flutter_bluetooth_serial

Flutter basic implementation for Classical Bluetooth (only RFCOMM for now).

Features

The first goal of this project, started by @edufolly was making an interface for Serial Port Protocol (HC-05 Adapter). Now the plugin features:

• Adapter status monitoring,

• Turning adapter on and off,

• Opening settings,

• Discovering devices (and requesting discoverability),

• Listing bonded devices and pairing new ones,

• Connecting to multiple devices at the same time,

• Sending and receiving data (multiple connections).

The plugin (for now) uses Serial Port profile for moving data over RFCOMM, so make sure there is running Service Discovery Protocol that points to SP/RFCOMM channel of the device. There could be max up to 7 Bluetooth connections.

For now there is only Android support.

Funding

Your contribution will help drive the development of quality tools for the Flutter and Dart developer community. Any amount will be appreciated. Thank you for your continued support!

PIX

Sua contribuição ajudará a impulsionar o desenvolvimento de ferramentas de qualidade para a comunidade de desenvolvedores Flutter e Dart. Qualquer quantia será apreciada. Obrigado pelo seu apoio contínuo!

Getting Started

Depending

# Add dependency to `pubspec.yaml` of your project.
dependencies:
  # ...
  flutter_bluetooth_serial: ^1.1.0

Installing

flutter pub get

Importing

import 'package:flutter_bluetooth_serial/flutter_bluetooth_serial.dart';

Usage

You should look to the Dart code of the library (mostly documented functions) or to the examples code.

// Some simplest connection :F
try {
    BluetoothConnection connection = await BluetoothConnection.toAddress(address);
    print('Connected to the device');

    connection.input.listen((Uint8List data) {
        print('Data incoming: ${ascii.decode(data)}');
        connection.output.add(data); // Sending data

        if (ascii.decode(data).contains('!')) {
            connection.finish(); // Closing connection
            print('Disconnecting by local host');
        }
    }).onDone(() {
        print('Disconnected by remote request');
    });
}
catch (exception) {
    print('Cannot connect, exception occured');
}

// Send message to connected device
  Future<void> sendMessage(BluetoothConnection connection) async {
    try {
      if (!connection.isConnected) {
        print("Device isn't connected");
        return;
      }
      String message = "hello!";
      // Encode the message to a byte list
      Uint8List encodedMessage = ascii.encode(message);
      // Send the message
      connection.output.add(encodedMessage);
    } catch (e) {
      print("Exception while sending message: $e");
    }
  }

// Receive message from connected device
  Future<void> listenForMessages(BluetoothConnection connection) async {
    // Subscribe to data updates
    StreamSubscription? subscription = connection.input?.listen((data) {
      // Decode the message
      String message = ascii.decode(data);
      print("Received new message: $message");
    }, onDone: () {
      // Cleanup code goes here for when connection is closed
      print("Connection closed");
    });
  }

Note: Work is underway to make the communication easier than operations on byte streams. See #41 for discussion about the topic.

Permissions

See this page on Android Bluetooth permissions and request them according to your needs.

Examples

Check out example application with connections with both Arduino HC-05 and Raspberry Pi (RFCOMM) Bluetooth interfaces.

Main screen and options	Discovery and connecting	Simple chat with server	Background connection

Important Notes

• This package DOES NOT yet support bluetooth server sockets. In classical bluetooth connections, one of the devices must obtain a bluetooth server socket so that clients can connect. If your goal to achieve Flutter to Flutter device connection, you will not be able to achieve such using only this library.
• Android does not require developers to pair/bond devices before attempting to connect them. If devices are not yet bonded, during connection the user will be prompted to accept a pairing request.

To-do list

• Add some utils to easier manage BluetoothConnection (see discussion #41),
• Allow connection method/protocol/UUID specification,
• Listening/server mode,
• Recognizing and displaying BluetoothClass of device,
• Maybe integration with flutter_blue one day ;)

You might also want to check milestones.

Credits

• Eduardo Folly
• Martin Mauch
• Patryk Ludwikowski

After version 0.3.0 we have a lot of collaborators. If you would like to be credited, please send me an email.

Thanks for all the support!