feat: Add serial compass support #0

lib/models/device_info.dart

@@ -29,7 +29,7 @@ extension ConnectionModeExtension on ConnectionMode {
       case ConnectionMode.tcp:
         return 'Direct (WiFi)';
       case ConnectionMode.usb:
-        return 'Direct (USB)';
+        return 'Direct (Serial)';
     }
   }
 
@@ -40,7 +40,7 @@ extension ConnectionModeExtension on ConnectionMode {
       case ConnectionMode.tcp:
         return 'Direct WiFi/TCP connection to MeshCore device';
       case ConnectionMode.usb:
-        return 'USB serial connection to MeshCore device';
+        return 'Direct serial connection to MeshCore device';
     }
   }
 }

lib/providers/connection_provider.dart

@@ -73,6 +73,7 @@ class ConnectionProvider with ChangeNotifier {
   final MeshCoreBleService _bleService = MeshCoreBleService();
   MeshCoreTcpService? _tcpService;
   MeshCoreSerialService? _serialService;
+  Future<void> Function()? _serialDisconnectTransport;
 
   /// Expose BLE service for background location tracking
   MeshCoreBleService get bleService => _bleService;
@@ -246,7 +247,7 @@ class ConnectionProvider with ChangeNotifier {
     }
 
     if (activeMode != ConnectionMode.usb && _serialService != null) {
-      _disposeSerialService();
+      await _disposeSerialService();
     }
   }
 
@@ -260,10 +261,20 @@ class ConnectionProvider with ChangeNotifier {
     service.dispose();
   }
 
-  void _disposeSerialService() {
+  Future<void> _disposeSerialService() async {
-    _serialService?.markDisconnected();
+    final service = _serialService;
-    _serialService?.dispose();
+    final disconnectTransport = _serialDisconnectTransport;
     _serialService = null;
+    _serialDisconnectTransport = null;
+    if (service == null) {
+      return;
+    }
+    service.markDisconnected();
+    service.writeRaw = null;
+    if (disconnectTransport != null) {
+      await disconnectTransport();
+    }
+    service.dispose();
   }
 
   void _beginConnectionAttempt({
@@ -635,6 +646,13 @@ class ConnectionProvider with ChangeNotifier {
     debugPrint('✅ [Provider] Scan state initialized, notifying listeners');
 
     try {
+      final adapterError = await _awaitBleAdapterReady();
+      if (adapterError != null) {
+        debugPrint('⚠️ [Provider] BLE adapter not ready: $adapterError');
+        _error = adapterError;
+        return;
+      }
+
       await for (final scanResult in _bleService.scanForDevices(
         timeout: const Duration(seconds: 10),
       )) {
@@ -676,6 +694,53 @@ class ConnectionProvider with ChangeNotifier {
     }
   }
 
+  Future<String?> _awaitBleAdapterReady({
+    Duration timeout = const Duration(seconds: 4),
+  }) async {
+    if (!await FlutterBluePlus.isSupported) {
+      return 'Bluetooth is not supported on this device.';
+    }
+
+    var state = await FlutterBluePlus.adapterState.first;
+    debugPrint('🔵 [Provider] Initial BLE adapter state: $state');
+
+    if (state == BluetoothAdapterState.unknown ||
+        state == BluetoothAdapterState.turningOn) {
+      debugPrint('⏳ [Provider] Waiting for BLE adapter to finish initializing');
+      try {
+        state = await FlutterBluePlus.adapterState
+            .where(
+              (candidate) =>
+                  candidate != BluetoothAdapterState.unknown &&
+                  candidate != BluetoothAdapterState.turningOn,
+            )
+            .first
+            .timeout(timeout);
+      } on TimeoutException {
+        state = FlutterBluePlus.adapterStateNow;
+      }
+      debugPrint('🔵 [Provider] BLE adapter state after wait: $state');
+    }
+
+    if (state == BluetoothAdapterState.on) {
+      return null;
+    }
+
+    return switch (state) {
+      BluetoothAdapterState.off =>
+        'Bluetooth is turned off. Turn it on and try again.',
+      BluetoothAdapterState.turningOff =>
+        'Bluetooth is turning off. Turn it back on and try again.',
+      BluetoothAdapterState.unauthorized =>
+        'Bluetooth access is not allowed. Check app permissions in System Settings and try again.',
+      BluetoothAdapterState.unavailable =>
+        'Bluetooth hardware is unavailable. On macOS, verify Bluetooth access is enabled for this app target.',
+      BluetoothAdapterState.unknown || BluetoothAdapterState.turningOn =>
+        'Bluetooth is still initializing. Please try again in a moment.',
+      BluetoothAdapterState.on => null,
+    };
+  }
+
   /// Stop scanning
   Future<void> stopScan() async {
     await FlutterBluePlus.stopScan();
@@ -762,16 +827,22 @@ class ConnectionProvider with ChangeNotifier {
   /// The caller is responsible for opening the serial port and wiring
   /// [service.writeRaw] + [service.feedRawBytes] before calling this.
   /// After this call succeeds, [service.markConnected()] has already run.
-  Future<bool> connectSerial(MeshCoreSerialService service) async {
+  Future<bool> connectSerial({
+    required MeshCoreSerialService service,
+    required Future<void> Function() disconnectTransport,
+    required String deviceId,
+    required String deviceName,
+  }) async {
     debugPrint('🔌 [Provider] connectSerial()');
     await _prepareForConnectionSwitch(ConnectionMode.usb);
-    _disposeSerialService();
+    await _disposeSerialService();
     _serialService = service;
+    _serialDisconnectTransport = disconnectTransport;
     _wireServiceCallbacks(_serialService!);
     _beginConnectionAttempt(
       mode: ConnectionMode.usb,
-      deviceId: 'usb',
+      deviceId: deviceId,
-      deviceName: 'USB Companion',
+      deviceName: deviceName,
     );
 
     // markConnected() should already have been called by the transport.
@@ -780,6 +851,7 @@ class ConnectionProvider with ChangeNotifier {
       _deviceInfo = _deviceInfo.copyWith(
         connectionState: ConnectionState.error,
       );
+      await _disposeSerialService();
       notifyListeners();
       return false;
     }
@@ -788,7 +860,7 @@ class ConnectionProvider with ChangeNotifier {
 
   /// Disconnect from USB serial device.
   Future<void> disconnectSerial() async {
-    _disposeSerialService();
+    await _disposeSerialService();
     _resetConnectionSession();
   }
 
@@ -2771,6 +2843,12 @@ class ConnectionProvider with ChangeNotifier {
     _rxActivityTimer?.cancel();
     _txActivityTimer?.cancel();
     _stopAckCleanupTimer();
+    final disconnectTransport = _serialDisconnectTransport;
+    if (disconnectTransport != null) {
+      unawaited(disconnectTransport());
+      _serialDisconnectTransport = null;
+    }
+    _serialService?.dispose();
     _bleService.dispose();
     _tcpService?.dispose();
     super.dispose();

lib/screens/contacts_tab.dart

@@ -1551,14 +1551,12 @@ class _SectionHeader extends StatelessWidget {
   final int count;
   final IconData icon;
   final Color accentColor;
-  final Widget? trailing;
 
   const _SectionHeader({
     required this.title,
     required this.count,
     required this.icon,
     required this.accentColor,
-    this.trailing,
   });
 
   @override
@@ -1596,46 +1594,25 @@ class _SectionHeader extends StatelessWidget {
       ],
     );
 
