                    self._tick_stream_config(now)
                     self._tick_param_scan(now)
+                if now >= self.next_quality_publish_at:
+                    self._publish_link_quality()
+                    self.next_quality_publish_at = now + 1.0
 
                 msg = conn.recv_match(blocking=False)
                 if msg:
@@ -170,6 +227,8 @@ class MavlinkWorker:
             print(f"[MavlinkWorker._run] EXCEPTION: {exc}")
             self.events.put(("error", f"Connection error: {exc}"))
         finally:
+            if self.heavy_quality_test is not None:
+                self.cancel_heavy_quality_test()
             self._safe_stop()
             if self.connection:
                 try:
@@ -180,6 +239,19 @@ class MavlinkWorker:
             self.target_system = 0
             self.armed = False
             self.config_paused = False
+            self.command_quiet_until = 0.0
+            self.disarm_requested_until = 0.0
+            self.pending_arm_state = None
+            self.next_arm_retry_at = 0.0
+            self.arm_retry_deadline = 0.0
+            self.arm_confirmation = 0
+            self.stream_config.clear()
+            self.pending_pings.clear()
+            self.ping_results.clear()
+            self.bad_frame_times.clear()
+            self.bad_frame_bytes.clear()
+            self.rx_sequence_by_source.clear()
+            self.rx_delivery_results.clear()
             self.log("SESSION", "disconnected")
             with self.log_lock:
                 if self.log_file:
@@ -189,22 +261,71 @@ class MavlinkWorker:
 
     def log(self, category: str, message: str):
         timestamp = datetime.now().astimezone().isoformat(timespec="milliseconds")
+        line = f"{timestamp} [{category}] {message}"
         with self.log_lock:
+            self.console_lines.append(line[:2000])
+            if category.startswith("RX") or category == "ONBOARD_LOG_ERROR":
+                self.console_rx_lines.append(line[:2000])
+            elif category.startswith("TX") or category == "OPERATOR":
+                self.console_tx_lines.append(line[:2000])
             if self.log_file:
-                self.log_file.write(f"{timestamp} [{category}] {message}\n")
+                self.log_file.write(line + "\n")
+
+    def read_console(self, limit=150):
+        with self.log_lock:
+            limit = max(1, min(300, int(limit)))
+            return {
+                "rx": list(self.console_rx_lines)[-limit:],
+                "tx": list(self.console_tx_lines)[-limit:],
+            }
+
+    def _send_mav(self, connection, method: str, *args):
+        """Serialize MAVLink 2 writes and protect the start of each burst."""
+        with self.tx_lock:
+            # This full-duplex module pair loses the opening bytes of some
+            # PC-to-FC bursts after the line has been idle. Put a valid,
+            # expendable GCS heartbeat first so the following packet remains
+            # intact and the FC also sees a healthy GCS heartbeat stream.
+            if method != "heartbeat_send" and hasattr(connection.mav, "heartbeat_send"):
+                connection.mav.heartbeat_send(
+                    mavutil.mavlink.MAV_TYPE_GCS,
+                    mavutil.mavlink.MAV_AUTOPILOT_INVALID,
+                    0, 0, mavutil.mavlink.MAV_STATE_ACTIVE,
+                )
+            getattr(connection.mav, method)(*args)
 
     def _handle_message(self, msg):
         msg_type = msg.get_type()
         if msg_type == "BAD_DATA":
+            now = time.monotonic()
+            self.bad_frame_times.append(now)
+            self.bad_frame_bytes.append((now, len(getattr(msg, "data", b""))))
+            self._trim_bad_frames(now)
             self.log("RX_BAD_DATA", repr(getattr(msg, "data", b"")))
             return
         self.last_rx = time.monotonic()
+        self._track_rx_delivery(msg)
         try:
             payload = json.dumps(msg.to_dict(), default=str, separators=(",", ":"))
         except Exception:
             payload = str(msg)
         self.log("RX", payload)
-        if msg_type == "HEARTBEAT" and getattr(msg, "type", 0) != mavutil.mavlink.MAV_TYPE_GCS:
+        if msg_type == "TIMESYNC" and int(getattr(msg, "tc1", 0)) != 0:
+            token = int(getattr(msg, "ts1", -1))
+            heavy_probe = self.heavy_pending_pings.pop(token, None)
+            if heavy_probe is not None:
+                stage_index, sent_at = heavy_probe
+                self._record_heavy_probe(stage_index, (time.monotonic() - sent_at) * 1000.0)
+                self._publish_heavy_quality()
+                sent_at = None
+            else:
+                sent_at = self.pending_pings.pop(token, None)
+            if sent_at is not None:
+                rtt_ms = (time.monotonic() - sent_at) * 1000.0
+                self.ping_results.append((time.monotonic(), rtt_ms))
+                self.log("RX_LINK_PROBE", f"timesync={token} rtt_ms={rtt_ms:.1f}")
+                self._publish_link_quality()
+        elif msg_type == "HEARTBEAT" and getattr(msg, "type", 0) != mavutil.mavlink.MAV_TYPE_GCS:
             if getattr(msg, "autopilot", mavutil.mavlink.MAV_AUTOPILOT_INVALID) == mavutil.mavlink.MAV_AUTOPILOT_INVALID:
                 return
             if self.target_system and (msg.get_srcSystem(), msg.get_srcComponent()) != (self.target_system, self.target_component):
@@ -216,6 +337,10 @@ class MavlinkWorker:
             armed = bool(msg.base_mode & mavutil.mavlink.MAV_MODE_FLAG_SAFETY_ARMED)
             self.armed = armed
             self.config_paused = armed
+            if self.pending_arm_state is not None and armed == self.pending_arm_state:
+                self.pending_arm_state = None
+            if not armed:
+                self.disarm_requested_until = 0.0
             try:
                 mode = mavutil.mode_string_v10(msg)
             except Exception:
@@ -224,6 +349,7 @@ class MavlinkWorker:
             ap_name = autopilot.name if autopilot else str(msg.autopilot)
             self.events.put(("heartbeat", self.target_system, ap_name, mode, armed, self.last_heartbeat))
             if first:
+                self.next_ping_at = time.monotonic()
                 self.events.put(("status", "Heartbeat received; controls are neutral."))
                 self._configure_low_bandwidth_streams()
                 self._start_servo_scan()
@@ -232,12 +358,21 @@ class MavlinkWorker:
                 return
             result = mavutil.mavlink.enums["MAV_RESULT"].get(msg.result)
             result_name = result.name if result else str(msg.result)
+            if int(msg.command) == mavutil.mavlink.MAV_CMD_SET_MESSAGE_INTERVAL:
+                self.log("RX_STREAM_CONFIG_ACK", result_name)
+                return
+            if (int(msg.command) == mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM
+                    and result_name not in ("MAV_RESULT_ACCEPTED", "MAV_RESULT_IN_PROGRESS")):
+                self.pending_arm_state = None
             self.events.put(("ack", int(msg.command), result_name, self.last_rx))
         elif msg_type == "STATUSTEXT":
             text = msg.text
             if isinstance(text, bytes):
                 text = text.decode(errors="replace")
-            self.events.put(("statustext", text.rstrip("\x00")))
+            text = text.rstrip("\x00")
+            if "/APM/LOGS" in text and "Failed" in text:
+                self.log("ONBOARD_LOG_ERROR", text)
+            self.events.put(("statustext", text))
         elif msg_type == "SYS_STATUS":
             voltage_mv = int(msg.voltage_battery)
             if 0 < voltage_mv < 65535:
@@ -264,6 +399,239 @@ class MavlinkWorker:
                     self.events.put(("motor_direction", int(parts[1]),
                                      int(round(msg.param_value))))
 
