GNSS szervíz refraktorálás, hibajavítás, PhoneGpsConnection osztály

lib/services/gnss/ble_gnss_connection.dart

@@ -1,6 +1,9 @@
 // lib/services/gnss/ble_gnss_connection.dart
 import 'dart:async';
+import 'dart:io';
+import 'dart:typed_data';
 import 'package:flutter_blue_plus/flutter_blue_plus.dart';
+import 'package:geolocator/geolocator.dart';
 import 'gnss_connection.dart';
 import 'gnss_device_service.dart';
 
@@ -24,6 +27,7 @@ class BleGnssConnection implements GnssConnection {
   BluetoothDevice? _device;
   StreamSubscription? _notifySub;
   String _lineBuffer = '';
+  BluetoothCharacteristic? _rxChar;
 
   final _nmeaController = StreamController<String>.broadcast();
   final _stateController = StreamController<GnssConnectionState>.broadcast();
@@ -46,6 +50,10 @@ class BleGnssConnection implements GnssConnection {
           autoConnect: false,
           license: License.free);
 
+      if (Platform.isAndroid) {
+        await _device!.requestMtu(512);
+      }
+
       // Kapcsolat megszakadás figyelése
       _device!.connectionState.listen((state) {
         if (state == BluetoothConnectionState.disconnected) {
@@ -68,6 +76,10 @@ class BleGnssConnection implements GnssConnection {
         orElse: () => throw Exception('TX char nem található: $txCharUuid'),
       );
 
+      _rxChar = gnssService.characteristics.firstWhere((c) =>
+          c.characteristicUuid.str.toLowerCase() ==
+          _nusRxCharUuid.toLowerCase());
+
       // Notify engedélyezése
       await txChar.setNotifyValue(true);
 
@@ -109,4 +121,14 @@ class BleGnssConnection implements GnssConnection {
     _nmeaController.close();
     _stateController.close();
   }
+
+  @override
+  void sendData(Uint8List data) {
+    if (_rxChar == null) return;
+
+    _rxChar!.write(data, withoutResponse: true);
+  }
+
+  @override
+  Stream<Position> get positionStream => const Stream.empty();
 }