-    return LayoutBuilder(
+    return Padding(
-      builder: (context, constraints) {
+      padding: const EdgeInsets.only(bottom: 12),
-        final useStackedLayout = trailing != null && constraints.maxWidth < 430;
+      child: Row(
-
+        children: [
-        return Padding(
+          Container(
-          padding: const EdgeInsets.only(bottom: 12),
+            width: 42,
-          child: Column(
+            height: 42,
-            crossAxisAlignment: CrossAxisAlignment.start,
+            decoration: BoxDecoration(
-            children: [
+              color: accentColor.withValues(alpha: 0.12),
-              Row(
+              borderRadius: BorderRadius.circular(14),
-                children: [
+              border: Border.all(color: accentColor.withValues(alpha: 0.18)),
-                  Container(
+            ),
-                    width: 42,
+            alignment: Alignment.center,
-                    height: 42,
+            child: Icon(icon, size: 20, color: accentColor),
-                    decoration: BoxDecoration(
-                      color: accentColor.withValues(alpha: 0.12),
-                      borderRadius: BorderRadius.circular(14),
-                      border: Border.all(
-                        color: accentColor.withValues(alpha: 0.18),
-                      ),
-                    ),
-                    alignment: Alignment.center,
-                    child: Icon(icon, size: 20, color: accentColor),
-                  ),
-                  const SizedBox(width: 12),
-                  Expanded(child: titleBlock),
-                  if (!useStackedLayout && trailing != null) ...[
-                    const SizedBox(width: 12),
-                    Flexible(child: trailing!),
-                  ],
-                ],
-              ),
-              if (useStackedLayout) ...[
-                const SizedBox(height: 10),
-                Align(alignment: Alignment.centerRight, child: trailing!),
-              ],
-            ],
           ),
-        );
+          const SizedBox(width: 12),
-      },
+          Expanded(child: titleBlock),
+        ],
+      ),
     );
   }
 }

lib/services/serial/serial_transport.dart

@@ -0,0 +1,50 @@
+import 'package:meshcore_client/meshcore_client.dart';
+
+import 'serial_transport_stub.dart'
+    if (dart.library.io) 'serial_transport_io.dart'
+    if (dart.library.js_interop) 'serial_transport_web.dart';
+
+const int kSerialBaudRate = 115200;
+
+class SerialDeviceInfo {
+  final String id;
+  final String title;
+  final String subtitle;
+  final Object handle;
+
+  const SerialDeviceInfo({
+    required this.id,
+    required this.title,
+    required this.subtitle,
+    required this.handle,
+  });
+}
+
+class SerialConnection {
+  final MeshCoreSerialService service;
+  final String deviceId;
+  final String deviceName;
+  final Future<void> Function() disconnect;
+
+  const SerialConnection({
+    required this.service,
+    required this.deviceId,
+    required this.deviceName,
+    required this.disconnect,
+  });
+}
+
+abstract class SerialTransport {
+  bool get isSupported;
+  bool get canRequestDevice;
+  String get actionLabel;
+  String get emptyStateTitle;
+  String get unsupportedMessage;
+
+  Future<List<SerialDeviceInfo>> listDevices();
+  Future<SerialDeviceInfo?> requestDevice();
+  Future<SerialConnection> connect(SerialDeviceInfo device);
+  void dispose();
+}
+
+SerialTransport createSerialTransport() => createSerialTransportImpl();

lib/services/serial/serial_transport_io.dart

@@ -0,0 +1,283 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter_libserialport/flutter_libserialport.dart';
+import 'package:meshcore_client/meshcore_client.dart';
+import 'package:usb_serial/usb_serial.dart';
+
+import 'serial_transport.dart';
+
+class _IoSerialTransport implements SerialTransport {
+  @override
+  bool get isSupported =>
+      Platform.isAndroid || Platform.isMacOS || Platform.isWindows;
+
+  @override
+  bool get canRequestDevice => false;
+
+  @override
+  String get actionLabel =>
+      Platform.isAndroid ? 'Scan USB devices' : 'Scan serial ports';
+
+  @override
+  String get emptyStateTitle => Platform.isAndroid
+      ? 'No USB serial devices found.\nConnect a MeshCore device via OTG cable.'
+      : 'No serial ports found.\nConnect a MeshCore device over USB serial.';
+
+  @override
+  String get unsupportedMessage =>
+      'Serial is supported on Android, macOS, Windows, and compatible web browsers.';
+
+  @override
+  Future<List<SerialDeviceInfo>> listDevices() async {
+    if (Platform.isAndroid) {
+      final devices = await UsbSerial.listDevices();
+      return devices.map(_androidDeviceInfo).toList(growable: false);
+    }
+    if (Platform.isMacOS || Platform.isWindows) {
+      return _desktopSerialDevices();
+    }
+    return const [];
+  }
+
+  @override
+  Future<SerialDeviceInfo?> requestDevice() async => null;
+
+  @override
+  Future<SerialConnection> connect(SerialDeviceInfo device) async {
+    if (Platform.isAndroid) {
+      return _connectAndroid(device);
+    }
+    if (Platform.isMacOS || Platform.isWindows) {
+      return _connectDesktop(device);
+    }
+    throw UnsupportedError(unsupportedMessage);
+  }
+
+  SerialDeviceInfo _androidDeviceInfo(UsbDevice device) {
+    final title = _firstNonEmpty([
+      device.productName,
+      device.manufacturerName,
+      'USB Serial Device',
+    ]);
+    final subtitleParts = <String>[
+      if ((device.manufacturerName ?? '').trim().isNotEmpty)
+        device.manufacturerName!.trim(),
+      if (device.vid != null && device.pid != null)
+        'VID:${_hex(device.vid!)} PID:${_hex(device.pid!)}',
+    ];
+
+    return SerialDeviceInfo(
+      id: '${device.deviceId}:${device.vid ?? 'na'}:${device.pid ?? 'na'}:${device.productName ?? 'usb'}',
+      title: title,
+      subtitle: subtitleParts.isEmpty
+          ? 'Ready over OTG serial'
+          : subtitleParts.join(' • '),
+      handle: device,
+    );
+  }
+
+  Future<List<SerialDeviceInfo>> _desktopSerialDevices() async {
+    final ports = <SerialDeviceInfo>[];
+    for (final address in SerialPort.availablePorts) {
+      final port = SerialPort(address);
+      try {
+        final title = _firstNonEmpty([
+          port.productName,
+          port.description,
+          address,
+        ]);
+        final subtitleParts = <String>[
+          address,
+          if ((port.manufacturer ?? '').trim().isNotEmpty)
+            port.manufacturer!.trim(),
+          if (port.vendorId != null && port.productId != null)
+            'VID:${_hex(port.vendorId!)} PID:${_hex(port.productId!)}',
+        ];
+        ports.add(
+          SerialDeviceInfo(
+            id: address,
+            title: title,
+            subtitle: subtitleParts.join(' • '),
+            handle: address,
+          ),
+        );
+      } finally {
+        port.dispose();
+      }
+    }
+    return ports;
+  }
+
+  Future<SerialConnection> _connectAndroid(SerialDeviceInfo device) async {
+    final usbDevice = device.handle as UsbDevice;
+    final service = MeshCoreSerialService(appName: 'MeshCore SAR');
+    StreamSubscription<Uint8List>? inputSubscription;
+    UsbPort? port;
+
+    try {
+      port = await usbDevice.create();
+      if (port == null) {
+        throw Exception('Failed to create USB port');
+      }
+      final opened = await port.open();
+      if (!opened) {
+        throw Exception('Failed to open USB port');
+      }
+
+      await port.setDTR(true);
+      await port.setRTS(true);
+      await port.setPortParameters(
+        kSerialBaudRate,
+        UsbPort.DATABITS_8,
+        UsbPort.STOPBITS_1,
+        UsbPort.PARITY_NONE,
+      );
+
+      service.writeRaw = (data) async {
+        await port!.write(data);
+      };
+
+      inputSubscription = port.inputStream?.listen(
+        (data) => service.feedRawBytes(data),
+        onError: (error) {
+          debugPrint('❌ [Serial/Android] Read error: $error');
+          service.markDisconnected();
+        },
+        onDone: () {
+          debugPrint('⚠️ [Serial/Android] Port closed');
+          service.markDisconnected();
+        },
+      );
+
+      final connected = await service.markConnected();
+      if (!connected) {
+        throw Exception('Serial session initialization failed');
+      }
+
+      return SerialConnection(
+        service: service,
+        deviceId:
+            '${usbDevice.deviceId}:${usbDevice.vid ?? 'na'}:${usbDevice.pid ?? 'na'}',
+        deviceName: device.title,
+        disconnect: () async {
+          await inputSubscription?.cancel();
+          inputSubscription = null;
+          service.writeRaw = null;
+          await port?.close();
+          port = null;
+        },
+      );
+    } catch (_) {
+      await inputSubscription?.cancel();
+      service.writeRaw = null;
+      await port?.close();
+      service.dispose();
+      rethrow;
+    }
+  }
+
+  Future<SerialConnection> _connectDesktop(SerialDeviceInfo device) async {
+    final portName = device.handle as String;
+    final port = SerialPort(portName);
+    final config = SerialPortConfig();
+    final service = MeshCoreSerialService(appName: 'MeshCore SAR');
+    SerialPortReader? reader;
+    StreamSubscription<Uint8List>? inputSubscription;
+
+    try {
+      if (!port.openReadWrite()) {
+        throw Exception(
+          SerialPort.lastError?.message ?? 'Failed to open serial port',
+        );
+      }
+
+      config.baudRate = kSerialBaudRate;
+      config.bits = 8;
+      config.stopBits = 1;
+      config.parity = SerialPortParity.none;
+      config.setFlowControl(SerialPortFlowControl.none);
+      config.dtr = SerialPortDtr.on;
+      config.rts = SerialPortRts.on;
+      port.config = config;
+
+      service.writeRaw = (data) async {
+        var offset = 0;
+        while (offset < data.length) {
+          final written = port.write(data.sublist(offset));
+          if (written <= 0) {
+            throw Exception(
+              SerialPort.lastError?.message ?? 'Failed to write to serial port',
+            );
+          }
+          offset += written;
+        }
+      };
+
+      reader = SerialPortReader(port);
+      inputSubscription = reader.stream.listen(
+        (data) => service.feedRawBytes(data),
+        onError: (error) {
+          debugPrint('❌ [Serial/Desktop] Read error: $error');
+          service.markDisconnected();
+        },
+        onDone: () {
+          debugPrint('⚠️ [Serial/Desktop] Reader closed');
+          service.markDisconnected();
+        },
+      );
+
+      final connected = await service.markConnected();
+      if (!connected) {
+        throw Exception('Serial session initialization failed');
+      }
+
+      return SerialConnection(
+        service: service,
+        deviceId: portName,
+        deviceName: device.title,
+        disconnect: () async {
+          await inputSubscription?.cancel();
+          inputSubscription = null;
+          reader?.close();
+          reader = null;
+          service.writeRaw = null;
+          if (port.isOpen) {
+            port.close();
+          }
+          port.dispose();
+          config.dispose();
+        },
+      );
+    } catch (_) {
+      await inputSubscription?.cancel();
+      reader?.close();
+      service.writeRaw = null;
+      if (port.isOpen) {
+        port.close();
+      }
+      port.dispose();
+      config.dispose();
+      service.dispose();
+      rethrow;
+    }
+  }
+
+  @override
+  void dispose() {}
+}
+
+String _firstNonEmpty(List<String?> values) {
+  for (final value in values) {
+    final trimmed = value?.trim();
+    if (trimmed != null && trimmed.isNotEmpty) {
+      return trimmed;
+    }
+  }
+  return 'Serial Device';
+}
+
+String _hex(int value) => value.toRadixString(16).padLeft(4, '0');
+
+SerialTransport createSerialTransportImpl() => _IoSerialTransport();