+    def _trim_bad_frames(self, now):
+        while self.bad_frame_times and now - self.bad_frame_times[0] > 20.0:
+            self.bad_frame_times.popleft()
+
+    def _track_rx_delivery(self, msg):
+        """Estimate downlink loss from MAVLink's per-source packet sequence."""
+        try:
+            source = (int(msg.get_srcSystem()), int(msg.get_srcComponent()))
+            sequence = int(msg.get_seq())
+        except (AttributeError, TypeError, ValueError):
+            return
+        if self.target_system and source != (self.target_system, self.target_component):
+            return
+        previous = self.rx_sequence_by_source.get(source)
+        self.rx_sequence_by_source[source] = sequence
+        if previous is None:
+            return
+        missing = (sequence - previous - 1) & 0xFF
+        # A large backwards jump is a reset/reordered packet, not 200 losses.
+        if missing > 127:
+            return
+        timestamp = time.monotonic()
+        self.rx_delivery_results.extend((timestamp, False) for _ in range(missing))
+        self.rx_delivery_results.append((timestamp, True))
+
+    def _publish_link_quality(self):
+        now = time.monotonic()
+        self._trim_bad_frames(now)
+        while self.ping_results and now - self.ping_results[0][0] > 30.0:
+            self.ping_results.popleft()
+        while self.rx_delivery_results and now - self.rx_delivery_results[0][0] > 30.0:
+            self.rx_delivery_results.popleft()
+        while self.bad_frame_bytes and now - self.bad_frame_bytes[0][0] > 20.0:
+            self.bad_frame_bytes.popleft()
+        samples = [sample for _, sample in self.ping_results]
+        received = [sample for sample in samples if sample is not None]
+        total = len(samples)
+        loss_percent = 100.0 * (total - len(received)) / total if total else None
+        ordered_rtt = sorted(received)
+        latency_ms = (sum(ordered_rtt) / len(ordered_rtt)) if ordered_rtt else None
+        median_rtt_ms = ordered_rtt[len(ordered_rtt) // 2] if ordered_rtt else None
+        p95_rtt_ms = ordered_rtt[min(len(ordered_rtt) - 1, (len(ordered_rtt) * 95 + 99) // 100 - 1)] if ordered_rtt else None
+        rx_received = sum(1 for _, delivered in self.rx_delivery_results if delivered)
+        rx_missing = sum(1 for _, delivered in self.rx_delivery_results if not delivered)
+        rx_loss_percent = 100.0 * rx_missing / (rx_received + rx_missing) if rx_received else None
+        rx_corrupt_bytes = sum(byte_count for _, byte_count in self.bad_frame_bytes)
+        heartbeat_age = (now - self.last_heartbeat) if self.last_heartbeat else None
+        if total < 10 or rx_received < 10 or heartbeat_age is None:
+            grade = "testing"
+        elif (heartbeat_age > 3 or loss_percent > 15
+              or (rx_loss_percent is not None and rx_loss_percent > 5)
+              or len(self.bad_frame_bytes) >= 5):
+            grade = "poor"
+        elif (loss_percent > 3 or (rx_loss_percent is not None and rx_loss_percent > 1)
+              or (p95_rtt_ms is not None and p95_rtt_ms > 500) or self.bad_frame_bytes):
+            grade = "fair"
+        elif (loss_percent > 0.5 or (rx_loss_percent is not None and rx_loss_percent > 0.2)
+              or (p95_rtt_ms is not None and p95_rtt_ms > 200)):
+            grade = "good"
+        else:
+            grade = "excellent"
+        self.events.put(("link_quality", {
+            "grade": grade,
+            "latency_ms": round(latency_ms, 1) if latency_ms is not None else None,
+            "rtt_median_ms": round(median_rtt_ms, 1) if median_rtt_ms is not None else None,
+            "rtt_p95_ms": round(p95_rtt_ms, 1) if p95_rtt_ms is not None else None,
+            "loss_percent": round(loss_percent, 1) if loss_percent is not None else None,
+            "probe_loss_percent": round(loss_percent, 1) if loss_percent is not None else None,
+            "probe_samples": total,
+            "probe_replies": len(received),
+            "rx_packets_30s": rx_received,
+            "rx_sequence_loss_percent": round(rx_loss_percent, 1) if rx_loss_percent is not None else None,
+            "rx_corrupt_frames_20s": len(self.bad_frame_bytes),
+            "rx_corrupt_bytes_20s": rx_corrupt_bytes,
+            "samples": total,
+            "corrupt_frames_20s": len(self.bad_frame_times),
+            "heartbeat_age_s": round(heartbeat_age, 1) if heartbeat_age is not None else None,
+            "probe_supported": total > 0,
+        }))
+
+    def _tick_link_probe(self, now):
+        if self.heavy_quality_test is not None:
+            self._tick_heavy_quality(now)
+            return
+        expired = [sequence for sequence, sent_at in self.pending_pings.items()
+                   if now - sent_at >= 2.5]
+        for sequence in expired:
+            self.pending_pings.pop(sequence, None)
+            self.ping_results.append((now, None))
+            self.log("LINK_PROBE_TIMEOUT", f"timesync={sequence}")
+        if expired:
+            self._publish_link_quality()
+        if (now < self.next_ping_at or now < self.command_quiet_until
+                or not self.connection or not self.target_system):
+            return
+        token = time.monotonic_ns()
+        self.pending_pings[token] = now
+        self.log("TX_LINK_PROBE", f"timesync={token}")
+        # ArduPilot implements TIMESYNC even on builds that omit PING. A
+        # request has tc1=0; the response mirrors our unique ts1 token.
+        self._send_mav(self.connection, "timesync_send", 0, token)
+        self.next_ping_at = now + (1.0 / max(1, self.ping_rate_hz))
+
+    def start_heavy_quality_test(self):
+        if not self.connection or not self.target_system:
+            raise RuntimeError("Connect to the flight controller before testing the link")
+        if self.armed:
+            raise RuntimeError("The heavy link test is available while the vehicle is disarmed")
+        if self.pending_arm_state is not None or time.monotonic() < self.command_quiet_until:
+            raise RuntimeError("Wait for the current vehicle command to finish")
+        if self.heavy_quality_test is not None:
+            raise RuntimeError("A heavy link test is already running")
+        self.pending_pings.clear()
+        self.heavy_pending_pings.clear()
+        self.heavy_quality_latest = {
+            "running": True, "stage": 1, "stages": 3, "rate_hz": 1,
+            "status": "Running", "results": [],
+        }
+        self.heavy_quality_test = {
+            "rates": (1, 5, 10), "duration_s": 10.0, "stage_index": 0,
+            "stage_started": time.monotonic(), "next_probe_at": time.monotonic(),
+            "stages": [{"rate_hz": rate, "sent": 0, "replies": 0,
+                        "timeouts": 0, "rtts": []} for rate in (1, 5, 10)],
+        }
+        self.log("TX_HEAVY_TEST", "started rates=1,5,10Hz stage_seconds=10")
+        self._publish_heavy_quality()
+        return self.heavy_quality_latest
+
+    def cancel_heavy_quality_test(self):
+        if self.heavy_quality_test is None:
+            return self.heavy_quality_latest
+        self.heavy_pending_pings.clear()
+        test = self.heavy_quality_test
+        self.heavy_quality_test = None
+        self.heavy_quality_latest = {
+            "running": False, "stage": 0, "stages": len(test["rates"]),
+            "rate_hz": None, "status": "Cancelled", "results": self._heavy_results(test),
+        }
+        self.next_ping_at = time.monotonic()
+        self.log("TX_HEAVY_TEST", "cancelled")
+        self.events.put(("heavy_quality", self.heavy_quality_latest))
+        return self.heavy_quality_latest
+
+    @staticmethod
+    def _heavy_results(test):
+        results = []
+        for stage in test["stages"]:
+            rtts = sorted(stage["rtts"])
+            sent = stage["sent"]
+            replies = stage["replies"]
+            resolved = replies + stage["timeouts"]
+            results.append({
+                "rate_hz": stage["rate_hz"], "sent": sent, "replies": replies,
+                "loss_percent": round(100.0 * stage["timeouts"] / resolved, 1) if resolved else None,
+                "median_rtt_ms": round(rtts[len(rtts) // 2], 1) if rtts else None,
+                "p95_rtt_ms": round(rtts[min(len(rtts) - 1, (len(rtts) * 95 + 99) // 100 - 1)], 1) if rtts else None,
+            })
+        return results
+
+    def _record_heavy_probe(self, stage_index, rtt_ms=None):
+        test = self.heavy_quality_test
+        if test is None or not 0 <= stage_index < len(test["stages"]):
+            return
+        stage = test["stages"][stage_index]
+        if rtt_ms is None:
+            stage["timeouts"] += 1
+        else:
+            stage["replies"] += 1
+            stage["rtts"].append(rtt_ms)
+
+    def _publish_heavy_quality(self):
+        test = self.heavy_quality_test
+        if test is None:
+            return
+        index = test["stage_index"]
+        stage = test["stages"][index]
+        self.heavy_quality_latest = {
+            "running": True, "stage": index + 1, "stages": len(test["rates"]),
+            "rate_hz": stage["rate_hz"], "sent": stage["sent"],
+            "replies": stage["replies"], "timeouts": stage["timeouts"],
+            "status": f"Stage {index + 1} of {len(test['rates'])}: {stage['rate_hz']} Hz",
+            "results": self._heavy_results(test),
+        }
+        self.events.put(("heavy_quality", self.heavy_quality_latest))
+
+    def _tick_heavy_quality(self, now):
+        test = self.heavy_quality_test
+        if test is None:
+            return
+        for token, (stage_index, sent_at) in list(self.heavy_pending_pings.items()):
+            if now - sent_at >= 2.5:
+                self.heavy_pending_pings.pop(token, None)
+                self._record_heavy_probe(stage_index)
+                self.log("HEAVY_PROBE_TIMEOUT", f"rate={test['rates'][stage_index]}Hz timesync={token}")
+        index = test["stage_index"]
+        stage_pending = any(stage_index == index for stage_index, _ in self.heavy_pending_pings.values())
+        if now - test["stage_started"] >= test["duration_s"] and not stage_pending:
+            index += 1
+            if index >= len(test["rates"]):
+                results = self._heavy_results(test)
+                self.heavy_quality_test = None
+                self.heavy_quality_latest = {
+                    "running": False, "stage": 3, "stages": 3, "rate_hz": None,
+                    "status": "Complete", "results": results,
+                }
+                self.next_ping_at = now
+                self.log("TX_HEAVY_TEST", "complete")
+                self.events.put(("heavy_quality", self.heavy_quality_latest))
+                return
+            test["stage_index"] = index
+            test["stage_started"] = now
+            test["next_probe_at"] = now
+            self._publish_heavy_quality()
+        index = test["stage_index"]
+        stage = test["stages"][index]
+        if now >= test["next_probe_at"] and now - test["stage_started"] < test["duration_s"]:
+            token = time.monotonic_ns()
+            self.heavy_pending_pings[token] = (index, now)
+            stage["sent"] += 1
+            self.log("TX_HEAVY_PROBE", f"rate={stage['rate_hz']}Hz timesync={token}")
+            self._send_mav(self.connection, "timesync_send", 0, token)
+            test["next_probe_at"] = now + 1.0 / stage["rate_hz"]
+        if now >= self.next_quality_publish_at:
+            self._publish_heavy_quality()
+            self.next_quality_publish_at = now + 1.0
+
+    def set_link_rates(self, ping_hz, telemetry_rates):
+        self.ping_rate_hz = max(1, min(10, int(ping_hz)))
+        for name in self.telemetry_rates_hz:
+            if name in telemetry_rates:
+                self.telemetry_rates_hz[name] = max(0, min(10, int(telemetry_rates[name])))
+        if self.connection and self.target_system:
+            self._configure_low_bandwidth_streams()
     def _start_servo_scan(self):
         names = [f"SERVO{number}_FUNCTION" for number in range(1, 17)]
         # ArduSub reverses mixer motors with MOT_n_DIRECTION (1 normal,
@@ -284,31 +652,52 @@ class MavlinkWorker:
         self.param_retries = 0
 
     def _configure_low_bandwidth_streams(self):
-        """Stop inherited high-rate streams and request only diagnostic essentials."""
+        """Pace optional telemetry changes; never burst them at arm time."""
         if not self.connection:
             return
         self.log("TX_STREAM_CONFIG", "stop MAV_DATA_STREAM_ALL")
-        self.connection.mav.request_data_stream_send(
+        self._send_mav(self.connection, "request_data_stream_send",
             self.target_system, self.target_component,
             mavutil.mavlink.MAV_DATA_STREAM_ALL, 0, 0,
         )
-        # Heartbeat and STATUSTEXT do not need to be requested. Keep only
+        # ATTITUDE and VFR_HUD interval commands were accepted by this FC.
-        # output/input evidence needed to diagnose controls, at 2 Hz each.
+        # AHRS2 is also unneeded, but an acknowledgement has not been seen.
-        for message_id, interval_us, name in (
+        # NAMED_VALUE_FLOAT explicitly returned DENIED, so do not retry it.
-            (mavutil.mavlink.MAVLINK_MSG_ID_SYS_STATUS, 1_000_000, "SYS_STATUS"),
+        # A single interval command is sometimes lost, so send two paced
-            (mavutil.mavlink.MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, 500_000, "SERVO_OUTPUT_RAW"),
+        # passes. This does not change persistent parameters or onboard logs.
-            (mavutil.mavlink.MAVLINK_MSG_ID_RC_CHANNELS, 500_000, "RC_CHANNELS"),
+        unwanted = (
-        ):
+            "ATTITUDE", "AHRS2", "VFR_HUD",
-            self.log("TX_STREAM_CONFIG", f"{name} interval_us={interval_us}")
+        )
-            self.connection.mav.command_long_send(
+        self.stream_config = deque(
-                self.target_system, self.target_component,
+            (name, getattr(mavutil.mavlink, f"MAVLINK_MSG_ID_{name}"), -1)
-                mavutil.mavlink.MAV_CMD_SET_MESSAGE_INTERVAL,
+            for _ in range(2) for name in unwanted
-                0, message_id, interval_us, 0, 0, 0, 0, 0,
+        )
-            )
+        for name, rate_hz in self.telemetry_rates_hz.items():
-        self.events.put(("status", "Low-bandwidth telemetry configured; reading servo setup…"))
+            interval_us = -1 if rate_hz == 0 else round(1_000_000 / rate_hz)
+            self.stream_config.append((
+                name, getattr(mavutil.mavlink, f"MAVLINK_MSG_ID_{name}"), interval_us,
+            ))
+        self.next_stream_config_at = time.monotonic()
+        self.events.put(("status", "Applying low-bandwidth telemetry rates…"))
+
+    def _tick_stream_config(self, now):
+        if (not self.connection or not self.target_system or self.armed
+                or now < self.command_quiet_until or now < self.next_stream_config_at
+                or not self.stream_config):
+            return
+        name, message_id, interval_us = self.stream_config.popleft()
+        self.log("TX_STREAM_CONFIG", f"{name} interval_us={interval_us}")
+        self._send_mav(self.connection, "command_long_send",
+            self.target_system, self.target_component,
+            mavutil.mavlink.MAV_CMD_SET_MESSAGE_INTERVAL,
+            0, message_id, interval_us, 0, 0, 0, 0, 0,
+        )
+        self.next_stream_config_at = now + 0.5
 
     def _tick_param_scan(self, now):
-        if not self.connection or self.config_paused or now < self.param_deadline:
+        if (not self.connection or self.config_paused
+                or self.stream_config or now < self.next_stream_config_at
+                or now < self.command_quiet_until or now < self.param_deadline):
             return
         if self.param_waiting is not None:
             if self.param_retries < 2:
@@ -329,7 +718,7 @@ class MavlinkWorker:
 
     def _request_param(self, name: str):
         self.log("TX_PARAM_REQUEST", name)
-        self.connection.mav.param_request_read_send(
+        self._send_mav(self.connection, "param_request_read_send",
             self.target_system, self.target_component, name.encode("ascii"), -1
         )
 
@@ -343,7 +732,7 @@ class MavlinkWorker:
             raise RuntimeError(f"{name} has not been read from the autopilot")
         self.pending_sets[name] = int(value)
         self.log("TX_PARAM_SET", f"{name}={value} type={param_type}")
-        self.connection.mav.param_set_send(
+        self._send_mav(self.connection, "param_set_send",
             self.target_system, self.target_component, name.encode("ascii"),
             float(value), param_type,
         )
@@ -396,7 +785,7 @@ class MavlinkWorker:
             f"x={x} y={y} z={z} r={r} active={active} "
             f"target=({target.forward:.3f},{target.lateral:.3f},{target.vertical:.3f},{target.yaw:.3f})",
         )
-        conn.mav.manual_control_send(self.target_system, x, y, z, r, 0)
+        self._send_mav(conn, "manual_control_send", self.target_system, x, y, z, r, 0)
 
     @staticmethod
     def _approach(current: float, target: float, max_change: float) -> float:
@@ -409,18 +798,45 @@ class MavlinkWorker:
         conn = self.connection
         if not conn or not self.target_system:
             raise RuntimeError("No autopilot heartbeat")
+        if arm and self.heavy_quality_test is not None:
+            self.cancel_heavy_quality_test()
+        now = time.monotonic()
+        self.command_quiet_until = now + 6.0
         if not arm:
+            self.disarm_requested_until = now + 6.0
             self._send_control(force_neutral=True)
         else:
             # Give the ARM request priority over the low-rate parameter scan.
             self.config_paused = True
         self.log("TX_COMMAND", "ARM" if arm else "DISARM")
-        conn.mav.command_long_send(
+        self.pending_arm_state = bool(arm)
+        self.next_arm_retry_at = now + 0.25
+        self.arm_retry_deadline = now + 5.0
+        self.arm_confirmation = 0
+        self._send_arm_packet(arm)
+
+    def _send_arm_packet(self, arm: bool):
+        conn = self.connection
+        if not conn or not self.target_system:
+            return
+        self._send_mav(conn, "command_long_send",
             self.target_system, self.target_component,
             mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
-            0, 1.0 if arm else 0.0, 0, 0, 0, 0, 0, 0,
+            self.arm_confirmation, 1.0 if arm else 0.0, 0, 0, 0, 0, 0, 0,
         )
 
