read method

@override Future<Uint8List> read(int bytes, { Duration? timeout, })

Read data from the serial port.

The operation attempts to read N bytes of data.

Implementation

@override
Future<Uint8List> read(int bytes, {Duration? timeout}) async {
  if (_usbPort != null) {
    List<int> inData = [];
    final completer = Completer<Uint8List>();

    StreamSubscription<List<int>> subscription;
    subscription = _usbPort!.inputStream!.listen((data) {
      inData.addAll(data);
      if (inData.length >= bytes) {
        completer.complete(Uint8List.fromList(inData));
      }
    }, onError: (error) {
      completer.completeError(error);
    }, cancelOnError: true);
    var rxData = await completer.future
        .timeout(timeout ?? const Duration(seconds: 60), onTimeout: () {
      subscription.cancel();
      return Uint8List.fromList(inData);
    });
    try {
      subscription.cancel();
    } catch (_) {}
    return rxData;
  }
  return Uint8List(0);
}