lib/services/serial/serial_transport_stub.dart

@@ -0,0 +1,35 @@
+import 'serial_transport.dart';
+
+class _UnsupportedSerialTransport implements SerialTransport {
+  @override
+  bool get isSupported => false;
+
+  @override
+  bool get canRequestDevice => false;
+
+  @override
+  String get actionLabel => 'Serial unsupported';
+
+  @override
+  String get emptyStateTitle => 'Serial is unavailable on this platform.';
+
+  @override
+  String get unsupportedMessage =>
+      'Serial is supported on Android, macOS, Windows, and compatible web browsers.';
+
+  @override
+  Future<List<SerialDeviceInfo>> listDevices() async => const [];
+
+  @override
+  Future<SerialDeviceInfo?> requestDevice() async => null;
+
+  @override
+  Future<SerialConnection> connect(SerialDeviceInfo device) async {
+    throw UnsupportedError(unsupportedMessage);
+  }
+
+  @override
+  void dispose() {}
+}
+
+SerialTransport createSerialTransportImpl() => _UnsupportedSerialTransport();

lib/services/serial/serial_transport_web.dart

@@ -0,0 +1,209 @@
+import 'dart:async';
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
+
+import 'package:meshcore_client/meshcore_client.dart';
+import 'package:web/web.dart' as web;
+import 'package:webserial/webserial.dart';
+
+import 'serial_transport.dart';
+
+class _WebSerialTransport implements SerialTransport {
+  @override
+  bool get isSupported =>
+      web.window.navigator.hasProperty('serial'.toJS).toDart;
+
+  @override
+  bool get canRequestDevice => true;
+
+  @override
+  String get actionLabel => 'Choose serial device';
+
+  @override
+  String get emptyStateTitle =>
+      'No serial devices granted yet.\nChoose a device and approve access in your browser.';
+
+  @override
+  String get unsupportedMessage =>
+      'Web Serial requires a compatible browser such as Chrome or Edge and a secure context (HTTPS or localhost).';
+
+  @override
+  Future<List<SerialDeviceInfo>> listDevices() async {
+    if (!isSupported) {
+      return const [];
+    }
+    final ports = await serial.getPorts().toDart;
+    return ports
+        .toDart
+        .whereType<JSSerialPort>()
+        .map(_deviceInfoForPort)
+        .toList(growable: false);
+  }
+
+  @override
+  Future<SerialDeviceInfo?> requestDevice() async {
+    if (!isSupported) {
+      return null;
+    }
+    final port = await requestWebSerialPort(null);
+    if (port == null) {
+      return null;
+    }
+    return _deviceInfoForPort(port);
+  }
+
+  @override
+  Future<SerialConnection> connect(SerialDeviceInfo device) async {
+    final port = device.handle as JSSerialPort;
+    final service = MeshCoreSerialService(appName: 'MeshCore SAR');
+    web.ReadableStreamDefaultReader? reader;
+    bool keepReading = false;
+
+    try {
+      await port
+          .open(
+            JSSerialOptions(
+              baudRate: kSerialBaudRate,
+              dataBits: 8,
+              stopBits: 1,
+              parity: 'none',
+              bufferSize: 1024,
+              flowControl: 'none',
+            ),
+          )
+          .toDart;
+
+      await port
+          .setSignals(
+            JSSerialOutputSignals(
+              dataTerminalReady: true,
+              requestToSend: true,
+            ),
+          )
+          .toDart;
+
+      service.writeRaw = (data) async {
+        final writable = port.writable;
+        if (writable == null) {
+          throw Exception('Serial port is not writable');
+        }
+        final writer =
+            writable.getWriter() as web.WritableStreamDefaultWriter?;
+        if (writer == null) {
+          throw Exception('Failed to acquire serial writer');
+        }
+        try {
+          await writer.write(data.toJS).toDart;
+        } finally {
+          writer.releaseLock();
+        }
+      };
+
+      final readable = port.readable;
+      if (readable == null) {
+        throw Exception('Serial port is not readable');
+      }
+
+      reader = readable.getReader() as web.ReadableStreamDefaultReader?;
+      if (reader == null) {
+        throw Exception('Failed to acquire serial reader');
+      }
+
+      keepReading = true;
+      unawaited(_readLoop(reader, service, () => keepReading));
+
+      final connected = await service.markConnected();
+      if (!connected) {
+        throw Exception('Serial session initialization failed');
+      }
+
+      return SerialConnection(
+        service: service,
+        deviceId: device.id,
+        deviceName: device.title,
+        disconnect: () async {
+          keepReading = false;
+          try {
+            await reader?.cancel().toDart;
+          } catch (_) {}
+          try {
+            reader?.releaseLock();
+          } catch (_) {}
+          reader = null;
+          service.writeRaw = null;
+          try {
+            await port.close().toDart;
+          } catch (_) {}
+        },
+      );
+    } catch (_) {
+      keepReading = false;
+      try {
+        await reader?.cancel().toDart;
+      } catch (_) {}
+      try {
+        reader?.releaseLock();
+      } catch (_) {}
+      service.writeRaw = null;
+      try {
+        await port.close().toDart;
+      } catch (_) {}
+      service.dispose();
+      rethrow;
+    }
+  }
+
+  Future<void> _readLoop(
+    web.ReadableStreamDefaultReader reader,
+    MeshCoreSerialService service,
+    bool Function() shouldContinue,
+  ) async {
+    while (shouldContinue()) {
+      try {
+        final result = await reader.read().toDart;
+        if (result.done) {
+          break;
+        }
+        final value = result.value;
+        if (value == null) {
+          continue;
+        }
+        service.feedRawBytes((value as JSUint8Array).toDart);
+      } catch (_) {
+        break;
+      }
+    }
+    service.markDisconnected();
+    try {
+      reader.releaseLock();
+    } catch (_) {}
+  }
+
+  SerialDeviceInfo _deviceInfoForPort(JSSerialPort port) {
+    final info = port.getInfo();
+    final vendorId = info.usbVendorId;
+    final productId = info.usbProductId;
+    final title = (vendorId != 0 || productId != 0)
+        ? 'USB ${_hex(vendorId)}:${_hex(productId)}'
+        : 'Granted serial device';
+    final subtitle = [
+      if (vendorId != 0 || productId != 0)
+        'VID:${_hex(vendorId)} PID:${_hex(productId)}',
+      'Web Serial',
+    ].join(' • ');
+
+    return SerialDeviceInfo(
+      id: '$title::$subtitle',
+      title: title,
+      subtitle: subtitle,
+      handle: port,
+    );
+  }
+
+  @override
+  void dispose() {}
+}
+
+String _hex(int value) => value.toRadixString(16).padLeft(4, '0');
+
+SerialTransport createSerialTransportImpl() => _WebSerialTransport();