+    def _tick_arm_retry(self, now):
+        if self.pending_arm_state is None or now < self.next_arm_retry_at:
+            return
+        if now >= self.arm_retry_deadline:
+            self.log("TX_COMMAND_TIMEOUT", "ARM" if self.pending_arm_state else "DISARM")
+            self.pending_arm_state = None
+            return
+        self.log("TX_COMMAND_RETRY", "ARM" if self.pending_arm_state else "DISARM")
+        self.arm_confirmation = min(255, self.arm_confirmation + 1)
+        self._send_arm_packet(self.pending_arm_state)
+        self.next_arm_retry_at = now + 0.25
+
     def set_manual_mode(self):
         conn = self.connection
         if not conn or not self.target_system:
@@ -430,7 +846,7 @@ class MavlinkWorker:
         if manual is None:
             raise RuntimeError("MANUAL mode is not advertised by this firmware")
         self.log("TX_MODE", f"MANUAL custom_mode={manual}")
-        conn.mav.set_mode_send(
+        self._send_mav(conn, "set_mode_send",
             self.target_system,
             mavutil.mavlink.MAV_MODE_FLAG_CUSTOM_MODE_ENABLED,
             manual,
@@ -467,7 +883,7 @@ class MavlinkWorker:
         if self.connection and self.target_system:
             try:
                 self._send_control(force_neutral=True)
-                self.connection.mav.command_long_send(
+                self._send_mav(self.connection, "command_long_send",
                     self.target_system, self.target_component,
                     mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
                     0, 0, 0, 0, 0, 0, 0, 0,

tests/test_vehicle_state.py

@@ -1,6 +1,9 @@
 """No serial port is opened by these tests."""
 import queue
+import threading
+import time
 import unittest
+from types import SimpleNamespace
 from unittest.mock import Mock, patch
 
 from app import Axes, MavlinkWorker, NEUTRAL_Z
@@ -100,9 +103,18 @@ class WorkerWatchdogTests(unittest.TestCase):
 
     def assertNeutral(self):
         self.worker._send_control()
-        self.assertEqual(self.worker.connection.mav.manual_control_send.call_args.args,
+        self.assertEqual(self.control_values(),
                          (1, 0, 0, NEUTRAL_Z, 0, 0))
 
+    def control_values(self):
+        return self.worker.connection.mav.manual_control_send.call_args.args
+
+    def test_manual_control_uses_native_v2_without_forced_long_payload(self):
+        self.worker._send_mav(self.worker.connection, 'manual_control_send',
+                              1, 50, 0, 525, -20, 0)
+        self.assertEqual(self.control_values(), (1, 50, 0, 525, -20, 0))
+        self.assertEqual(self.worker.connection.mav.manual_control_send.call_args.kwargs, {})
+
     def test_ui_freeze_neutralizes_and_does_not_replay(self):
         with patch("app.time.monotonic", return_value=10):
             self.worker.set_axes(Axes(forward=1), 1)
@@ -118,7 +130,7 @@ class WorkerWatchdogTests(unittest.TestCase):
             self.worker.set_axes(Axes(forward=.25, vertical=.25), 1)
             self.worker._send_control()
             # 25% input at the default 20% limit: 5% command, not 100%.
-            self.assertEqual(self.worker.connection.mav.manual_control_send.call_args.args,
+            self.assertEqual(self.control_values(),
                              (1, 50, 0, 525, 0, 0))
 
     def test_heartbeat_freeze_neutralizes_even_with_live_ui(self):
@@ -131,6 +143,160 @@ class WorkerWatchdogTests(unittest.TestCase):
         self.worker.set_axes(Axes(forward=1), 19)
         self.assertEqual(self.worker.axes, Axes())
 
+    def test_mavlink_transmissions_are_serialized(self):
+        first_entered = threading.Event()
+        release_first = threading.Event()
+        second_entered = threading.Event()
+
+        class Mav:
+            def first_send(self, **_):
+                first_entered.set()
+                release_first.wait(1)
+
+            def second_send(self, **_):
+                second_entered.set()
+
+        connection = SimpleNamespace(mav=Mav())
+        first = threading.Thread(target=self.worker._send_mav,
+                                 args=(connection, "first_send"))
+        second = threading.Thread(target=self.worker._send_mav,
+                                  args=(connection, "second_send"))
+        first.start()
+        self.assertTrue(first_entered.wait(.5))
+        second.start()
+        time.sleep(.05)
+        self.assertFalse(second_entered.is_set())
+        release_first.set()
+        first.join(1)
+        second.join(1)
+        self.assertTrue(second_entered.is_set())
+
+    def test_live_console_is_read_only_bounded_and_keeps_newest_lines(self):
+        for index in range(310):
+            self.worker.log("RX_TEST", f"vehicle {index}")
+            self.worker.log("TX_TEST", f"computer {index}")
+        sides = self.worker.read_console(2)
+        self.assertEqual(set(sides), {"rx", "tx"})
+        self.assertTrue(sides["rx"][0].endswith("[RX_TEST] vehicle 308"))
+        self.assertTrue(sides["rx"][1].endswith("[RX_TEST] vehicle 309"))
+        self.assertTrue(sides["tx"][1].endswith("[TX_TEST] computer 309"))
+        self.assertEqual(len(self.worker.console_rx_lines), 300)
+        self.assertEqual(len(self.worker.console_tx_lines), 300)
+        self.assertEqual(len(self.worker.console_lines), 500)
+
+    def test_arm_request_pauses_parameter_traffic(self):
+        self.worker.armed = False
+        self.worker.param_scan.append("SERVO1_FUNCTION")
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.command_arm(True)
+            self.worker.config_paused = False  # A disarmed heartbeat arrived.
+            self.worker._tick_param_scan(10.1)
+        self.assertEqual(self.worker.command_quiet_until, 16)
+        self.worker.connection.mav.param_request_read_send.assert_not_called()
+        self.worker.connection.mav.command_long_send.assert_called_once()
+
+    def test_arm_request_retries_until_state_confirmation(self):
+        self.worker.armed = False
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.command_arm(True)
+        self.worker._tick_arm_retry(10.24)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker._tick_arm_retry(10.25)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 2)
+        self.worker.pending_arm_state = None
+        self.worker._tick_arm_retry(10.50)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 2)
+
+    def test_outbound_command_has_valid_heartbeat_lead_in(self):
+        self.worker._send_mav(self.worker.connection, "timesync_send", 0, 123)
+        names = [call[0] for call in self.worker.connection.mav.method_calls]
+        self.assertEqual(names[-2:], ["heartbeat_send", "timesync_send"])
+
+    def test_disarm_sends_neutral_and_pauses_parameter_traffic(self):
+        self.worker.param_scan.append("SERVO1_FUNCTION")
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.command_arm(False)
+            self.worker.config_paused = False
+            self.worker._tick_param_scan(10.1)
+        self.assertEqual(self.worker.disarm_requested_until, 16)
+        self.assertEqual(self.control_values(),
+                         (1, 0, 0, NEUTRAL_Z, 0, 0))
+        self.worker.connection.mav.param_request_read_send.assert_not_called()
+
+    def test_telemetry_config_is_paced_and_includes_low_rate_esc(self):
+        self.worker.armed = False
+        with patch("app.time.monotonic", return_value=10):
+            self.worker._configure_low_bandwidth_streams()
+        self.assertEqual(len(self.worker.stream_config), 10)
+        self.assertEqual(self.worker.stream_config[-1][0], "ESC_TELEMETRY_1_TO_4")
+        self.assertEqual(self.worker.stream_config[-1][2], 1_000_000)
+        self.worker.connection.mav.command_long_send.assert_not_called()
+        self.worker._tick_stream_config(10)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker._tick_stream_config(10.1)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker.command_quiet_until = 16
+        self.worker._tick_stream_config(11)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 1)
+        self.worker._tick_stream_config(16)
+        self.assertEqual(self.worker.connection.mav.command_long_send.call_count, 2)
+
+    def test_link_probe_uses_configured_rate_and_measures_exact_echo(self):
+        self.worker.armed = False
+        self.worker.ping_rate_hz = 5
+        with patch("app.time.monotonic", return_value=10), \
+             patch("app.time.monotonic_ns", return_value=10_000_000_000):
+            self.worker._tick_link_probe(10)
+        self.worker.connection.mav.timesync_send.assert_called_once_with(
+            0, 10_000_000_000)
+        self.assertEqual(self.worker.pending_pings, {10_000_000_000: 10})
+        self.assertEqual(self.worker.next_ping_at, 10.2)
+        message = SimpleNamespace(
+            tc1=1, ts1=10_000_000_000, get_type=lambda: "TIMESYNC",
+            to_dict=lambda: {"tc1": 1, "ts1": 10_000_000_000})
+        with patch("app.time.monotonic", return_value=10.04):
+            self.worker._handle_message(message)
+        quality = self.worker.events.get_nowait()
+        self.assertEqual(quality[0], "link_quality")
+        self.assertEqual(quality[1]["latency_ms"], 40.0)
+        self.assertEqual(quality[1]["loss_percent"], 0.0)
+
+    def test_link_rates_rebuild_requested_telemetry_intervals(self):
+        self.worker.armed = False
+        with patch("app.time.monotonic", return_value=10):
+            self.worker.set_link_rates(10, {
+                "SYS_STATUS": 5, "SERVO_OUTPUT_RAW": 10,
+                "RC_CHANNELS": 0, "ESC_TELEMETRY_1_TO_4": 2,
+            })
+        self.assertEqual(self.worker.ping_rate_hz, 10)
+        configured = {name: interval for name, _, interval in self.worker.stream_config}
+        self.assertEqual(configured["SYS_STATUS"], 200_000)
+        self.assertEqual(configured["SERVO_OUTPUT_RAW"], 100_000)
+        self.assertEqual(configured["RC_CHANNELS"], -1)
+        self.assertEqual(configured["ESC_TELEMETRY_1_TO_4"], 500_000)
+
+    def test_link_probe_counts_timeout_and_pauses_for_commands(self):
+        self.worker.pending_pings[4] = 5
+        self.worker.rx_delivery_results.extend(((10, True), (10, False)))
+        self.worker.next_ping_at = 0
+        self.worker.command_quiet_until = 20
+        with patch("app.time.monotonic", return_value=10):
+            self.worker._tick_link_probe(10)
+        self.worker.connection.mav.timesync_send.assert_not_called()
+        self.assertEqual(list(self.worker.ping_results), [(10, None)])
+        quality = self.worker.events.get_nowait()[1]
+        self.assertEqual(quality["loss_percent"], 100.0)
+        self.assertEqual(quality["grade"], "testing")
+
+    def test_clean_downlink_cannot_hide_failed_round_trips(self):
+        self.worker.ping_results.extend([(10, None)] * 20)
+        self.worker.rx_delivery_results.extend([(10, True)] * 200)
+        with patch("app.time.monotonic", return_value=10):
+            self.worker._publish_link_quality()
+        quality = self.worker.events.get_nowait()[1]
+        self.assertEqual(quality["loss_percent"], 100.0)
+        self.assertEqual(quality["grade"], "poor")
+
 
 class BridgeTests(unittest.TestCase):
     def test_delayed_arm_after_focus_reset_or_expiry_is_not_sent(self):

