GNSS eszközhöz való kapcsolódás és bluetooth kommunikáció refraktorálása külön osztályokba

2026-05-11 09:34:41 +02:00
parent 7192fa5322
commit f1a3753f36
6 changed files with 343 additions and 5 deletions
@@ -0,0 +1,111 @@
+// lib/services/gnss/ble_gnss_connection.dart
+import 'dart:async';
+import 'package:flutter_blue_plus/flutter_blue_plus.dart';
+import 'gnss_connection.dart';
+
+// Nordic UART Service — a legelterjedtebb BLE UART profil
+const _nusServiceUuid = '6e400001-b5b3-f393-e0a9-e50e24dcca9e';
+const _nusTxCharUuid = '6e400003-b5b3-f393-e0a9-e50e24dcca9e'; // notify
+const _nusRxCharUuid = '6e400002-b5b3-f393-e0a9-e50e24dcca9e'; // write
+
+class BleGnssConnection implements GnssConnection {
+  @override
+  GnssConnectionType get type => GnssConnectionType.ble;
+
+  final String serviceUuid;
+  final String txCharUuid; // notify (eszköz → telefon)
+
+  BleGnssConnection({
+    this.serviceUuid = _nusServiceUuid,
+    this.txCharUuid = _nusTxCharUuid,
+  });
+
+  BluetoothDevice? _device;
+  StreamSubscription? _notifySub;
+  String _lineBuffer = '';
+
+  final _nmeaController = StreamController<String>.broadcast();
+  final _stateController = StreamController<GnssConnectionState>.broadcast();
+
+  @override
+  Stream<String> get nmeaLines => _nmeaController.stream;
+
+  @override
+  Stream<GnssConnectionState> get connectionState => _stateController.stream;
+
+  @override
+  Future<void> connect(String address) async {
+    _stateController.add(GnssConnectionState.connecting);
+
+    try {
+      _device = BluetoothDevice.fromId(address);
+
+      await _device!.connect(
+          timeout: const Duration(seconds: 10),
+          autoConnect: false,
+          license: License.free);
+
+      // Kapcsolat megszakadás figyelése
+      _device!.connectionState.listen((state) {
+        if (state == BluetoothConnectionState.disconnected) {
+          _stateController.add(GnssConnectionState.disconnected);
+        }
+      });
+
+      // Service discovery
+      final services = await _device!.discoverServices();
+      final gnssService = services.firstWhere(
+        (s) => s.serviceUuid.str.toLowerCase() == serviceUuid.toLowerCase(),
+        orElse: () =>
+            throw Exception('GNSS service nem található: $serviceUuid'),
+      );
+
+      // TX karakterisztika (notify) — eszköztől jönnek az NMEA sorok
+      final txChar = gnssService.characteristics.firstWhere(
+        (c) =>
+            c.characteristicUuid.str.toLowerCase() == txCharUuid.toLowerCase(),
+        orElse: () => throw Exception('TX char nem található: $txCharUuid'),
+      );
+
+      // Notify engedélyezése
+      await txChar.setNotifyValue(true);
+
+      _notifySub = txChar.onValueReceived.listen(_onBleData);
+
+      _stateController.add(GnssConnectionState.connected);
+    } catch (e) {
+      _stateController.add(GnssConnectionState.error);
+      rethrow;
+    }
+  }
+
+  void _onBleData(List<int> bytes) {
+    // BLE csomagok kis méretűek (≤20 byte MTU default),
+    // az NMEA mondatokat össze kell fűzni
+    final chunk = String.fromCharCodes(bytes);
+    _lineBuffer += chunk;
+
+    // Teljes sorok kibocsátása
+    while (_lineBuffer.contains('\n')) {
+      final idx = _lineBuffer.indexOf('\n');
+      final line = _lineBuffer.substring(0, idx).trim();
+      _lineBuffer = _lineBuffer.substring(idx + 1);
+      if (line.isNotEmpty) _nmeaController.add(line);
+    }
+  }
+
+  @override
+  Future<void> disconnect() async {
+    await _notifySub?.cancel();
+    await _device?.disconnect();
+    _stateController.add(GnssConnectionState.disconnected);
+  }
+
+  @override
+  void dispose() {
+    _notifySub?.cancel();
+    _device?.disconnect();
+    _nmeaController.close();
+    _stateController.close();
+  }
+}