lib/widgets/connection_dialog.dart

@@ -1,13 +1,11 @@
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:meshcore_client/meshcore_client.dart' hide Contact;
 import 'package:provider/provider.dart';
-import 'package:usb_serial/usb_serial.dart';
 
 import '../l10n/app_localizations.dart';
 import '../providers/app_provider.dart';
 import '../providers/connection_provider.dart';
 import '../services/network_scanner_service.dart';
+import '../services/serial/serial_transport.dart';
 
 /// Connection Dialog with tabs for BLE devices and Network servers
 class ConnectionDialog extends StatefulWidget {
@@ -166,7 +164,7 @@ class _ConnectionDialogState extends State<ConnectionDialog>
                           ),
                           const SizedBox(height: 2),
                           Text(
-                            'Choose Bluetooth, WiFi, or USB transport',
+                            'Choose Bluetooth, WiFi, or Serial transport',
                             textAlign: TextAlign.center,
                             style: theme.textTheme.bodySmall?.copyWith(
                               color: theme.colorScheme.onSurfaceVariant,
@@ -192,7 +190,7 @@ class _ConnectionDialogState extends State<ConnectionDialog>
                   tabs: const [
                     Tab(text: 'BLE', icon: Icon(Icons.bluetooth_rounded)),
                     Tab(text: 'Network', icon: Icon(Icons.wifi_rounded)),
-                    Tab(text: 'USB', icon: Icon(Icons.usb_rounded)),
+                    Tab(text: 'Serial', icon: Icon(Icons.usb_rounded)),
                   ],
                 ),
               ],
@@ -250,6 +248,36 @@ class _ConnectionDialogState extends State<ConnectionDialog>
     );
   }
 
+  Widget _buildErrorBanner(String message) {
+    final theme = Theme.of(context);
+    return Container(
+      margin: const EdgeInsets.fromLTRB(16, 0, 16, 12),
+      padding: const EdgeInsets.all(14),
+      decoration: BoxDecoration(
+        color: theme.colorScheme.errorContainer,
+        borderRadius: BorderRadius.circular(16),
+      ),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Icon(
+            Icons.error_outline_rounded,
+            color: theme.colorScheme.onErrorContainer,
+          ),
+          const SizedBox(width: 10),
+          Expanded(
+            child: Text(
+              message,
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onErrorContainer,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
   Widget _buildEmptyState({
     required IconData icon,
     required String title,
@@ -371,6 +399,8 @@ class _ConnectionDialogState extends State<ConnectionDialog>
           message: AppLocalizations.of(context)!.defaultPinInfo,
           onRefresh: _refreshBleDevices,
         ),
+        if (connectionProvider.error != null)
+          _buildErrorBanner(connectionProvider.error!),
         Expanded(
           child:
               connectionProvider.isScanning &&
@@ -597,7 +627,7 @@ class _ConnectionDialogState extends State<ConnectionDialog>
   }
 
   Widget _buildUsbTab() {
-    return _UsbDeviceList(
+    return _SerialDeviceList(
       buildTransportCard:
           ({
             required icon,
@@ -654,38 +684,48 @@ typedef _EmptyStateBuilder =
       required VoidCallback onAction,
     });
 
-class _UsbDeviceList extends StatefulWidget {
+class _SerialDeviceList extends StatefulWidget {
   final VoidCallback onConnected;
   final _TransportCardBuilder buildTransportCard;
   final _EmptyStateBuilder buildEmptyState;
 
-  const _UsbDeviceList({
+  const _SerialDeviceList({
     required this.onConnected,
     required this.buildTransportCard,
     required this.buildEmptyState,
   });
 
   @override
-  State<_UsbDeviceList> createState() => _UsbDeviceListState();
+  State<_SerialDeviceList> createState() => _SerialDeviceListState();
 }
 
-class _UsbDeviceListState extends State<_UsbDeviceList> {
+class _SerialDeviceListState extends State<_SerialDeviceList> {
-  List<UsbDevice> _devices = [];
+  final SerialTransport _transport = createSerialTransport();
+  List<SerialDeviceInfo> _devices = [];
   bool _isScanning = false;
   bool _isConnecting = false;
 
   @override
   void initState() {
     super.initState();
-    if (defaultTargetPlatform == TargetPlatform.android) {
+    if (_transport.isSupported) {
       _scanDevices();
     }
   }
 
+  @override
+  void dispose() {
+    _transport.dispose();
+    super.dispose();
+  }
+
   Future<void> _scanDevices() async {
+    if (!_transport.isSupported) {
+      return;
+    }
     setState(() => _isScanning = true);
     try {
-      final devices = await UsbSerial.listDevices();
+      final devices = await _transport.listDevices();
       if (!mounted) return;
       setState(() {
         _devices = devices;
@@ -700,81 +740,66 @@ class _UsbDeviceListState extends State<_UsbDeviceList> {
     }
   }
 
-  Future<void> _connectToDevice(UsbDevice device) async {
+  Future<void> _requestDevice() async {
+    if (!_transport.canRequestDevice) {
+      await _scanDevices();
+      return;
+    }
+
+    setState(() => _isScanning = true);
+    try {
+      final selectedDevice = await _transport.requestDevice();
+      final devices = await _transport.listDevices();
+      if (!mounted) return;
+      setState(() {
+        _devices = selectedDevice == null
+            ? devices
+            : _mergeDevices(devices, selectedDevice);
+        _isScanning = false;
+      });
+    } catch (_) {
+      if (!mounted) return;
+      setState(() {
+        _isScanning = false;
+      });
+    }
+  }
+
+  List<SerialDeviceInfo> _mergeDevices(
+    List<SerialDeviceInfo> devices,
+    SerialDeviceInfo selectedDevice,
+  ) {
+    final merged = [...devices];
+    if (!merged.any((device) => device.id == selectedDevice.id)) {
+      merged.insert(0, selectedDevice);
+    }
+    return merged;
+  }
+
+  Future<void> _connectToDevice(SerialDeviceInfo device) async {
     setState(() => _isConnecting = true);
     try {
       final connectionProvider = context.read<ConnectionProvider>();
-      final service = MeshCoreSerialService(appName: 'MeshCore SAR');
+      final appProvider = context.read<AppProvider>();
-
+      final connection = await _transport.connect(device);
-      final port = await device.create();
+      final success = await connectionProvider.connectSerial(
-      if (port == null) {
+        service: connection.service,
-        if (mounted) {
+        disconnectTransport: connection.disconnect,
-          setState(() => _isConnecting = false);
+        deviceId: connection.deviceId,
-          ScaffoldMessenger.of(context).showSnackBar(
+        deviceName: connection.deviceName,
-            const SnackBar(content: Text('Failed to create USB port')),
-          );
-        }
-        return;
-      }
-
-      final opened = await port.open();
-      if (!opened) {
-        if (mounted) {
-          setState(() => _isConnecting = false);
-          ScaffoldMessenger.of(context).showSnackBar(
-            const SnackBar(content: Text('Failed to open USB port')),
-          );
-        }
-        return;
-      }
-
-      await port.setDTR(true);
-      await port.setRTS(true);
-      await port.setPortParameters(
-        115200,
-        UsbPort.DATABITS_8,
-        UsbPort.STOPBITS_1,
-        UsbPort.PARITY_NONE,
       );
-
-      service.writeRaw = (data) async {
-        await port.write(data);
-      };
-
-      port.inputStream?.listen(
-        (data) => service.feedRawBytes(data),
-        onError: (_) {
-          service.markDisconnected();
-          port.close();
-        },
-        onDone: () {
-          service.markDisconnected();
-        },
-      );
-
-      final sessionOk = await service.markConnected();
-      if (!sessionOk) {
-        await port.close();
-        if (mounted) {
-          setState(() => _isConnecting = false);
-          ScaffoldMessenger.of(context).showSnackBar(
-            const SnackBar(content: Text('USB session initialization failed')),
-          );
-        }
-        return;
-      }
-
-      final success = await connectionProvider.connectSerial(service);
       if (!mounted) return;
 