tests/ui_windows.cjs

@@ -0,0 +1,140 @@
+/* Browser regression check. Run: node tests/ui_windows.cjs [path-to-playwright]
+   Uses a simulated Python bridge; never opens a COM port or sends MAVLink. */
+const assert=require('node:assert/strict');
+const fs=require('node:fs');
+const path=require('node:path');
+const http=require('node:http');
+const {chromium}=require(process.argv[2]||'playwright');
+const root=path.resolve(__dirname,'..'),output=path.join(root,'runtime','ui-check');
+fs.mkdirSync(output,{recursive:true});
+const server=http.createServer((req,res)=>{
+  const url=decodeURIComponent(new URL(req.url,'http://localhost').pathname);
+  let file=path.resolve(root,'.'+url);
+  if(url==='/model.stl'||url==='/model')file=path.join(root,'runtime','vehicle_model.stl');
+  if(!file.startsWith(root+path.sep)||!fs.existsSync(file)||!fs.statSync(file).isFile()){
+    res.writeHead(404);res.end();return;
+  }
+  const types={'.html':'text/html','.js':'text/javascript','.css':'text/css','.stl':'model/stl'};
+  res.setHeader('Content-Type',types[path.extname(file)]||'application/octet-stream');
+  fs.createReadStream(file).pipe(res);
+});
+async function main(){
+  await new Promise(resolve=>server.listen(0,'127.0.0.1',resolve));
+  const browser=await chromium.launch({headless:true});
+  try{
+    const page=await browser.newPage({viewport:{width:1080,height:720}});
+    const errors=[];page.on('pageerror',error=>errors.push(error.message));
+    await page.addInitScript(()=>{
+      const clone=value=>JSON.parse(JSON.stringify(value));
+      const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,motor:i<=3?i:null,direction:i<=3?1:null};
+      const state={connected:false,armed:false,armed_known:false,mode:null,app_state:'disconnected',status:'Ready',servos,link_quality:null};
+      const battery={cells:4,capacity_mah:5500,c_rating:35,full_v_per_cell:4.2,empty_v_per_cell:3.3,warning_percent:20};
+      const link={baud:57600,control_hz:20,ping_hz:1,system_hz:1,servo_hz:2,rc_hz:2,esc_hz:1};
+      const calls={battery:0,link:0,heavy:0,reverse:0,console:0,connect:[]};
+      const sleep=ms=>new Promise(resolve=>setTimeout(resolve,ms));
+      window.testBridge={state,battery,link,calls,failBattery:false,failMotor:false};
+      window.pywebview={api:{
+        initial_state:async()=>({ports:[{device:'COM5',label:'COM5'}],state:clone(state),battery_config:clone(battery),link_config:clone(link)}),
+        refresh_ports:async()=>[{device:'COM5',label:'COM5'}],poll:async()=>clone(state),
+        get_saved_model_info:async()=>null,set_gain:async()=>true,stop_controls:async()=>true,set_axes:async()=>true,
+        save_battery:async data=>{calls.battery++;await sleep(200);if(window.testBridge.failBattery)throw Error('Battery save failed');Object.keys(battery).forEach(k=>battery[k]=+data[k]);return clone(battery)},
+        save_link_settings:async data=>{calls.link++;await sleep(250);Object.keys(link).forEach(k=>link[k]=+data[k]);return clone(link)},
+        connect:async(port,baud,rate)=>{calls.connect.push({port,baud,rate});Object.assign(state,{connected:true,armed_known:true,app_state:'connected_disarmed',mode:'MANUAL',link:'LINK OK',link_quality:{grade:'excellent',probe_samples:20,rx_packets_30s:100,rtt_median_ms:24,rtt_p95_ms:40,probe_loss_percent:0,rx_sequence_loss_percent:0,heartbeat_age_s:.2}});return clone(state)},
+        disconnect:async()=>{Object.assign(state,{connected:false,armed_known:false,app_state:'disconnected'});return true},
+        reverse_motor:async servo=>{calls.reverse++;if(window.testBridge.failMotor)throw Error('Motor write failed');setTimeout(()=>state.servos[servo].direction*=-1,650);return true},
+        set_servo_function:async(servo,motor)=>{if(window.testBridge.failMotor)throw Error('Motor write failed');setTimeout(()=>Object.assign(state.servos[servo],{motor:motor||null,function:motor===0?0:motor<=8?32+motor:73+motor,direction:motor?1:null}),650);return true},
+        start_heavy_quality_test:async()=>{calls.heavy++;await sleep(250);state.heavy_quality={running:true,status:'Stage 1 of 3: 1 Hz',sent:4,replies:4,results:[]};return clone(state.heavy_quality)},
+        cancel_heavy_quality_test:async()=>{state.heavy_quality={running:false,status:'Cancelled',results:[]};return clone(state.heavy_quality)},
+        read_console:async()=>{calls.console++;return {rx:['RX sample '+calls.console],tx:['TX sample '+calls.console]}},
+        minimize_window:async()=>true,toggle_maximize_window:async()=>false,close_window:async()=>true
+      }};
+    });
+    await page.goto('http://127.0.0.1:'+server.address().port+'/web/index.html');
+    await page.waitForFunction(()=>bridgeReady);
+    const openLink=()=>page.locator('[data-open="link-modal"]').click();
+    const close=async id=>{await page.locator('#'+id+' [data-close]').first().click();await page.waitForFunction(id=>!document.getElementById(id).open,id)};
+    await openLink();
+    await page.locator('#baud').selectOption('115200');
+    await page.locator('#link-modal').getByRole('button',{name:'Cancel',exact:true}).click();
+    await page.waitForFunction(()=>!document.getElementById('link-modal').open);
+    await openLink();assert.equal(await page.locator('#baud').inputValue(),'57600');
+    await page.locator('#custom-port-input').fill('COM42');
+    await page.locator('#custom-port-btn').click();
+    assert(await page.locator('#link-modal').evaluate(d=>d.open));
+    assert.equal(await page.locator('#port').inputValue(),'COM42');
+    await page.locator('#baud').selectOption('115200');
+    assert(await page.locator('#link-form [type="submit"]').evaluate(el=>{el.click();return el.disabled}));
+    await page.waitForFunction(()=>!document.getElementById('link-modal').open);
+    await page.locator('#refresh').click();assert.equal(await page.locator('#port').inputValue(),'COM42');
+    await page.locator('#connect').click();
+    await page.waitForFunction(()=>testBridge.calls.connect.length===1);
+    assert.equal(await page.evaluate(()=>testBridge.calls.connect[0].baud),115200);
+    await page.locator('[data-open="battery-modal"]').click();
+    await page.locator('#battery-form [name="cells"]').fill('5');
+    await page.keyboard.press('Escape');await page.waitForFunction(()=>!document.getElementById('battery-modal').open);
+    await page.locator('[data-open="battery-modal"]').click();
+    assert.equal(await page.locator('#battery-form [name="cells"]').inputValue(),'4');
+    await page.evaluate(()=>testBridge.failBattery=true);
+    await page.locator('#battery-form').getByRole('button',{name:'Save battery'}).click();
+    await page.locator('#battery-form .form-feedback').waitFor({state:'visible'});
+    assert(await page.locator('#battery-modal').evaluate(d=>d.open));
+    assert.equal(await page.locator('#battery-form .form-feedback').textContent(),'Battery save failed');
+    await page.evaluate(()=>testBridge.failBattery=false);
+    await page.locator('#battery-form [name="cells"]').fill('5');
+    await page.locator('#battery-form').getByRole('button',{name:'Save battery'}).click();
+    await page.waitForFunction(()=>!document.getElementById('battery-modal').open);
+    await page.locator('[data-open="battery-modal"]').click();
+    assert.equal(await page.locator('#battery-form [name="cells"]').inputValue(),'5');
+    await page.screenshot({path:path.join(output,'battery.png')});await close('battery-modal');
+    await page.locator('[data-open="motors-modal"]').click();
+    assert.equal(await page.locator('#motor-list > .motor-row').count(),3);
+    await page.locator('#motor-list > .motor-row').first().getByRole('button').click();
+    await page.waitForFunction(()=>document.querySelector('#motor-list > .motor-row > span').textContent==='Confirming…');
+    assert(await page.locator('#motor-list > .motor-row').first().getByRole('button').isDisabled());
+    await page.waitForFunction(()=>document.querySelector('#motor-list > .motor-row > span').textContent==='Reversed');
+    await page.evaluate(()=>testBridge.failMotor=true);
+    await page.locator('#motor-list > .motor-row').first().locator('select').selectOption('2');
+    await page.locator('#motor-feedback').waitFor({state:'visible'});
+    assert.equal(await page.locator('#motor-list > .motor-row').first().locator('select').inputValue(),'1');
+    await page.screenshot({path:path.join(output,'motors.png')});await close('motors-modal');
+    await page.locator('#link-quality').click();
+    assert.equal(await page.locator('#quality-detail-rtt').textContent(),'24 ms');
+    await page.locator('#heavy-quality-run').click();
+    assert(await page.locator('#heavy-quality-run').isDisabled());
+    await page.locator('#heavy-quality-cancel').waitFor({state:'visible'});
+    assert.equal(await page.evaluate(()=>testBridge.calls.heavy),1);
+    await page.locator('#heavy-quality-cancel').click();
+    await page.waitForFunction(()=>!testBridge.state.heavy_quality.running);
+    await page.screenshot({path:path.join(output,'quality.png')});await close('link-quality-modal');
+    await page.locator('#console').click();
+    await page.waitForFunction(()=>document.getElementById('console-rx-output').textContent.includes('RX sample'));
+    await page.locator('#console-pause').click();
+    const paused=await page.locator('#console-rx-output').textContent();
+    await page.waitForTimeout(850);assert.equal(await page.locator('#console-rx-output').textContent(),paused);
+    await page.locator('#console-pause').click();
+    await page.waitForFunction(old=>document.getElementById('console-rx-output').textContent!==old,paused);
+    await page.screenshot({path:path.join(output,'console.png')});await close('console-modal');
+    for(const viewport of [{width:900,height:560},{width:480,height:720}]){
+      await page.setViewportSize(viewport);
+      for(const id of ['link-modal','battery-modal','link-quality-modal','motors-modal','console-modal']){
+        await page.evaluate(id=>openModal(id),id);
+        const box=await page.locator('#'+id).boundingBox();
+        assert(box.x>=0&&box.y>=0&&box.width<=viewport.width&&box.height<=viewport.height,id+' must fit viewport');
+        assert.equal(await page.evaluate(()=>canDrive()),false);
+        await close(id);
+      }
+    }
+    await page.setViewportSize({width:1080,height:720});await openLink();
+    await page.screenshot({path:path.join(output,'link.png')});await close('link-modal');
+    assert.deepEqual(errors,[]);
+    console.log('PASS: settings cancel/save/failure, saved baud, custom port rescan, motor confirmation/failure, heavy test, console pause/resume, keyboard gating, and five dialogs at two window sizes.');
+  }catch(error){
+    const page=browser.contexts()[0]?.pages()[0];
+    if(page){
+      await page.screenshot({path:path.join(output,'failure.png')});
+      console.error(await page.evaluate(()=>[...document.querySelectorAll('input')].filter(el=>!el.checkValidity()).map(el=>({name:el.name,value:el.value,error:el.validationMessage}))));
+    }
+    throw error;
+  }finally{await browser.close();await new Promise(resolve=>server.close(resolve))}
+}
+main().catch(error=>{console.error(error);server.close();process.exitCode=1});

web/app.js

@@ -6,7 +6,7 @@ const STATUS_LABELS = {
   link_degraded: 'Signal lost — check tether',
 };
 const $=s=>document.querySelector(s), $$=s=>[...document.querySelectorAll(s)];
-const control={forward:0,turn:0,vertical:0}, pressedKeys=new Set(); let bridgeReady=false, appState='disconnected', batteryConfig={}, servoSignature='', lastAxisSend=0, axisTimer=0, demoActive=false, demoState=null;
+const control={forward:0,turn:0,vertical:0}, pressedKeys=new Set(); let bridgeReady=false, appState='disconnected', batteryConfig={}, linkConfig={baud:57600,control_hz:20,ping_hz:1,system_hz:1,servo_hz:2,rc_hz:2,esc_hz:1}, servoSignature='', lastAxisSend=0, axisTimer=0, demoActive=false, demoState=null;
 const api=(name,...args)=>window.pywebview.api[name](...args);
 const activity=[];
 let lastReportedStatus='';
@@ -21,13 +21,14 @@ function withTimeout(promise,ms=1500){return new Promise((resolve,reject)=>{cons
 let vehicleSnapshot={connected:false,armed:null}, view=ControlState.present(vehicleSnapshot), inputFocused=true,
     bridgeStale=false,lastBridgeAt=performance.now(),axisBusy=false,inputSequence=Date.now(),
     localRequest=null,commandError='',requestSerial=0,demoCommandTimer=0,lastSafetyTick=performance.now();
-const canDrive=()=>view.drive&&performance.now()-lastSafetyTick<750;
+const canDrive=()=>view.drive&&!document.querySelector('dialog[open]')&&performance.now()-lastSafetyTick<750;
 window.canDrive=canDrive;
-function makeDemoState(){const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,label:i<=3?`Motor ${i}`:'Unassigned',motor:i<=3?i:null,direction:i<=3?1:null};return {connected:true,link:'LINK OK',vehicle:'DEMO • DISARMED',armed:false,armed_known:true,mode:'MANUAL',app_state:'connected_disarmed',status:'Demo mode ready — no hardware or spoofer.',battery:{voltage:15.8,per_cell:3.95,percent:72,cells:4,low:false},servos}}
+function makeDemoState(){const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,label:i<=3?`Motor ${i}`:'Unassigned',motor:i<=3?i:null,direction:i<=3?1:null};return {connected:true,link:'LINK OK',vehicle:'DEMO • DISARMED',armed:false,armed_known:true,mode:'MANUAL',app_state:'connected_disarmed',status:'Demo mode ready — no hardware or spoofer.',battery:{voltage:15.8,per_cell:3.95,percent:72,cells:4,low:false},link_quality:null,servos}}
 function updateDemo(patch){Object.assign(demoState,patch);render(demoState)}
 document.addEventListener('click',e=>{const btn=e.target.closest('.num-step');if(!btn)return;const pill=btn.closest('.number-pill');if(!pill)return;const input=pill.querySelector('input');if(!input)return;const step=+input.step||1,min=input.min!==''?+input.min:-Infinity,max=input.max!==''?+input.max:Infinity;let val=+input.value||0;if(btn.classList.contains('down'))val=Math.max(min,+(val-step).toFixed(4));else val=Math.min(max,+(val+step).toFixed(4));input.value=val;input.dispatchEvent(new Event('input',{bubbles:true}));input.dispatchEvent(new Event('change',{bubbles:true}))});
 function toast(message,error=false){const el=$('#toast');el.textContent=message;el.className=`toast show${error?' error':''}`;clearTimeout(toast.t);toast.t=setTimeout(()=>el.className='toast',2600)}
 window.showToast=toast;
+const manualPorts=new Map();
 function populatePorts(ports){
   const p=$('#port');
   if(!p)return;
@@ -50,6 +51,7 @@ function populatePorts(ports){
   };
 
   if(Array.isArray(ports)) ports.forEach(addPort);
+  manualPorts.forEach(addPort);
   addPort({device:'demo', label:'Demo Mode (no hardware)'});
 
   let matched=false;
@@ -94,7 +96,7 @@ function easeHeave(target=0){cancelAnimationFrame(heaveAnim);const sv=control.ve
 window.verticalControl={setPos:value=>{cancelAnimationFrame(heaveAnim);setHeave(value)},easeBack:()=>{if(heavePointer===null)easeHeave()},getState:()=>({value:control.vertical,active:heavePointer!==null})};
 
