Flutter Bluetooth Classic

A Flutter plugin for Bluetooth Classic communication supporting Android, iOS, and Windows platforms.

Features

• 🔍 Device Discovery: Scan for and discover nearby Bluetooth Classic devices
• 🔗 Connection Management: Connect and disconnect from Bluetooth devices
• 📡 Data Transmission: Send and receive data over Bluetooth connections
• 📱 Multi-Platform: Supports Android, iOS, and Windows
• 🔄 Real-time Communication: Stream data for real-time applications

Platform Support

Platform	Support
Android	✅
iOS	✅
Windows	✅
macOS	❌
Linux	❌
Web	❌

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  flutter_bluetooth_classic_serial: ^1.0.1

Then run:

flutter pub get

Permissions

Android

Add these permissions to your android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

<!-- For Android 12+ (API 31+) -->
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />

iOS

Add to ios/Runner/Info.plist:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>This app needs Bluetooth access to communicate with devices</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>This app needs Bluetooth access to communicate with devices</string>

Windows

Bluetooth capability is automatically included in the Windows implementation.

Usage

Basic Example

import 'package:flutter_bluetooth_classic_serial/flutter_bluetooth_classic.dart';

class BluetoothService {
  final FlutterBluetoothClassic _bluetooth = FlutterBluetoothClassic.instance;

  // Check if Bluetooth is available
  Future<bool> isBluetoothAvailable() async {
    return await _bluetooth.isAvailable;
  }

  // Get paired devices
  Future<List<BluetoothDevice>> getPairedDevices() async {
    return await _bluetooth.getPairedDevices();
  }

  // Connect to a device
  Future<bool> connectToDevice(BluetoothDevice device) async {
    try {
      BluetoothConnection connection = await BluetoothConnection.toAddress(device.address);
      return connection.isConnected;
    } catch (e) {
      print('Connection failed: $e');
      return false;
    }
  }

  // Send data
  Future<void> sendData(BluetoothConnection connection, String data) async {
    connection.output.add(Uint8List.fromList(data.codeUnits));
    await connection.output.allSent;
  }

  // Listen for incoming data
  void listenForData(BluetoothConnection connection) {
    connection.input!.listen((Uint8List data) {
      String received = String.fromCharCodes(data);
      print('Received: $received');
    });
  }
}

Complete Example

import 'package:flutter/material.dart';
import 'package:flutter_bluetooth_classic_serial/flutter_bluetooth_classic.dart';

class BluetoothScreen extends StatefulWidget {
  @override
  _BluetoothScreenState createState() => _BluetoothScreenState();
}

class _BluetoothScreenState extends State<BluetoothScreen> {
  final FlutterBluetoothClassic _bluetooth = FlutterBluetoothClassic.instance;
  List<BluetoothDevice> _devices = [];
  BluetoothConnection? _connection;
  bool _isConnected = false;

  @override
  void initState() {
    super.initState();
    _loadDevices();
  }

  Future<void> _loadDevices() async {
    try {
      List<BluetoothDevice> devices = await _bluetooth.getPairedDevices();
      setState(() {
        _devices = devices;
      });
    } catch (e) {
      print('Error loading devices: $e');
    }
  }

  Future<void> _connectToDevice(BluetoothDevice device) async {
    try {
      BluetoothConnection connection = await BluetoothConnection.toAddress(device.address);
      setState(() {
        _connection = connection;
        _isConnected = true;
      });

      // Listen for incoming data
      _connection!.input!.listen((Uint8List data) {
        String received = String.fromCharCodes(data);
        print('Received: $received');
      });

    } catch (e) {
      print('Connection failed: $e');
    }
  }

  Future<void> _sendMessage(String message) async {
    if (_connection != null && _isConnected) {
      _connection!.output.add(Uint8List.fromList(message.codeUnits));
      await _connection!.output.allSent;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Bluetooth Classic')),
      body: Column(
        children: [
          Expanded(
            child: ListView.builder(
              itemCount: _devices.length,
              itemBuilder: (context, index) {
                BluetoothDevice device = _devices[index];
                return ListTile(
                  title: Text(device.name ?? 'Unknown Device'),
                  subtitle: Text(device.address),
                  onTap: () => _connectToDevice(device),
                );
              },
            ),
          ),
          if (_isConnected)
            Padding(
              padding: EdgeInsets.all(16),
              child: ElevatedButton(
                onPressed: () => _sendMessage('Hello Bluetooth!'),
                child: Text('Send Message'),
              ),
            ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    _connection?.dispose();
    super.dispose();
  }
}

API Reference

FlutterBluetoothClassic

Main class for Bluetooth operations.

Properties

• isAvailable → Future<bool>: Check if Bluetooth is available
• isEnabled → Future<bool>: Check if Bluetooth is enabled

Methods

• getPairedDevices() → Future<List<BluetoothDevice>>: Get list of paired devices
• startDiscovery() → Future<List<BluetoothDevice>>: Start device discovery

BluetoothConnection

Represents a connection to a Bluetooth device.

Static Methods

• toAddress(String address) → Future<BluetoothConnection>: Connect to device by address

Properties

• isConnected → bool: Connection status
• input → Stream<Uint8List>: Incoming data stream
• output → IOSink: Outgoing data sink

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

If you encounter any issues or have questions, please file an issue on our GitHub repository.