       if (success) {
+        await appProvider.initialize();
         widget.onConnected();
       } else {
-        await port.close();
+        await connection.disconnect();
+        connection.service.dispose();
         if (!mounted) return;
         setState(() => _isConnecting = false);
         ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('Failed to connect via USB')),
+          const SnackBar(content: Text('Failed to connect via serial')),
         );
       }
     } catch (e) {
@@ -782,20 +807,18 @@ class _UsbDeviceListState extends State<_UsbDeviceList> {
       setState(() => _isConnecting = false);
       ScaffoldMessenger.of(
         context,
-      ).showSnackBar(SnackBar(content: Text('USB error: $e')));
+      ).showSnackBar(SnackBar(content: Text('Serial error: $e')));
     }
   }
 
   @override
   Widget build(BuildContext context) {
-    if (defaultTargetPlatform != TargetPlatform.android) {
+    if (!_transport.isSupported) {
       return Center(
         child: Padding(
           padding: const EdgeInsets.all(24),
           child: Text(
-            kIsWeb
+            _transport.unsupportedMessage,
-                ? 'Web Serial is not yet supported.\nUse BLE or Network instead.'
-                : 'USB serial is available on Android only.\nConnect via OTG cable.',
             textAlign: TextAlign.center,
           ),
         ),
@@ -811,19 +834,22 @@ class _UsbDeviceListState extends State<_UsbDeviceList> {
         Padding(
           padding: const EdgeInsets.fromLTRB(16, 16, 16, 8),
           child: FilledButton.tonalIcon(
-            onPressed: _isConnecting ? null : _scanDevices,
+            onPressed: _isConnecting
+                ? null
+                : (_transport.canRequestDevice ? _requestDevice : _scanDevices),
             icon: const Icon(Icons.usb_rounded),
-            label: const Text('Scan USB devices'),
+            label: Text(_transport.actionLabel),
           ),
         ),
         if (_devices.isEmpty)
           Expanded(
             child: widget.buildEmptyState(
               icon: Icons.usb_off_rounded,
-              title:
+              title: _transport.emptyStateTitle,
-                  'No USB serial devices found.\nConnect a MeshCore device via OTG cable.',
+              actionLabel: _transport.actionLabel,
-              actionLabel: 'Scan USB devices',
+              onAction: _transport.canRequestDevice
-              onAction: _scanDevices,
+                  ? _requestDevice
+                  : _scanDevices,
             ),
           )
         else
@@ -835,10 +861,8 @@ class _UsbDeviceListState extends State<_UsbDeviceList> {
                 return widget.buildTransportCard(
                   icon: Icons.usb_rounded,
                   iconColor: Theme.of(context).colorScheme.primary,
-                  title: device.productName ?? 'USB Device',
+                  title: device.title,
-                  subtitle: (device.manufacturerName?.isNotEmpty ?? false)
+                  subtitle: device.subtitle,
-                      ? device.manufacturerName!
-                      : 'Ready over OTG serial',
                   trailing: _isConnecting
                       ? const SizedBox(
                           width: 24,

lib/widgets/map/compass/compass_header.dart

@@ -6,6 +6,7 @@ import 'package:latlong2/latlong.dart';
 import '../../../l10n/app_localizations.dart';
 import '../../../models/contact.dart';
 import '../../../models/sar_marker.dart';
+import 'compass_math.dart';
 
 /// Header component for the compass dialog showing compass rose,
 /// heading, elevation, accuracy, and current location in multiple formats.
@@ -76,7 +77,11 @@ class CompassHeader extends StatelessWidget {
     );
   }
 
-  Widget _buildInfoRow(BuildContext context, double? heading, Position? position) {
+  Widget _buildInfoRow(
+    BuildContext context,
+    double? heading,
+    Position? position,
+  ) {
     final l10n = AppLocalizations.of(context)!;
     return Row(
       mainAxisAlignment: MainAxisAlignment.spaceAround,
@@ -90,17 +95,13 @@ class CompassHeader extends StatelessWidget {
         _buildInfoCard(
           context,
           l10n.elevation,
-          position?.altitude != null
+          position?.altitude != null ? '${position!.altitude.round()}m' : '--',
-              ? '${position!.altitude.round()}m'
-              : '--',
           Icons.terrain,
         ),
         _buildInfoCard(
           context,
           l10n.accuracy,
-          position?.accuracy != null
+          position?.accuracy != null ? '±${position!.accuracy.round()}m' : '--',
-              ? '±${position!.accuracy.round()}m'
-              : '--',
           Icons.gps_fixed,
         ),
       ],
@@ -108,21 +109,22 @@ class CompassHeader extends StatelessWidget {
   }
 
   Widget _buildInfoCard(
-      BuildContext context, String label, String value, IconData icon) {
+    BuildContext context,
+    String label,
+    String value,
+    IconData icon,
+  ) {
     return Column(
       children: [
         Icon(icon, size: 20, color: Theme.of(context).colorScheme.primary),
         const SizedBox(height: 4),
         Text(
           value,
-          style: Theme.of(context).textTheme.titleMedium?.copyWith(
+          style: Theme.of(
-                fontWeight: FontWeight.bold,
+            context,
-              ),
+          ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.bold),
-        ),
-        Text(
-          label,
-          style: Theme.of(context).textTheme.bodySmall,
         ),
+        Text(label, style: Theme.of(context).textTheme.bodySmall),
       ],
     );
   }
@@ -193,11 +195,16 @@ class _LargeCompassPainter extends CustomPainter {
 
     // Draw degree markers
     for (int i = 0; i < 360; i += 10) {
-      final angle = i * pi / 180 - pi / 2 + heading * pi / 180;
+      final angle = compassDialAngleRadians(
+        markerDegrees: i.toDouble(),
+        headingDegrees: heading,
+      );
       final isCardinal = i % 90 == 0;
       final isMajor = i % 30 == 0;
 
-      final startRadius = isCardinal ? radius - 25 : (isMajor ? radius - 15 : radius - 10);
+      final startRadius = isCardinal
+          ? radius - 25
+          : (isMajor ? radius - 15 : radius - 10);
       final start = Offset(
         center.dx + startRadius * cos(angle),
         center.dy + startRadius * sin(angle),
@@ -218,7 +225,10 @@ class _LargeCompassPainter extends CustomPainter {
     final textPainter = TextPainter(textDirection: TextDirection.ltr);
     final directions = ['N', 'E', 'S', 'W'];
     for (int i = 0; i < 4; i++) {
-      final angle = i * pi / 2 - pi / 2 + heading * pi / 180;
+      final angle = compassDialAngleRadians(
+        markerDegrees: (i * 90).toDouble(),
+        headingDegrees: heading,
+      );
       final x = center.dx + (radius - 35) * cos(angle);
       final y = center.dy + (radius - 35) * sin(angle);
 