 function applyKeys(){if(!canDrive()){pressedKeys.clear();return;}const turn=(pressedKeys.has('d')||pressedKeys.has('e')?1:0)-(pressedKeys.has('a')||pressedKeys.has('q')?1:0),forward=(pressedKeys.has('w')?1:0)-(pressedKeys.has('s')?1:0),vertical=(pressedKeys.has('r')?1:0)-(pressedKeys.has('f')?1:0);if(!window.joystick3D?.getState().active)window.joystick3D?.easeTo(turn,-forward);if(heavePointer===null)easeHeave(vertical)}
-addEventListener('keydown',e=>{if(e.key==='F3'){e.preventDefault();if(!e.repeat&&view.action==='disarm')requestControl('disarm');return;}if(/^(INPUT|SELECT|TEXTAREA)$/.test(e.target.tagName))return;if(e.key==='F2'){e.preventDefault();if(!e.repeat)startEngageHold();return;}const k=e.key.toLowerCase();if('wasdqerf'.includes(k)&&k.length===1){if(!canDrive())return;e.preventDefault();if(!pressedKeys.has(k)){pressedKeys.add(k);applyKeys();}}});addEventListener('keyup',e=>{if(e.key==='F2'){e.preventDefault();cancelEngageHold(true);return;}const k=e.key.toLowerCase();if(pressedKeys.delete(k))applyKeys();});
+addEventListener('keydown',e=>{if(e.key==='F3'){e.preventDefault();if(!e.repeat&&view.action==='disarm')requestControl('disarm');return;}if(document.querySelector('dialog[open]')||/^(INPUT|SELECT|TEXTAREA)$/.test(e.target.tagName))return;if(e.key==='F2'){e.preventDefault();if(!e.repeat)startEngageHold();return;}const k=e.key.toLowerCase();if('wasdqerf'.includes(k)&&k.length===1){if(!canDrive())return;e.preventDefault();if(!pressedKeys.has(k)){pressedKeys.add(k);applyKeys();}}});addEventListener('keyup',e=>{if(e.key==='F2'){e.preventDefault();cancelEngageHold(true);return;}const k=e.key.toLowerCase();if(pressedKeys.delete(k))applyKeys();});
 function resetInputs(){
   if(gainPointer!==null)releaseGain({pointerId:gainPointer});
   clearTimeout(axisTimer);axisTimer=0;pressedKeys.clear();cancelEngageHold(false);
@@ -111,28 +113,62 @@ addEventListener('focus',()=>focusChanged(!document.hidden));
 document.addEventListener('visibilitychange',()=>focusChanged(!document.hidden&&document.hasFocus()));
 addEventListener('pagehide',()=>focusChanged(false));
 
+function setFeedback(el,message=''){
+  if(!el)return;
+  el.textContent=message;el.hidden=!message;
+}
 function openModal(id){
   const el=typeof id==='string'?document.getElementById(id):id;
-  if(!el)return;
+  if(!el||el.open)return;
+  resetInputs();
+  el._returnFocus=document.activeElement;
+  if(el.id==='battery-modal')fillBatteryForm();
+  if(el.id==='link-modal'){
+    fillLinkForm();
+    $('#custom-port-status').textContent='';
+    $('#custom-port-input').value='';
+  }
+  el.querySelectorAll('.form-feedback').forEach(feedback=>setFeedback(feedback));
   el.classList.remove('closing');
-  if(!el.open)el.showModal();
+  el.showModal();
 }
 function closeModal(dialog){
-  if(!dialog||!dialog.open||dialog.classList.contains('closing'))return;
+  if(!dialog||!dialog.open||dialog.classList.contains('closing')||dialog.querySelector('[data-busy="true"]'))return;
   dialog.classList.add('closing');
   let done=false;
   const finish=()=>{
     if(done)return;
     done=true;
-    dialog.removeEventListener('animationend',finish);
+    dialog.removeEventListener('animationend',onEnd);
     dialog.classList.remove('closing');
     dialog.close();
+    if(dialog._returnFocus?.isConnected)dialog._returnFocus.focus({preventScroll:true});
   };
-  dialog.addEventListener('animationend',finish,{once:true});
+  const onEnd=e=>{if(e.target===dialog)finish()};
-  setTimeout(finish,300);
+  dialog.addEventListener('animationend',onEnd);
+  setTimeout(finish,180);
 }
 $$('[data-open]').forEach(b=>b.onclick=()=>openModal(b.dataset.open));
 $$('[data-close]').forEach(b=>b.onclick=()=>closeModal(b.closest('dialog')));
+$('#link-quality').onclick=()=>openModal('link-quality-modal');
+let heavyActionBusy=false;
+async function requestHeavyTest(action){
+  if(heavyActionBusy)return;
+  heavyActionBusy=true;
+  setFeedback($('#heavy-quality-error'));
+  renderHeavyQuality(vehicleSnapshot.heavy_quality,vehicleSnapshot.connected,vehicleSnapshot.armed);
+  try{
+    const test=await api(action);
+    vehicleSnapshot.heavy_quality=test;
+    renderHeavyQuality(test,vehicleSnapshot.connected,vehicleSnapshot.armed);
+  }catch(e){setFeedback($('#heavy-quality-error'),e.message||'Link test unavailable. Try again.')}
+  finally{
+    heavyActionBusy=false;
+    renderHeavyQuality(vehicleSnapshot.heavy_quality,vehicleSnapshot.connected,vehicleSnapshot.armed);
+  }
+}
+$('#heavy-quality-run').onclick=()=>requestHeavyTest('start_heavy_quality_test');
+$('#heavy-quality-cancel').onclick=()=>requestHeavyTest('cancel_heavy_quality_test');
 $$('dialog').forEach(d=>{
   d.addEventListener('cancel',e=>{e.preventDefault();closeModal(d)});
   d.addEventListener('click',e=>{
@@ -255,7 +291,7 @@ $('#connect').onclick=async()=>{
     recordActivity(`Connecting to ${port}…`);
     toast(`Connecting to ${port}…`);
     try{
-      const confirmedState=await api('connect',port,+$('#baud').value,+$('#rate').value);
+      const confirmedState=await api('connect',port,+linkConfig.baud||57600,+linkConfig.control_hz||20);
       if(confirmedState)render(confirmedState);
       toast(confirmedState?.armed_known?'MAVLink connected':'Waiting for vehicle telemetry',!confirmedState?.armed_known);
     }catch(e){
@@ -270,7 +306,9 @@ const customPortBtn=$('#custom-port-btn'), customPortInput=$('#custom-port-input
 if(customPortBtn&&customPortInput){
   const applyCustomPort=()=>{
     const val=customPortInput.value.trim();
-    if(!val)return;
+    if(!val){$('#custom-port-status').textContent='Enter a port first.';customPortInput.focus();return;}
+    if(vehicleSnapshot.connected)return;
+    manualPorts.set(val,{device:val,label:`Custom (${val})`});
     const p=$('#port');
     let exists=false;
     for(const opt of p.options){
@@ -280,8 +318,7 @@ if(customPortBtn&&customPortInput){
       p.add(new Option(`Custom (${val})`, val), 0);
       p.value=val;
     }
-    closeModal($('#link-modal'));
+    $('#custom-port-status').textContent=`Selected ${val}. Apply settings, then connect.`;
-    toast(`Selected port: ${val}`);
   };
   customPortBtn.onclick=applyCustomPort;
   customPortInput.onkeydown=e=>{if(e.key==='Enter'){e.preventDefault();applyCustomPort();}};
@@ -380,6 +417,34 @@ if(engageButton){
 }
 
