USB Serial Communication Plugin for Flutter

A Flutter plugin to interact with USB devices via serial communication. This plugin provides functionalities for listing USB devices, connecting to them, sending/receiving data, and managing serial port configurations.

Features

List available USB devices.
Connect to a specific USB device using serial communication.
Send and receive data through the serial port.
Listen to incoming serial messages.
Monitor device connection status.
Configure USB connection parameters (baud rate, data bits, stop bits, parity).
Manage control signals like DTR (Data Terminal Ready) and RTS (Request to Send).
Purge hardware buffers for read/write operations.

Installation

Add the following to your pubspec.yaml file:

dependencies:
  usb_serial_communication: ^0.0.3

Then, run:

flutter pub get

Usage

Import the Plugin

import 'package:usb_serial_communication/usb_serial_communication.dart';
import 'package:usb_serial_communication/models/device_info.dart';

Get Available USB Devices

final usbCommunication = UsbSerialCommunication();

Future<void> listDevices() async {
  final devices = await usbCommunication.getAvailableDevices();
  devices.forEach((device) {
    print('Device Name: ${device.deviceName}');
  });
}

Connect to a USB Device

final device = devices.first; // Select a device from the list
final baudRate = 9600; // Set the desired baud rate

final success = await usbCommunication.connect(device, baudRate);
if (success) {
  print('Connected to ${device.deviceName}');
} else {
  print('Failed to connect to ${device.deviceName}');
}

Send Data

final data = Uint8List.fromList([0x01, 0x02, 0x03]); // Example data
final success = await usbCommunication.write(data);
if (success) {
  print('Data sent successfully.');
} else {
  print('Failed to send data.');
}

Listen to Serial Messages

final listener = usbCommunication.getSerialMessageListener();

listener.receiveBroadcastStream().listen((message) {
  print('Received message: $message');
});

Disconnect from a Device

await usbCommunication.disconnect();
print('Disconnected from the device.');

Additional Features

Set USB Parameters:

await usbCommunication.setParameters(baudRate, dataBits, stopBits, parity);

Set Control Signals (DTR, RTS):

await usbCommunication.setDTR(true); // Enable DTR
await usbCommunication.setRTS(true); // Enable RTS

Purge Hardware Buffers:

await usbCommunication.purgeHwBuffers(true, true); // Purge both write and read buffers

Example

Below is a complete example showcasing how to use the plugin:

import 'package:flutter/material.dart';
import 'package:usb_serial_communication/usb_serial_communication.dart';
import 'package:usb_serial_communication/models/device_info.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: SerialCommunicationExample(),
    );
  }
}

class SerialCommunicationExample extends StatefulWidget {
  @override
  _SerialCommunicationExampleState createState() =>
      _SerialCommunicationExampleState();
}

class _SerialCommunicationExampleState
    extends State<SerialCommunicationExample> {
  final usbCommunication = UsbSerialCommunication();
  List<DeviceInfo> devices = [];
  String status = "No device connected";

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

  Future<void> listDevices() async {
    final deviceList = await usbCommunication.getAvailableDevices();
    setState(() {
      devices = deviceList;
    });
  }

  Future<void> connectDevice(DeviceInfo device) async {
    final success = await usbCommunication.connect(device, 9600);
    setState(() {
      status = success
          ? "Connected to ${device.deviceName}"
          : "Failed to connect to ${device.deviceName}";
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("USB Serial Communication Example")),
      body: Column(
        children: [
          Text(status),
          Expanded(
            child: ListView.builder(
              itemCount: devices.length,
              itemBuilder: (context, index) {
                final device = devices[index];
                return ListTile(
                  title: Text(device.deviceName),
                  onTap: () => connectDevice(device),
                );
              },
            ),
          ),
        ],
      ),
    );
  }
}

API Reference

Methods

Method	Description
`getAvailableDevices()`	Lists all connected USB devices.
`connect(device, baudRate)`	Connects to a USB device with the specified baud rate.
`disconnect()`	Disconnects from the currently connected device.
`write(data)`	Sends data to the connected USB device.
`getSerialMessageListener()`	Listens to incoming serial messages.
`getDeviceConnectionListener()`	Monitors device connection status.
`setParameters(...)`	Configures USB connection parameters.
`setDTR(value)`	Sets the Data Terminal Ready (DTR) signal.
`setRTS(value)`	Sets the Request to Send (RTS) signal.
`purgeHwBuffers(...)`	Clears hardware buffers for reading/writing.

Supported Platforms

Android
iOS (planned)

License

This plugin is licensed under the MIT License. See the LICENSE file for details.