@@ -243,20 +253,25 @@ class _LargeCompassPainter extends CustomPainter {
       final contactsWithDistance = contacts
           .where((c) => c.displayLocation != null)
           .map((contact) {
-        final bearing = _calculateBearing(
+            final bearing = _calculateBearing(
-          currentPosition!.latitude,
+              currentPosition!.latitude,
-          currentPosition!.longitude,
+              currentPosition!.longitude,
-          contact.displayLocation!.latitude,
+              contact.displayLocation!.latitude,
-          contact.displayLocation!.longitude,
+              contact.displayLocation!.longitude,
-        );
+            );
-        final distance = _calculateDistance(
+            final distance = _calculateDistance(
-          currentPosition!.latitude,
+              currentPosition!.latitude,
-          currentPosition!.longitude,
+              currentPosition!.longitude,
-          contact.displayLocation!.latitude,
+              contact.displayLocation!.latitude,
-          contact.displayLocation!.longitude,
+              contact.displayLocation!.longitude,
-        );
+            );
-        return {'contact': contact, 'bearing': bearing, 'distance': distance};
+            return {
-      }).toList();
+              'contact': contact,
+              'bearing': bearing,
+              'distance': distance,
+            };
+          })
+          .toList();
 
       if (contactsWithDistance.isEmpty) return;
 
@@ -277,7 +292,8 @@ class _LargeCompassPainter extends CustomPainter {
         double normalizedDistance = (distance / baseDistance).clamp(0.0, 1.0);
 
         // Calculate contact position radius (from center to rim based on distance)
-        final contactRadius = radius * normalizedDistance * 0.85; // 0.85 to keep inside rim
+        final contactRadius =
+            radius * normalizedDistance * 0.85; // 0.85 to keep inside rim
 
         // Position of contact dot
         final dotX = center.dx + contactRadius * cos(angle);
@@ -288,11 +304,7 @@ class _LargeCompassPainter extends CustomPainter {
           ..color = Colors.lightBlue.withValues(alpha: 0.3)
           ..style = PaintingStyle.stroke
           ..strokeWidth = 1.5;
-        canvas.drawLine(
+        canvas.drawLine(center, Offset(dotX, dotY), linePaint);
-          center,
-          Offset(dotX, dotY),
-          linePaint,
-        );
 
         // Draw contact dot (size varies with zoom)
         final dotSize = (6.0 * (1.0 + zoomLevel * 0.3)).clamp(4.0, 12.0);
@@ -341,7 +353,10 @@ class _LargeCompassPainter extends CustomPainter {
 
           textPainter.paint(
             canvas,
-            Offset(labelX - textPainter.width / 2, labelY - textPainter.height / 2),
+            Offset(
+              labelX - textPainter.width / 2,
+              labelY - textPainter.height / 2,
+            ),
           );
         }
       }
@@ -419,11 +434,7 @@ class _LargeCompassPainter extends CustomPainter {
           ..color = markerColor.withValues(alpha: 0.3)
           ..style = PaintingStyle.stroke
           ..strokeWidth = 2;
-        canvas.drawLine(
+        canvas.drawLine(center, Offset(dotX, dotY), linePaint);
-          center,
-          Offset(dotX, dotY),
-          linePaint,
-        );
 
         // Draw SAR marker dot (slightly larger than contacts)
         final dotSize = (8.0 * (1.0 + zoomLevel * 0.3)).clamp(6.0, 14.0);
@@ -472,7 +483,10 @@ class _LargeCompassPainter extends CustomPainter {
 
           textPainter.paint(
             canvas,
-            Offset(labelX - textPainter.width / 2, labelY - textPainter.height / 2),
+            Offset(
+              labelX - textPainter.width / 2,
+              labelY - textPainter.height / 2,
+            ),
           );
         }
       }
@@ -492,27 +506,31 @@ class _LargeCompassPainter extends CustomPainter {
     canvas.drawPath(path, indicatorPaint);
   }
 
-  double _calculateBearing(
+  double _calculateBearing(double lat1, double lon1, double lat2, double lon2) {
-      double lat1, double lon1, double lat2, double lon2) {
     final dLon = (lon2 - lon1) * pi / 180;
     final lat1Rad = lat1 * pi / 180;
     final lat2Rad = lat2 * pi / 180;
 
     final y = sin(dLon) * cos(lat2Rad);
-    final x = cos(lat1Rad) * sin(lat2Rad) -
+    final x =
-        sin(lat1Rad) * cos(lat2Rad) * cos(dLon);
+        cos(lat1Rad) * sin(lat2Rad) - sin(lat1Rad) * cos(lat2Rad) * cos(dLon);
 
     final bearing = atan2(y, x) * 180 / pi;
     return (bearing + 360) % 360;
   }
 
   double _calculateDistance(
-      double lat1, double lon1, double lat2, double lon2) {
+    double lat1,
+    double lon1,
+    double lat2,
+    double lon2,
+  ) {
     const R = 6371000; // Earth's radius in meters
     final dLat = (lat2 - lat1) * pi / 180;
     final dLon = (lon2 - lon1) * pi / 180;
 
-    final a = sin(dLat / 2) * sin(dLat / 2) +
+    final a =
+        sin(dLat / 2) * sin(dLat / 2) +
         cos(lat1 * pi / 180) *
             cos(lat2 * pi / 180) *
             sin(dLon / 2) *
@@ -572,7 +590,8 @@ class _LocationFormatToggleState extends State<_LocationFormatToggle> {
     final String displayText;
 
     if (_showDMS) {
-      displayText = '${_formatDMS(position.latitude, true)} ${_formatDMS(position.longitude, false)}';
+      displayText =
+          '${_formatDMS(position.latitude, true)} ${_formatDMS(position.longitude, false)}';
     } else {
       displayText = l10n.latLonFormat(
         position.latitude.toStringAsFixed(5),
@@ -598,9 +617,9 @@ class _LocationFormatToggleState extends State<_LocationFormatToggle> {
             displayText,
             textAlign: TextAlign.center,
             style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                  fontWeight: FontWeight.w600,
+              fontWeight: FontWeight.w600,
-                  fontFamily: 'monospace',
+              fontFamily: 'monospace',
-                ),
+            ),
           ),
         ),
       ),

lib/widgets/map/compass/compass_math.dart

@@ -0,0 +1,22 @@
+import 'dart:math';
+
+/// Rotate the compass rose opposite the device heading so the current heading
+/// stays under the fixed indicator at the top of the dial.
+double compassRoseRotationRadians(double headingDegrees) {
+  final normalizedHeading = headingDegrees % 360;
+  return _normalizeRadians(-normalizedHeading * pi / 180);
+}
+
+/// Convert a compass marker bearing into an on-screen angle for the dial.
+double compassDialAngleRadians({
+  required double markerDegrees,
+  required double headingDegrees,
+}) {
+  return _normalizeRadians(
+    markerDegrees * pi / 180 -
+        pi / 2 +
+        compassRoseRotationRadians(headingDegrees),
+  );
+}
+
+double _normalizeRadians(double angle) => atan2(sin(angle), cos(angle));

lib/widgets/map/compass_widget.dart

@@ -1,5 +1,6 @@
 import 'dart:math';
 import 'package:flutter/material.dart';
+import 'compass/compass_math.dart';
 
 class CompassWidget extends StatelessWidget {
   final double heading;
@@ -21,9 +22,9 @@ class CompassWidget extends StatelessWidget {
         child: Stack(
           alignment: Alignment.center,
           children: [
-            // Compass rose background - rotates to show true north at top
+            // Rotate the rose opposite the heading under the fixed needle.
             Transform.rotate(
-              angle: heading * pi / 180,
+              angle: compassRoseRotationRadians(heading),
               child: CustomPaint(
                 size: const Size(40, 40),
                 painter: _CompassRosePainter(),
@@ -76,9 +77,7 @@ class _CompassRosePainter extends CustomPainter {
     canvas.drawCircle(center, radius, paint);
 