 $('#logs').onclick=()=>api('open_logs');
+const consoleDialog=$('#console-modal'),consoleRx=$('#console-rx-output'),consoleTx=$('#console-tx-output');
+let consoleRefreshBusy=false,consolePaused=false;
+$('#console-pause').onclick=()=>{
+  consolePaused=!consolePaused;
+  $('#console-pause').textContent=consolePaused?'Resume':'Pause';
+  $('#console-pause').setAttribute('aria-pressed',String(consolePaused));
+  $('#console-state').textContent=consolePaused?'Paused · session logging continues':'Live · follows new messages';
+  if(!consolePaused)refreshConsole();
+};
+async function refreshConsole(){
+  if(!consoleDialog?.open||!bridgeReady||consoleRefreshBusy||consolePaused)return;
+  consoleRefreshBusy=true;
+  try{
+    const rxAtBottom=consoleRx.scrollHeight-consoleRx.scrollTop-consoleRx.clientHeight<36;
+    const txAtBottom=consoleTx.scrollHeight-consoleTx.scrollTop-consoleTx.clientHeight<36;
+    const sides=await api('read_console',150);
+    if(consolePaused||!consoleDialog.open)return;
+    consoleRx.textContent=sides.rx?.length?sides.rx.join('\n'):'Waiting for vehicle data…';
+    consoleTx.textContent=sides.tx?.length?sides.tx.join('\n'):'Waiting for transmitted data…';
+    if(rxAtBottom)consoleRx.scrollTop=consoleRx.scrollHeight;
+    if(txAtBottom)consoleTx.scrollTop=consoleTx.scrollHeight;
+  }catch(error){
+    $('#console-state').textContent=`Console unavailable: ${error.message}`;
+  }
+  finally{consoleRefreshBusy=false}
+}
+$('#console').onclick=()=>{openModal(consoleDialog);refreshConsole()};
+setInterval(refreshConsole,750);
 function setGain(value){const gain=$('#gain');gain.value=Math.max(+gain.min,Math.min(+gain.max,value));$('#gain-value').textContent=`${gain.value}%`;if(bridgeReady)api('set_gain',+gain.value)}
 $('#gain').oninput=e=>setGain(+e.target.value);$('#gain-down').onclick=()=>setGain(+$('#gain').value-5);$('#gain-up').onclick=()=>setGain(+$('#gain').value+5);
 // Explicit pointer ownership makes the full range rail a reliable touch target
@@ -391,9 +456,108 @@ gainSlider.addEventListener('pointerdown',e=>{if(gainPointer!==null||e.button>0)
 gainSlider.addEventListener('pointermove',e=>{if(e.pointerId===gainPointer)gainFromPointer(e)});
 ['pointerup','pointercancel','lostpointercapture'].forEach(type=>gainSlider.addEventListener(type,releaseGain));
 gainSlider.addEventListener('keydown',e=>{const delta={ArrowRight:1,ArrowUp:1,ArrowLeft:-1,ArrowDown:-1}[e.key];if(delta){e.preventDefault();setGain(+gainSlider.value+delta)}else if(e.key==='Home'||e.key==='End'){e.preventDefault();setGain(+(e.key==='Home'?gainSlider.min:gainSlider.max))}});
-$('#battery-form').onsubmit=async e=>{e.preventDefault();const data=Object.fromEntries(new FormData(e.target));try{batteryConfig=await api('save_battery',data);closeModal($('#battery-modal'));toast('Battery settings saved')}catch(err){toast(err.message,true)}};
+async function saveSettings(form,method,commit,message){
+  if(form.dataset.busy==='true'||!form.reportValidity())return;
+  const data=Object.fromEntries(new FormData(form));
+  const button=form.querySelector('[type="submit"]'),label=button.textContent;
+  const disabled=new Map([...form.querySelectorAll('input,select,button')].map(el=>[el,el.disabled]));
+  form.dataset.busy='true';disabled.forEach((_,el)=>el.disabled=true);button.textContent='Saving…';
+  setFeedback(form.querySelector('.form-feedback'));
+  let saved=false;
+  try{commit(await api(method,data));saved=true;toast(message)}
+  catch(error){setFeedback(form.querySelector('.form-feedback'),error.message||'Could not save settings. Try again.')}
+  finally{
+    delete form.dataset.busy;disabled.forEach((value,el)=>el.disabled=value);button.textContent=label;
+    if(saved)closeModal(form.closest('dialog'));
+  }
+}
+$('#battery-form').onsubmit=e=>{e.preventDefault();saveSettings(e.target,'save_battery',value=>batteryConfig=value,'Battery settings saved')};
 function fillBatteryForm(){for(const [k,v] of Object.entries(batteryConfig)){const el=$(`#battery-form [name=${k}]`);if(el)el.value=v}}
-function renderMotors(servos){const signature=JSON.stringify(servos);if(signature===servoSignature)return;servoSignature=signature;const list=$('#motor-list');list.innerHTML='';for(let i=1;i<=16;i++){const s=servos[String(i)]||{},row=document.createElement('div');row.className='motor-row';const opts=['<option value="0">Unassigned</option>',...Array.from({length:12},(_,n)=>`<option value="${n+1}" ${s.motor===n+1?'selected':''}>Motor ${n+1}</option>`)].join('');row.innerHTML=`<strong>SERVO${i}</strong><select aria-label="SERVO${i} function">${opts}</select><span>${s.direction==null?'—':s.direction===-1?'Reversed':'Normal'}</span><button class="button subtle">Reverse</button>`;row.querySelector('select').onchange=e=>{if(demoActive){const motor=+e.target.value;demoState.servos[String(i)]={function:motor?32+motor:0,label:motor?`Motor ${motor}`:'Unassigned',motor:motor||null,direction:motor?1:null};servoSignature='';renderMotors(demoState.servos);toast(`Demo SERVO${i} updated`)}else api('set_servo_function',i,+e.target.value).catch(x=>toast(x.message,true))};row.querySelector('button').onclick=()=>{if(demoActive){if(s.motor){s.direction=s.direction===-1?1:-1;servoSignature='';renderMotors(demoState.servos);toast(`Demo Motor ${s.motor} reversed`)}else toast(`SERVO${i} is unassigned`,true)}else api('reverse_motor',i).catch(x=>toast(x.message,true))};list.append(row)}}
+$('#link-form').onsubmit=e=>{e.preventDefault();saveSettings(e.target,'save_link_settings',value=>linkConfig=value,'Link settings applied')};
+function fillLinkForm(){for(const [k,v] of Object.entries(linkConfig)){const el=$(`#link-form [name=${k}]`);if(el)el.value=v}}
+const motorEdits=new Map();
+async function requestMotorEdit(servo,kind,value){
+  if(motorEdits.has(servo))return;
+  const s=vehicleSnapshot.servos?.[String(servo)]||{};
+  const expected=kind==='function'?(value===0?0:value<=8?32+value:73+value):-s.direction;
+  setFeedback($('#motor-feedback'));
+  if(demoActive){
+    if(kind==='function')Object.assign(s,{function:expected,motor:value||null,direction:value?1:null});
+    else s.direction=expected;
+    servoSignature='';renderMotors(demoState.servos);toast('Demo motor updated');return;
+  }
+  motorEdits.set(servo,{kind,expected,started:performance.now()});
+  servoSignature='';renderMotors(vehicleSnapshot.servos||{});
+  try{
+    await api(kind==='function'?'set_servo_function':'reverse_motor',servo,...(kind==='function'?[value]:[]));
+  }catch(error){
+    motorEdits.delete(servo);
+    setFeedback($('#motor-feedback'),error.message||'Motor change failed. Try again.');
+    servoSignature='';renderMotors(vehicleSnapshot.servos||{});
+  }
+}
+function renderMotors(servos){
+  for(const [servo,edit] of motorEdits){
+    const s=servos[String(servo)]||{};
+    if((edit.kind==='function'?s.function:s.direction)===edit.expected){
+      motorEdits.delete(servo);toast(`SERVO${servo} change confirmed`);
+    }else if(!vehicleSnapshot.connected||performance.now()-edit.started>8000){
+      motorEdits.delete(servo);
+      setFeedback($('#motor-feedback'),`SERVO${servo}: confirmation not received. Check the reported assignment before retrying.`);
+    }
+  }
+  const editable=!!vehicleSnapshot.connected&&!vehicleSnapshot.armed&&(demoActive||view.known);
+  const assigned=Object.values(servos).filter(s=>s.motor).length;
+  $('#motor-status').textContent=vehicleSnapshot.armed?'Disarm to change assignments or direction.':!vehicleSnapshot.connected?'Connect to read motor outputs.':assigned?`${assigned} motor${assigned===1?'':'s'} assigned · changes wait for vehicle confirmation.`:'Reading motor assignments…';
+  const signature=JSON.stringify([servos,editable,[...motorEdits]]);
+  if(signature===servoSignature)return;
+  servoSignature=signature;
+  const list=$('#motor-list'),expanded=list.querySelector('details')?.open;
+  list.replaceChildren();
+  const other=document.createElement('details');other.className='motor-other';other.open=!!expanded;
+  const summary=document.createElement('summary');summary.textContent=`Other outputs (${16-assigned})`;other.append(summary);
+  for(let i=1;i<=16;i++){
+    const s=servos[String(i)]||{},pending=motorEdits.get(i),row=document.createElement('div');row.className='motor-row';
+    row.innerHTML=`<strong>SERVO${i}</strong><select aria-label="SERVO${i} assignment"></select><span></span><button type="button" class="button subtle">Reverse</button>`;
+    const select=row.querySelector('select');
+    select.add(new Option(s.function==null?'Reading…':'Unassigned','0'));
+    for(let motor=1;motor<=12;motor++)select.add(new Option(`Motor ${motor}`,String(motor)));
+    select.value=String(s.motor||0);
+    select.disabled=!editable||!!pending||s.function==null;
+    select.onchange=e=>requestMotorEdit(i,'function',+e.target.value);
+    row.querySelector('span').textContent=pending?'Confirming…':s.direction==null?'—':s.direction===-1?'Reversed':'Normal';
+    const reverse=row.querySelector('button');reverse.disabled=!editable||!!pending||!s.motor||s.direction==null;
+    reverse.setAttribute('aria-label',`Reverse SERVO${i} motor direction`);
+    reverse.onclick=()=>requestMotorEdit(i,'direction');
+    (s.motor?list:other).append(row);
+  }
+  if(!assigned){const empty=document.createElement('p');empty.className='note';empty.textContent='Assigned motors will appear here.';list.append(empty)}
+  if(assigned<16)list.append(other);
+}
+function renderHeavyQuality(test,connected,armed){
+  const status=$('#heavy-quality-status'),results=$('#heavy-quality-results'),run=$('#heavy-quality-run'),stop=$('#heavy-quality-cancel');
+  if(!status||!results||!run||!stop)return;
+  const quality=demoActive?null:vehicleSnapshot.link_quality;
+  $('#quality-detail-rtt').textContent=quality?.rtt_median_ms==null?'—':`${Math.round(quality.rtt_median_ms)} ms`;
+  $('#quality-detail-loss').textContent=quality?.probe_loss_percent==null?'—':`${quality.probe_loss_percent.toFixed(1)}%`;
+  $('#quality-detail-downlink').textContent=quality?.rx_sequence_loss_percent==null?'—':`${quality.rx_sequence_loss_percent.toFixed(1)}%`;
+  const running=!!test?.running;
+  status.textContent=running?`${test.status} · ${test.replies||0}/${test.sent||0} replies`:(test?.status==='Complete'?'Test complete. Results below.':test?.status==='Cancelled'?'Test stopped. Partial results below.':demoActive?'Demo has no hardware link to measure.':!connected?'Connect to run a test.':armed?'Disarm to run a test.':'Ready to test.');
+  run.disabled=heavyActionBusy||running||!connected||armed||demoActive;
+  run.textContent=!connected?'Connect to run test':armed?'Disarm to run test':demoActive?'Unavailable in demo':test?.status==='Complete'?'Run again':'Run heavy test';
+  stop.hidden=!running;
+  stop.disabled=heavyActionBusy;
+  results.replaceChildren();
+  for(const row of test?.results||[]){
+    const line=document.createElement('div');line.className='heavy-result-row';
+    const rate=document.createElement('strong');rate.textContent=`${row.rate_hz} Hz`;
+    const stats=document.createElement('span');
+    const loss=row.loss_percent==null?'—':`${row.loss_percent.toFixed(1)}% loss`;
+    const rtt=row.median_rtt_ms==null?'—':`${row.median_rtt_ms.toFixed(0)} ms median / ${row.p95_rtt_ms.toFixed(0)} ms p95`;
+    stats.textContent=`${row.replies}/${row.sent} replies · ${loss} · ${rtt}`;
+    line.append(rate,stats);results.append(line);
+  }
+}
 function render(s,confirmed=false){
   vehicleSnapshot=s;
   if(confirmed&&localRequest?.sent && (s.pending_command===localRequest.name || s.command_error ||
@@ -402,10 +566,13 @@ function render(s,confirmed=false){
   view=ControlState.present(s,{stale:bridgeStale,focused:inputFocused,pending:localRequest?.name,error:commandError});
   if((previous.drive&&!view.drive)||(previous.action==='arm'&&view.action!=='arm'))resetInputs();
   appState=bridgeStale&&s.connected?'link_degraded':s.app_state||'disconnected';
+  renderHeavyQuality(s.heavy_quality,s.connected,s.armed);
   document.body.dataset.appState=appState;
   document.body.dataset.controlsEnabled=String(view.drive);
   document.body.dataset.telemetryStale=String(!view.known||!!s.battery_stale);
   $('#port').disabled=!!s.connected;
+  $('#custom-port-input').disabled=!!s.connected||$('#link-form').dataset.busy==='true';
+  $('#custom-port-btn').disabled=!!s.connected||$('#link-form').dataset.busy==='true';
   const isOnline=(appState==='connected_disarmed'||appState==='armed');
   const connectBtn=$('#connect');
   const connectLabel=connectBtn?connectBtn.querySelector('.btn-label'):null;
@@ -456,6 +623,37 @@ function render(s,confirmed=false){
     $('#battery-percent').textContent='waiting';
     $('#battery-fill').style.width='0';
   }
+  const quality=s.link_quality,qualityCard=$('#link-quality');
+  if(qualityCard){
+    if(demoActive){
+      qualityCard.dataset.grade='offline';
+      $('#link-quality-grade').textContent='Demo';
+      $('#link-quality-roundtrip').textContent='no hardware link test';
+      $('#link-quality-downlink').textContent='';
+      renderMotors(s.servos||{});
+      return;
+    }
+    const grade=quality?.grade||(s.connected?'testing':'offline');
+    qualityCard.dataset.grade=grade;
+    $('#link-quality-grade').textContent=grade.charAt(0).toUpperCase()+grade.slice(1);
+    if(quality&&quality.probe_samples){
+      const percent=value=>value==null?'—':`${value.toFixed(1)}%`;
+      const median=quality.rtt_median_ms==null?'—':`${Math.round(quality.rtt_median_ms)} ms`;
+      const p95=quality.rtt_p95_ms==null?'—':`${Math.round(quality.rtt_p95_ms)} ms`;
+      $('#link-quality-roundtrip').textContent=`round trip ${median} / ${p95} p95 • loss ${percent(quality.probe_loss_percent)}`;
+      const downLoss=percent(quality.rx_sequence_loss_percent);
+      const badFrames=quality.rx_corrupt_frames_20s??0;
+      const badBytes=quality.rx_corrupt_bytes_20s??0;
+      const age=quality.heartbeat_age_s==null?'—':`${quality.heartbeat_age_s.toFixed(1)} s`;
+      $('#link-quality-downlink').textContent=`FC → PC loss ${downLoss} • ${badFrames} bad frames (${badBytes} B) • heartbeat ${age}`;
+      if(quality.probe_samples<10||quality.rx_packets_30s<10){
+        $('#link-quality-grade').textContent=`Testing ${Math.min(quality.probe_samples,quality.rx_packets_30s)}/10`;
+      }
+    }else{
+      $('#link-quality-roundtrip').textContent=s.connected?'testing round trip…':'waiting for connection';
+      $('#link-quality-downlink').textContent='';
+    }
+  }
   renderMotors(s.servos||{});
 }
 
@@ -564,8 +762,10 @@ async function boot(){
     populatePorts(await withTimeout(api('refresh_ports'),4000));
     const init=await withTimeout(api('initial_state'),4000);
     batteryConfig=init.battery_config||{};
+    linkConfig=init.link_config||{};
     populatePorts(init.ports);
     fillBatteryForm();
+    fillLinkForm();
     bridgeReady=true;booted=true;lastBridgeAt=performance.now();
     if(!demoActive)render(init.state);
     poll();

web/index.html

@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width,initial-scale=1">
   <title>Sub Control</title>
-  <link rel="stylesheet" href="styles.css?v=20260827-model-layout-v14">
+  <link rel="stylesheet" href="styles.css?v=20260930-dialogs-v1">
 </head>
 <body>
   <main class="app-shell">
@@ -50,13 +50,19 @@
         <b><em id="battery-fill"></em></b>
       </button>
 
+      <button id="link-quality" type="button" class="link-quality" data-grade="offline" title="Open link-quality details" aria-haspopup="dialog" aria-controls="link-quality-modal">
+        <span class="link-quality-dot" aria-hidden="true"></span>
+        <span><small>Data link</small><strong id="link-quality-grade">Offline</strong></span>
+        <i><span id="link-quality-roundtrip">waiting for connection</span><span id="link-quality-downlink"></span></i>
+      </button>
+
       <div class="deck-status-bar">
         <ol class="activity-history" aria-label="Last three events" aria-live="polite">
           <li id="activity-oldest" hidden></li>
           <li id="activity-previous" hidden></li>
           <li id="status-text">Not connected</li>
         </ol>
-        <header class="activity-heading"><span>Recent activity</span><a id="logs" class="logs-link" title="Open session logs" aria-label="Open session logs">Logs</a></header>
+        <header class="activity-heading"><span>Recent activity</span><span class="activity-actions"><button type="button" id="console" class="logs-link" title="Read live console" aria-label="Read live console">Console</button><button type="button" id="logs" class="logs-link" title="Open session logs" aria-label="Open session logs">Logs</button></span></header>
       </div>
       </section>
 