     // Draw cardinal direction markers
-    final textPainter = TextPainter(
+    final textPainter = TextPainter(textDirection: TextDirection.ltr);
-      textDirection: TextDirection.ltr,
-    );
 
     final directions = ['N', 'E', 'S', 'W'];
     for (int i = 0; i < 4; i++) {

linux/flutter/generated_plugin_registrant.cc

@@ -9,6 +9,7 @@
 #include <audioplayers_linux/audioplayers_linux_plugin.h>
 #include <file_selector_linux/file_selector_plugin.h>
 #include <flutter_avif_linux/flutter_avif_linux_plugin.h>
+#include <flutter_libserialport/flutter_libserialport_plugin.h>
 #include <record_linux/record_linux_plugin.h>
 #include <url_launcher_linux/url_launcher_plugin.h>
 
@@ -22,6 +23,9 @@ void fl_register_plugins(FlPluginRegistry* registry) {
   g_autoptr(FlPluginRegistrar) flutter_avif_linux_registrar =
       fl_plugin_registry_get_registrar_for_plugin(registry, "FlutterAvifLinuxPlugin");
   flutter_avif_linux_plugin_register_with_registrar(flutter_avif_linux_registrar);
+  g_autoptr(FlPluginRegistrar) flutter_libserialport_registrar =
+      fl_plugin_registry_get_registrar_for_plugin(registry, "FlutterLibserialportPlugin");
+  flutter_libserialport_plugin_register_with_registrar(flutter_libserialport_registrar);
   g_autoptr(FlPluginRegistrar) record_linux_registrar =
       fl_plugin_registry_get_registrar_for_plugin(registry, "RecordLinuxPlugin");
   record_linux_plugin_register_with_registrar(record_linux_registrar);

linux/flutter/generated_plugins.cmake

@@ -6,6 +6,7 @@ list(APPEND FLUTTER_PLUGIN_LIST
   audioplayers_linux
   file_selector_linux
   flutter_avif_linux
+  flutter_libserialport
   record_linux
   url_launcher_linux
 )

macos/Flutter/GeneratedPluginRegistrant.swift

@@ -11,6 +11,7 @@ import file_picker
 import file_selector_macos
 import flutter_avif_macos
 import flutter_blue_plus_darwin
+import flutter_libserialport
 import flutter_local_notifications
 import geolocator_apple
 import nsd_macos
@@ -30,6 +31,7 @@ func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   FileSelectorPlugin.register(with: registry.registrar(forPlugin: "FileSelectorPlugin"))
   FlutterAvifPlugin.register(with: registry.registrar(forPlugin: "FlutterAvifPlugin"))
   FlutterBluePlusPlugin.register(with: registry.registrar(forPlugin: "FlutterBluePlusPlugin"))
+  FlutterLibserialportPlugin.register(with: registry.registrar(forPlugin: "FlutterLibserialportPlugin"))
   FlutterLocalNotificationsPlugin.register(with: registry.registrar(forPlugin: "FlutterLocalNotificationsPlugin"))
   GeolocatorPlugin.register(with: registry.registrar(forPlugin: "GeolocatorPlugin"))
   NsdMacosPlugin.register(with: registry.registrar(forPlugin: "NsdMacosPlugin"))

macos/Podfile

@@ -1,4 +1,4 @@
-platform :osx, '10.15'
+platform :osx, '26.0'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'
@@ -38,6 +38,9 @@ end
 post_install do |installer|
   installer.pods_project.targets.each do |target|
     flutter_additional_macos_build_settings(target)
+    target.build_configurations.each do |config|
+      config.build_settings['MACOSX_DEPLOYMENT_TARGET'] = '26.0'
+    end
     # codec2_flutter uses ARM-specific register asm("sp") in debug_alloc.h that
     # does not compile on x86_64 macOS. Voice messages are iOS-only, so exclude
     # all C source files from the macOS codec2_flutter build entirely.

macos/Podfile.lock

@@ -15,12 +15,16 @@ PODS:
   - flutter_blue_plus_darwin (0.0.2):
     - Flutter
     - FlutterMacOS
+  - flutter_libserialport (0.0.1):
+    - FlutterMacOS
+    - libserialport
   - flutter_local_notifications (0.0.1):
     - FlutterMacOS
   - FlutterMacOS (1.0.0)
   - geolocator_apple (1.2.0):
     - Flutter
     - FlutterMacOS
+  - libserialport (0.1.1)
   - nsd_macos (0.0.1):
     - FlutterMacOS
   - package_info_plus (0.0.1):
@@ -40,6 +44,8 @@ PODS:
     - FlutterMacOS
   - url_launcher_macos (0.0.1):
     - FlutterMacOS
+  - wakelock_plus (0.0.1):
+    - FlutterMacOS
 
 DEPENDENCIES:
   - audioplayers_darwin (from `Flutter/ephemeral/.symlinks/plugins/audioplayers_darwin/darwin`)
@@ -49,6 +55,7 @@ DEPENDENCIES:
   - file_selector_macos (from `Flutter/ephemeral/.symlinks/plugins/file_selector_macos/macos`)
   - flutter_avif_macos (from `Flutter/ephemeral/.symlinks/plugins/flutter_avif_macos/macos`)
   - flutter_blue_plus_darwin (from `Flutter/ephemeral/.symlinks/plugins/flutter_blue_plus_darwin/darwin`)
+  - flutter_libserialport (from `Flutter/ephemeral/.symlinks/plugins/flutter_libserialport/macos`)
   - flutter_local_notifications (from `Flutter/ephemeral/.symlinks/plugins/flutter_local_notifications/macos`)
   - FlutterMacOS (from `Flutter/ephemeral`)
   - geolocator_apple (from `Flutter/ephemeral/.symlinks/plugins/geolocator_apple/darwin`)
@@ -60,6 +67,11 @@ DEPENDENCIES:
   - shared_preferences_foundation (from `Flutter/ephemeral/.symlinks/plugins/shared_preferences_foundation/darwin`)
   - sqflite_darwin (from `Flutter/ephemeral/.symlinks/plugins/sqflite_darwin/darwin`)
   - url_launcher_macos (from `Flutter/ephemeral/.symlinks/plugins/url_launcher_macos/macos`)
+  - wakelock_plus (from `Flutter/ephemeral/.symlinks/plugins/wakelock_plus/macos`)
+
+SPEC REPOS:
+  trunk:
+    - libserialport
 
 EXTERNAL SOURCES:
   audioplayers_darwin:
@@ -76,6 +88,8 @@ EXTERNAL SOURCES:
     :path: Flutter/ephemeral/.symlinks/plugins/flutter_avif_macos/macos
   flutter_blue_plus_darwin:
     :path: Flutter/ephemeral/.symlinks/plugins/flutter_blue_plus_darwin/darwin
+  flutter_libserialport:
+    :path: Flutter/ephemeral/.symlinks/plugins/flutter_libserialport/macos
   flutter_local_notifications:
     :path: Flutter/ephemeral/.symlinks/plugins/flutter_local_notifications/macos
   FlutterMacOS:
@@ -98,6 +112,8 @@ EXTERNAL SOURCES:
     :path: Flutter/ephemeral/.symlinks/plugins/sqflite_darwin/darwin
   url_launcher_macos:
     :path: Flutter/ephemeral/.symlinks/plugins/url_launcher_macos/macos
+  wakelock_plus:
+    :path: Flutter/ephemeral/.symlinks/plugins/wakelock_plus/macos
 