@@ -146,14 +152,64 @@
   <div id="toast" class="toast"></div>
 
   <!-- Modals -->
-  <dialog id="link-modal" class="modal"><button class="modal-close" data-close>×</button><small>connection</small><h2>Link Settings</h2><div class="form-grid two"><label><span>Baud rate</span><select id="baud"><option>9600</option><option>19200</option><option>38400</option><option selected>57600</option><option>115200</option></select></label><label><span>Control rate</span><select id="rate"><option>10</option><option selected>20</option></select></label></div><div style="margin-top:14px;"><label style="display:flex;flex-direction:column;gap:6px;"><span style="font-size:11px;font-weight:500;color:var(--muted)">Custom Port / Endpoint</span><div style="display:flex;gap:8px;"><input id="custom-port-input" placeholder="e.g. COM3 or tcp:127.0.0.1:5760" style="flex:1;height:32px;padding:0 12px;font-size:11px;"><button type="button" id="custom-port-btn" class="button subtle" style="white-space:nowrap;">Use Port</button></div></label></div><p class="note" style="margin-top:14px;">20 Hz is recommended for smooth intermediate commands on this link.</p></dialog>
+  <dialog id="link-modal" class="modal" aria-labelledby="link-title">
-  <dialog id="battery-modal" class="modal"><button class="modal-close" data-close>×</button><small>Power</small><h2>Battery Settings</h2><form id="battery-form" class="form-grid three"><label><span>Cells (S)</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="cells" type="number" min="1" step="1"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Capacity (mAh)</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="capacity_mah" type="number" min="1" step="50"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>C rating</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="c_rating" type="number" min="1" step=".1"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Full V / cell</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="full_v_per_cell" type="number" step=".01"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Empty V / cell</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="empty_v_per_cell" type="number" step=".01"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><label><span>Warning %</span><div class="number-pill"><button type="button" class="num-step down" tabindex="-1">‹</button><input name="warning_percent" type="number" min="0" max="100" step="1"><button type="button" class="num-step up" tabindex="-1">›</button></div></label><div class="modal-actions wide"><button type="button" class="button subtle" data-close>Cancel</button><button class="button connect-button">Save Settings</button></div></form></dialog>
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Connection</small><h2 id="link-title">Link settings</h2>
-  <dialog id="motors-modal" class="modal motor-modal"><button class="modal-close" data-close>×</button><small>configuration</small><h2>Motor Outputs</h2><p class="note">Function and direction are read one parameter at a time to protect the low-bandwidth link.</p><div class="motor-head"><span>Output</span><span>Function</span><span>Direction</span><span></span></div><div id="motor-list" class="motor-list"></div></dialog>
+    <form id="link-form">
+      <section class="settings-section"><h3>Serial connection</h3>
+        <div class="form-grid two"><label><span>Baud rate</span><select id="baud" name="baud"><option value="9600">9600</option><option value="19200">19200</option><option value="38400">38400</option><option value="57600" selected>57600</option><option value="115200">115200</option></select></label><label><span>Control rate · Hz</span><select id="rate" name="control_hz"><option value="10">10</option><option value="20" selected>20</option></select></label></div>
+        <p class="note">Baud changes apply on the next connection.</p>
+        <label class="custom-port-label"><span>Custom port or endpoint</span><div class="custom-port-row"><input id="custom-port-input" placeholder="COM3 or tcp:127.0.0.1:5760" autocomplete="off"><button type="button" id="custom-port-btn" class="button subtle">Use port</button></div></label>
+        <p id="custom-port-status" class="note" role="status"></p>
+      </section>
+      <section class="settings-section"><h3>Live updates</h3>
+        <div class="form-grid two">
+          <label><span>Quality check · Hz</span><select name="ping_hz"><option value="1" selected>1</option><option value="2">2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>Battery / system · Hz</span><select name="system_hz"><option value="0">Off</option><option value="1" selected>1</option><option value="2">2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>Motor outputs · Hz</span><select name="servo_hz"><option value="0">Off</option><option value="1">1</option><option value="2" selected>2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>RC channels · Hz</span><select name="rc_hz"><option value="0">Off</option><option value="1">1</option><option value="2" selected>2</option><option value="5">5</option><option value="10">10</option></select></label>
+          <label><span>ESC telemetry · Hz</span><select name="esc_hz"><option value="0">Off</option><option value="1" selected>1</option><option value="2">2</option><option value="5">5</option><option value="10">10</option></select></label>
+        </div>
+        <p class="note">Lower rates leave more bandwidth for controls. Vehicle telemetry rates reset after a reboot.</p>
+      </section>
+      <p class="form-feedback" role="alert" hidden></p>
+      <div class="modal-actions"><button type="button" class="button subtle" data-close>Cancel</button><button type="submit" class="button modal-primary">Apply settings</button></div>
+    </form>
+  </dialog>
+  <dialog id="link-quality-modal" class="modal quality-modal" aria-labelledby="quality-title">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Connection</small><h2 id="quality-title">Link quality</h2>
+    <p class="note">The live check watches round-trip replies, incoming packet loss, and heartbeat freshness.</p>
+    <div class="quality-summary"><div><span>Round trip</span><strong id="quality-detail-rtt">—</strong></div><div><span>Probe loss</span><strong id="quality-detail-loss">—</strong></div><div><span>FC → PC loss</span><strong id="quality-detail-downlink">—</strong></div></div>
+    <section class="heavy-test-panel"><h3>Extended test</h3><p class="note">Checks 1, 5, then 10 Hz for about 35 seconds. Run while disarmed; the live echo resumes afterward.</p>
+      <div id="heavy-quality-status" class="heavy-quality-status" role="status">Connect to run an extended test.</div>
+      <div id="heavy-quality-results" class="heavy-quality-results"></div>
+      <p id="heavy-quality-error" class="form-feedback" role="alert" hidden></p>
+      <div class="modal-actions"><button id="heavy-quality-run" type="button" class="button modal-primary">Run extended test</button><button id="heavy-quality-cancel" type="button" class="button subtle" hidden>Stop test</button></div>
+    </section>
+  </dialog>
+  <dialog id="battery-modal" class="modal" aria-labelledby="battery-title-modal">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Power</small><h2 id="battery-title-modal">Battery settings</h2><p class="note">Charge is estimated from voltage. Capacity and C rating describe your battery.</p>
+    <form id="battery-form">
+      <div class="form-grid two"><label><span>Cells · S</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Cells · S">‹</button><input name="cells" type="number" min="1" step="1" max="16" required><button type="button" class="num-step up" aria-label="Increase Cells · S">›</button></div></label><label><span>Capacity · mAh</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Capacity · mAh">‹</button><input name="capacity_mah" type="number" min="50" step="50" required><button type="button" class="num-step up" aria-label="Increase Capacity · mAh">›</button></div></label><label><span>C rating</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease C rating">‹</button><input name="c_rating" type="number" min="1" step="0.1" required><button type="button" class="num-step up" aria-label="Increase C rating">›</button></div></label><label><span>Low charge warning · %</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Low charge warning · %">‹</button><input name="warning_percent" type="number" min="0" step="1" max="100" required><button type="button" class="num-step up" aria-label="Increase Low charge warning · %">›</button></div></label></div>
+      <section class="settings-section"><h3>Voltage per cell</h3><div class="form-grid two"><label><span>Full · V</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Full · V">‹</button><input name="full_v_per_cell" type="number" min="0.01" step="0.01" required><button type="button" class="num-step up" aria-label="Increase Full · V">›</button></div></label><label><span>Empty · V</span><div class="number-pill"><button type="button" class="num-step down" aria-label="Decrease Empty · V">‹</button><input name="empty_v_per_cell" type="number" min="0.01" step="0.01" required><button type="button" class="num-step up" aria-label="Increase Empty · V">›</button></div></label></div></section>
+      <p class="form-feedback" role="alert" hidden></p>
+      <div class="modal-actions"><button type="button" class="button subtle" data-close>Cancel</button><button type="submit" class="button modal-primary">Save battery</button></div>
+    </form>
+  </dialog>
+  <dialog id="motors-modal" class="modal motor-modal" aria-labelledby="motors-title">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Configuration</small><h2 id="motors-title">Motor outputs</h2><p id="motor-status" class="note" role="status">Waiting for motor assignments.</p>
+    <p id="motor-feedback" class="form-feedback" role="alert" hidden></p>
+    <div class="motor-head"><span>Output</span><span>Assignment</span><span>Direction</span><span></span></div><div id="motor-list" class="motor-list"></div>
+  </dialog>
+  <dialog id="console-modal" class="modal console-modal" aria-labelledby="console-title">
+    <button class="modal-close" type="button" data-close aria-label="Close window">×</button><small>Local session</small><h2 id="console-title">Live console</h2>
+    <div class="console-toolbar"><p id="console-state" class="note" role="status">Live · follows new messages</p><button id="console-pause" type="button" class="button subtle" aria-pressed="false">Pause</button></div>
+    <div class="console-split"><section><header><i class="rx-dot"></i><span>RX</span><small>Vehicle → PC</small></header><pre id="console-rx-output" tabindex="0" aria-label="Received messages">Waiting for vehicle data…</pre></section><section><header><i class="tx-dot"></i><span>TX</span><small>PC → Vehicle</small></header><pre id="console-tx-output" tabindex="0" aria-label="Sent messages">Waiting for transmitted data…</pre></section></div>
+  </dialog>
 
   <script src="model-viewer.js?v=20260826-controls-v2"></script>
   <script src="joystick-3d.js?v=20260827-keyboard-v7"></script>
   <script src="control-state.js?v=20260827-state-v1"></script>
-  <script src="app.js?v=20260827-keyboard-v7"></script>
+  <script src="app.js?v=20260930-dialogs-v1"></script>
   <script src="cursor-light.js?v=20260827-directional-v10"></script>
 </body>
 </html>

web/styles.css

@@ -539,6 +539,7 @@ body[data-app-state="link_degraded"] .status-line .status-dot {
   margin-left: auto;
 }
 .logs-link:hover { color: #f1f4f2; }
+.activity-actions { display:flex; align-items:center; gap:12px; }
 
 /* ══════════════════════════════════════════════════════════════════
    PRIMARY CONTROL ZONE (Workspace)
@@ -554,6 +555,59 @@ body[data-app-state="link_degraded"] .status-line .status-dot {
   min-width: 0;
   position: relative;
 }
+
+/* ── Active MAVLink link test ── */
+.link-quality {
+  display: grid;
+  grid-template-columns: 8px minmax(0, 1fr);
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+  min-height: 48px;
+  padding: 3px 0;
+  color: #eef2f0;
+  width: 100%;
+  border: 0;
+  text-align: left;
+  font: inherit;
+  background: transparent;
+  cursor: pointer;
+  border-radius: 9px;
+  transition: background-color .18s ease;
+}
+.link-quality:hover,.link-quality:focus-visible { background:rgba(255,255,255,.055); outline:none; }
+.link-quality-dot {
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: #667074;
+}
+.link-quality span:not(.link-quality-dot) { display:flex; flex-direction:column; gap:1px; min-width:0; }
+.link-quality small { color:#8d979a; font-size:10px; font-weight:400; }
+.link-quality strong { font-size:14px; font-weight:500; line-height:1.15; }
+.link-quality i {
+  grid-column: 2;
+  min-width: 0;
+  color: #aab2b4;
+  font-size: 11px;
+  line-height: 1.3;
+  font-style: normal;
+  white-space: normal;
+  overflow-wrap: anywhere;
+}
+.link-quality i span { display:block; }
+.link-quality[data-grade="excellent"] .link-quality-dot { background:#bce96c; box-shadow:0 0 8px rgba(188,233,108,.35); }
+.link-quality[data-grade="good"] .link-quality-dot { background:#85c7e8; }
+.link-quality[data-grade="fair"] .link-quality-dot { background:#e7bf69; }
+.link-quality[data-grade="poor"] .link-quality-dot { background:#f07f78; box-shadow:0 0 8px rgba(240,127,120,.3); }
+.link-quality[data-grade="testing"] .link-quality-dot { background:#aab3b6; }
+.quality-modal { width:min(520px,calc(100vw - 32px)); }
+.heavy-test-panel { margin-top:18px; padding-top:14px; border-top:1px solid rgba(128,145,145,.2); }
+.heavy-quality-status { font-size:14px; font-weight:500; }
+.heavy-quality-results { display:grid; gap:6px; margin-top:12px; }
+.heavy-result-row { display:flex; justify-content:space-between; gap:12px; align-items:baseline; padding:7px 10px; border-radius:10px; background:rgba(120,140,140,.08); font-size:12px; }
+.heavy-result-row strong { flex:none; }
+.heavy-result-row span { text-align:right; color:var(--muted); }
 .primary-control-zone {
   display: grid;
   grid-template-rows: auto minmax(0, 1fr);
@@ -1025,6 +1079,37 @@ body[data-app-state="link_degraded"] button[data-open="motors-modal"] {
   cursor: not-allowed;
 }
 