 SPEC CHECKSUMS:
   audioplayers_darwin: 835ced6edd4c9fc8ebb0a7cc9e294a91d99917d5
@@ -107,9 +123,11 @@ SPEC CHECKSUMS:
   file_selector_macos: 9e9e068e90ebee155097d00e89ae91edb2374db7
   flutter_avif_macos: 9ed61d67adfbd6964eccb59971020fb55c31fc11
   flutter_blue_plus_darwin: 20a08bfeaa0f7804d524858d3d8744bcc1b6dbc3
+  flutter_libserialport: 2c523cb8d8203fc6d1b0da88190da31ac970eb93
   flutter_local_notifications: 1fc7ffb10a83d6a2eeeeddb152d43f1944b0aad0
   FlutterMacOS: d0db08ddef1a9af05a5ec4b724367152bb0500b1
   geolocator_apple: ab36aa0e8b7d7a2d7639b3b4e48308394e8cef5e
+  libserialport: 1cb25e66ef3c92a8e59c2ea3820302c3fa2268cd
   nsd_macos: a472240e770b92f6c6df1022403aa29c90d012e3
   package_info_plus: f0052d280d17aa382b932f399edf32507174e870
   path_provider_foundation: bb55f6dbba17d0dccd6737fe6f7f34fbd0376880
@@ -118,7 +136,8 @@ SPEC CHECKSUMS:
   shared_preferences_foundation: 7036424c3d8ec98dfe75ff1667cb0cd531ec82bb
   sqflite_darwin: 20b2a3a3b70e43edae938624ce550a3cbf66a3d0
   url_launcher_macos: f87a979182d112f911de6820aefddaf56ee9fbfd
+  wakelock_plus: 917609be14d812ddd9e9528876538b2263aaa03b
 
-PODFILE CHECKSUM: e3de8f2486e300492cc80a2fe0576e9d269ba22b
+PODFILE CHECKSUM: 467066e8d30d1105257e0877b8cdd20642e7b3db
 
 COCOAPODS: 1.16.2

macos/Runner.xcodeproj/project.pbxproj

@@ -557,7 +557,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				MACOSX_DEPLOYMENT_TARGET = 10.15;
+				MACOSX_DEPLOYMENT_TARGET = 26.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
 				SWIFT_COMPILATION_MODE = wholemodule;
@@ -639,7 +639,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				MACOSX_DEPLOYMENT_TARGET = 10.15;
+				MACOSX_DEPLOYMENT_TARGET = 26.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = macosx;
@@ -689,7 +689,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				MACOSX_DEPLOYMENT_TARGET = 10.15;
+				MACOSX_DEPLOYMENT_TARGET = 26.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
 				SWIFT_COMPILATION_MODE = wholemodule;

macos/Runner/DebugProfile.entitlements

@@ -2,11 +2,7 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
-	<key>com.apple.security.app-sandbox</key>
-	<true/>
 	<key>com.apple.security.cs.allow-jit</key>
 	<true/>
-	<key>com.apple.security.network.server</key>
-	<true/>
 </dict>
 </plist>

macos/Runner/Info.plist

@@ -24,10 +24,16 @@
 	<false/>
 	<key>LSMinimumSystemVersion</key>
 	<string>$(MACOSX_DEPLOYMENT_TARGET)</string>
+	<key>NSBluetoothAlwaysUsageDescription</key>
+	<string>MeshCore SAR needs Bluetooth to discover and communicate with MeshCore devices during SAR operations</string>
+	<key>NSBluetoothPeripheralUsageDescription</key>
+	<string>MeshCore SAR needs Bluetooth to discover and communicate with MeshCore devices during SAR operations</string>
 	<key>NSHumanReadableCopyright</key>
 	<string>$(PRODUCT_COPYRIGHT)</string>
 	<key>NSMainNibFile</key>
 	<string>MainMenu</string>
+	<key>NSLocationUsageDescription</key>
+	<string>MeshCore SAR needs your location to track your team, share your position over the mesh network, and show your location on the map during SAR operations</string>
 	<key>NSMicrophoneUsageDescription</key>
 	<string>MeshCore SAR needs microphone access to send voice messages over the mesh radio network during SAR operations</string>
 	<key>NSPrincipalClass</key>

macos/Runner/Release.entitlements

@@ -2,7 +2,5 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
-	<key>com.apple.security.app-sandbox</key>
-	<true/>
 </dict>
 </plist>

pubspec.lock

@@ -218,6 +218,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "7.0.3"
+  dylib:
+    dependency: transitive
+    description:
+      name: dylib
+      sha256: bf609b3eb6492a3309b3d1dbe8f83a4031de5535dd7686be33487051cc760bb0
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.3"
   exif:
     dependency: transitive
     description:
@@ -479,6 +487,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.14.4"
+  flutter_libserialport:
+    dependency: "direct main"
+    description:
+      name: flutter_libserialport
+      sha256: f24b5fe6f1821d1c1b3bf2be737ca53f6b0ae78657032a790aa00abb810c8759
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.6.0"
   flutter_lints:
     dependency: "direct dev"
     description:
@@ -759,6 +775,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.0.2"
+  libserialport:
+    dependency: transitive
+    description:
+      name: libserialport
+      sha256: "392e1592def65282429832ec66fa25e9e163d3b37716b97691482e2406720727"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.0+1"
   lints:
     dependency: transitive
     description:
@@ -1477,6 +1501,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.1.1"
+  webserial:
+    dependency: "direct main"
+    description:
+      name: webserial
+      sha256: b39c2175190ee1c75e996bf137bfee3e3e8fd06ee0ec24f0d3c10bdf7b323786
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.0"
   win32:
     dependency: transitive
     description:

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 2026.0318.1+34
+version: 2026.0319.1+35
 
 environment:
   sdk: ^3.9.2
@@ -123,6 +123,8 @@ dependencies:
   nsd: ^4.0.3
   usb_serial: ^0.5.2
   web: ^1.1.1
+  flutter_libserialport: ^0.6.0
+  webserial: ^1.2.0
 
 dev_dependencies:
   flutter_test:

test/screens/contacts_tab_test.dart

@@ -1,5 +1,3 @@
-import 'dart:typed_data';
-
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';

test/widgets/compass_math_test.dart

@@ -0,0 +1,36 @@
+import 'dart:math';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:meshcore_sar_app/widgets/map/compass/compass_math.dart';
+
+void main() {
+  group('compass dial math', () {
+    test('rotates the rose opposite the heading', () {
+      expect(compassRoseRotationRadians(0), closeTo(0, 1e-10));
+      expect(compassRoseRotationRadians(90), closeTo(-pi / 2, 1e-10));
+      expect(compassRoseRotationRadians(450), closeTo(-pi / 2, 1e-10));
+    });
+
+    test('places east at the top when heading east', () {
+      expect(
+        compassDialAngleRadians(markerDegrees: 90, headingDegrees: 90),
+        closeTo(-pi / 2, 1e-10),
+      );
+      expect(
+        compassDialAngleRadians(markerDegrees: 270, headingDegrees: 90),
+        closeTo(pi / 2, 1e-10),
+      );
+    });
+
+    test('places west at the top when heading west', () {
+      expect(
+        compassDialAngleRadians(markerDegrees: 270, headingDegrees: 270),
+        closeTo(-pi / 2, 1e-10),
+      );
+      expect(
+        compassDialAngleRadians(markerDegrees: 90, headingDegrees: 270),
+        closeTo(pi / 2, 1e-10),
+      );
+    });
+  });
+}

windows/flutter/generated_plugin_registrant.cc

@@ -10,6 +10,7 @@
 #include <file_selector_windows/file_selector_windows.h>
 #include <flutter_avif_windows/flutter_avif_windows_plugin.h>
 #include <flutter_blue_plus_winrt/flutter_blue_plus_plugin.h>
+#include <flutter_libserialport/flutter_libserialport_plugin.h>
 #include <geolocator_windows/geolocator_windows.h>
 #include <nsd_windows/nsd_windows_plugin_c_api.h>
 #include <permission_handler_windows/permission_handler_windows_plugin.h>
@@ -26,6 +27,8 @@ void RegisterPlugins(flutter::PluginRegistry* registry) {
       registry->GetRegistrarForPlugin("FlutterAvifWindowsPlugin"));
   FlutterBluePlusPluginRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("FlutterBluePlusPlugin"));
+  FlutterLibserialportPluginRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("FlutterLibserialportPlugin"));
   GeolocatorWindowsRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("GeolocatorWindows"));
   NsdWindowsPluginCApiRegisterWithRegistrar(

windows/flutter/generated_plugins.cmake

@@ -7,6 +7,7 @@ list(APPEND FLUTTER_PLUGIN_LIST
   file_selector_windows
   flutter_avif_windows
   flutter_blue_plus_winrt
+  flutter_libserialport
   geolocator_windows
   nsd_windows
   permission_handler_windows