+.console-modal {
+  width: min(1040px, calc(100vw - 64px));
+  max-width: 1040px;
+}
+.console-split { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin-top:14px; min-width:0; }
+.console-split section { min-width:0; }
+.console-split header { display:flex; align-items:center; gap:7px; margin:0 2px 7px; }
+.console-split header i { width:7px; height:7px; border-radius:50%; flex:0 0 auto; }
+.console-split header .rx-dot { background:#79c8eb; }
+.console-split header .tx-dot { background:#bce96c; }
+.console-split header span { color:#303836; font-size:12px; font-weight:600; }
+.console-split header small { margin-left:auto; color:#7d8683; font-size:10px; }
+.console-split pre {
+  height: min(55vh, 480px);
+  margin: 0;
+  padding: 14px;
+  overflow: auto;
+  border: 1px solid #d9ddda;
+  border-radius: 12px;
+  background: #171b1d;
+  color: #dce4e1;
+  font: 11px/1.45 Consolas, "SFMono-Regular", monospace;
+  white-space: pre-wrap;
+  overflow-wrap: anywhere;
+  user-select: text;
+}
+@media (max-width: 760px) {
+  .console-split { grid-template-columns:1fr; }
+  .console-split pre { height:220px; }
+}
+
 /* A pending or unknown armed state must stay legible, even without a link. */
 #engage.danger:disabled, #engage.pending:disabled { opacity:1 !important; }
 @media (prefers-reduced-motion: reduce) {
@@ -1131,3 +1216,85 @@ body:not([data-controls-enabled="true"]) .controls-grid { opacity:.65; }
   .telemetry-zone { gap:12px; }
   .activity-history { gap:4px; }
 }
+
+/* Settings windows: readable fields, predictable spacing, one action hierarchy. */
+.modal {
+  color-scheme: light;
+  width: min(560px, calc(100vw - 32px));
+  max-height: calc(100dvh - 32px);
+  padding: 28px;
+  overflow: auto;
+  overscroll-behavior: contain;
+  border: 1px solid #dedfdf;
+  border-radius: 20px;
+  background: #f6f6f6;
+  box-shadow: 0 24px 80px rgba(0,0,0,.24);
+  backdrop-filter: none;
+}
+.modal[open] { animation: dialog-in .16s ease-out; }
+.modal.closing { animation: dialog-out .12s ease-in forwards; }
+.modal::backdrop { background: rgba(15,19,22,.4); backdrop-filter: blur(3px); }
+.modal > small { display:block; color:#73787b; font-size:12px; font-weight:400; margin:0 42px 6px 0; }
+.modal h2 { margin:0 40px 18px 0; font-size:28px; letter-spacing:-.025em; font-weight:400; }
+.modal h3 { margin:0 0 10px; font-size:14px; font-weight:500; color:#454b4e; }
+.modal .note { font-size:13px; line-height:1.5; margin:8px 0 0; color:#676e71; }
+.modal-close { top:16px; right:16px; width:36px; height:36px; display:grid; place-items:center; border-radius:50%; background:#e9ebec; color:#555c60; font-size:25px; line-height:1; }
+.modal-close:hover { background:#dfe3e5; }
+.settings-section { margin-top:22px; }
+.settings-section + .settings-section { border-top:1px solid #e0e3e4; padding-top:20px; }
+.modal .form-grid { gap:16px; margin-top:10px; }
+.modal .form-grid.two { grid-template-columns:repeat(2,minmax(0,1fr)); }
+.modal label { min-width:0; font-size:13px; line-height:1.35; font-weight:400; color:#50585c; }
+.modal label > span { display:block; margin-bottom:7px; }
+.modal input,.modal select { width:100%; min-width:0; height:42px; padding:0 13px; border:1px solid #d7dcde; border-radius:999px; background:#fff; color:#272c2f; font-size:14px; font-weight:400; }
+.modal select { padding-right:28px; }
+.modal :is(button,input,select,summary,pre):focus-visible { outline:2px solid #6598b5; outline-offset:3px; }
+.modal .number-pill { height:42px; grid-template-columns:36px minmax(0,1fr) 36px; background:#fff; border:1px solid #d7dcde; }
+.modal .number-pill button { width:36px; height:40px; font-size:24px; color:#5b666b; }
+.modal .number-pill input { border:0; padding:0; height:40px; appearance:textfield; -moz-appearance:textfield; }
+.modal .number-pill input::-webkit-inner-spin-button { appearance:none; }
+.modal .number-pill:focus-within { border-color:#6598b5; }
+.custom-port-label { display:block; margin-top:16px; }
+.custom-port-row { display:flex; gap:8px; }
+.custom-port-row input { flex:1; }
+.modal .button { min-height:42px; height:auto; padding:10px 18px; font-size:14px; font-weight:400; border-radius:999px; white-space:normal; }
+.modal .button.subtle { background:#e9ebec; border:0; color:#424b50; }
+.modal .modal-primary { background:#333e44; color:#fff; border:0; }
+.modal .modal-primary:hover { background:#455660; }
+.modal .modal-actions { margin-top:24px; gap:10px; align-items:center; }
+.modal .form-feedback { margin:16px 0 0; padding:10px 12px; border-radius:12px; font-size:13px; line-height:1.5; color:#9b392e; background:#f5e6e3; }
+.modal [hidden] { display:none !important; }
+.modal [data-busy="true"] { cursor:progress; }
+.motor-modal { width:min(650px,calc(100vw - 32px)); }
+.modal .motor-head,.modal .motor-row { grid-template-columns:78px minmax(100px,1fr) 94px 86px; font-size:13px; gap:10px; padding:10px 0; }
+.modal .motor-head { margin-top:18px; color:#727b80; font-size:12px; font-weight:400; }
+.motor-row strong { font-size:12px; font-weight:500; }
+.motor-row > span { font-size:12px; color:#727b80; }
+.modal .motor-row .button { min-height:36px; font-size:12px; padding:8px 12px; }
+.motor-other { margin-top:16px; }
+.motor-other summary { cursor:pointer; padding:12px 0; color:#697278; font-size:13px; }
+.quality-summary { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:10px; margin-top:18px; }
+.quality-summary div { border-radius:14px; background:#e9ebec; padding:14px 12px; min-width:0; }
+.quality-summary span { display:block; font-size:12px; color:#697278; margin-bottom:8px; }
+.quality-summary strong { font-size:20px; font-weight:400; font-variant-numeric:tabular-nums; }
+.modal .heavy-quality-status { padding:12px; background:#e9ebec; border-radius:12px; font-size:14px; margin-top:14px; }
+.modal .heavy-result-row { font-size:13px; padding:10px 12px; font-variant-numeric:tabular-nums; }
+.console-modal { width:min(1020px,calc(100vw - 32px)); }
+.console-toolbar { display:flex; justify-content:space-between; align-items:center; gap:12px; }
+.console-toolbar .note { margin:0; }
+.modal .console-split header small { font-size:12px; }
+.modal .console-split pre { height:clamp(180px,48vh,430px); padding:14px; font-size:12px; line-height:1.55; border-radius:12px; }
+@keyframes dialog-in { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
+@keyframes dialog-out { to { opacity:0; transform:translateY(5px); } }
+@media (max-width:520px) {
+  .modal { padding:22px 18px; }
+  .modal .form-grid.two { grid-template-columns:1fr; }
+  .modal .motor-head,.modal .motor-row { grid-template-columns:56px minmax(80px,1fr) 74px 66px; gap:5px; font-size:12px; }
+  .modal .motor-row .button { padding:8px 6px; }
+  .quality-summary { gap:6px; }
+  .quality-summary div { padding:12px 8px; }
+  .quality-summary strong { font-size:17px; }
+}
+@media (prefers-reduced-motion:reduce) {
+  .modal[open],.modal.closing { animation:none; }
+}

web_ui.py

@@ -40,12 +40,15 @@ class ControlApi:
             "app_state": "disconnected",
             "status": "Ready. Select a USB port to begin.",
             "battery": None,
+            "link_quality": None,
+            "heavy_quality": None,
             "log_path": None,
             "servos": {str(i): {"function": None, "direction": None} for i in range(1, 17)},
         }
         self.servo_functions: dict[int, int] = {}
         self.motor_directions: dict[int, int] = {}
         self.battery_path = Path(__file__).resolve().parent / "battery_settings.json"
+        self.link_path = Path(__file__).resolve().parent / "link_settings.json"
         self.model_path = Path(__file__).resolve().parent / "model_settings.json"
         self.model_cache = Path(__file__).resolve().parent / "runtime" / "vehicle_model.stl"
         self.model_cache_name = Path(__file__).resolve().parent / "runtime" / "vehicle_model_name.txt"
@@ -62,11 +65,22 @@ class ControlApi:
             self.battery_config.update(json.loads(self.battery_path.read_text(encoding="utf-8")))
         except (OSError, ValueError, TypeError):
             pass
+        self.link_config = {
+            "baud": 57600, "control_hz": 20,
+            "ping_hz": 1, "system_hz": 1, "servo_hz": 2,
+            "rc_hz": 2, "esc_hz": 1,
+        }
+        try:
+            self.link_config.update(json.loads(self.link_path.read_text(encoding="utf-8")))
+        except (OSError, ValueError, TypeError):
+            pass
+        self._apply_link_config()
 
     def initial_state(self):
         return {
             "ports": self.refresh_ports(),
             "battery_config": self.battery_config,
+            "link_config": self.link_config,
             "state": self._snapshot(),
             "model_info": self.get_saved_model_info(),
         }
@@ -233,6 +247,9 @@ class ControlApi:
                 self.state.update(
                     connected=True, link="LINK OK", vehicle="DEMO • DISARMED",
                     armed=False, mode="MANUAL", status="Demo mode ready — no hardware connected.",
+                    link_quality={"grade": "excellent", "latency_ms": 12.0,
+                                  "loss_percent": 0.0, "samples": 20,
+                                  "corrupt_frames_20s": 0, "heartbeat_age_s": 0.1},
                     battery={"voltage": 15.8, "per_cell": 3.95, "percent": 72,
                              "cells": 4, "low": False},
                 )
@@ -268,15 +285,26 @@ class ControlApi:
         raise TimeoutError(f"No MAVLink heartbeat received from {port} within 8 seconds")
 
     def disconnect(self):
+        if self.worker.heavy_quality_test is not None:
+            self.worker.cancel_heavy_quality_test()
         if self.demo_mode:
             self.demo_mode = False
             with self.lock:
                 self.state.update(connected=False, link="DISCONNECTED", vehicle="No heartbeat",
-                                  armed=False, mode=None, battery=None, status="Demo mode disconnected")
+                                  armed=False, mode=None, battery=None, link_quality=None,
+                                  status="Demo mode disconnected")
             return True
         self.worker.disconnect()
         return True
 
+    def start_heavy_quality_test(self):
+        if self.demo_mode:
+            raise RuntimeError("The heavy link test requires a real flight-controller connection")
+        return self.worker.start_heavy_quality_test()
+
+    def cancel_heavy_quality_test(self):
+        return self.worker.cancel_heavy_quality_test()
+
     def set_axes(self, forward, turn, vertical, sequence=None):
         if self.demo_mode:
             with self.lock:
@@ -389,8 +417,33 @@ class ControlApi:
             raise ValueError("Full voltage per cell must be greater than empty voltage")
         if not 0 <= clean["warning_percent"] <= 100:
             raise ValueError("Warning percentage must be between 0 and 100")
-        self.battery_config = clean
         self.battery_path.write_text(json.dumps(clean, indent=2) + "\n", encoding="utf-8")
+        self.battery_config = clean
+        return clean
+
+    def _apply_link_config(self):
+        self.worker.rate_hz = self.link_config["control_hz"]
+        self.worker.set_link_rates(self.link_config["ping_hz"], {
+            "SYS_STATUS": self.link_config["system_hz"],
+            "SERVO_OUTPUT_RAW": self.link_config["servo_hz"],
+            "RC_CHANNELS": self.link_config["rc_hz"],
+            "ESC_TELEMETRY_1_TO_4": self.link_config["esc_hz"],
+        })
+
+    def save_link_settings(self, config):
+        allowed = {0, 1, 2, 5, 10}
+        clean = {key: int(config.get(key, value)) for key, value in self.link_config.items()}
+        if clean["baud"] not in {9600, 19200, 38400, 57600, 115200}:
+            raise ValueError("Choose a supported baud rate")
+        if clean["control_hz"] not in {10, 20}:
+            raise ValueError("Control rate must be 10 or 20 Hz")
+        if clean["ping_hz"] not in {1, 2, 5, 10}:
+            raise ValueError("Link test rate must be 1, 2, 5 or 10 Hz")
+        if any(clean[key] not in allowed for key in ("system_hz", "servo_hz", "rc_hz", "esc_hz")):
+            raise ValueError("Telemetry rates must be Off, 1, 2, 5 or 10 Hz")
+        self.link_path.write_text(json.dumps(clean, indent=2) + "\n", encoding="utf-8")
+        self.link_config = clean
+        self._apply_link_config()
         return clean
 
     def open_logs(self):
@@ -399,6 +452,10 @@ class ControlApi:
         os.startfile(path)
         return True
 
+    def read_console(self, limit=150):
+        """Return a bounded, read-only view of the local session console."""
+        return self.worker.read_console(limit)
+
     def poll(self):
         # Bound a poll even if telemetry arrives continuously.
         with self._poll_lock:
@@ -468,6 +525,10 @@ class ControlApi:
                     "voltage": voltage, "per_cell": per_cell, "percent": percent,
                     "cells": cells, "low": percent <= self.battery_config["warning_percent"],
                 }
+            elif kind == "link_quality":
+                self.state["link_quality"] = event[1]
+            elif kind == "heavy_quality":
+                self.state["heavy_quality"] = event[1]
             elif kind == "servo_param":
                 _, param_id, value = event
                 servo = int(param_id[5:param_id.index("_")])
@@ -490,7 +551,7 @@ class ControlApi:
                 last_err = self.state.get("last_error")
                 status_msg = last_err if last_err else "Disconnected"
                 self.state.update(connected=False, link="DISCONNECTED", vehicle="No heartbeat",
-                                  mode=None, status=status_msg)
+                                  mode=None, link_quality=None, status=status_msg)
                 self.state["last_error"] = None
 
     def _update_servo(self, servo):