Getting SetCommError when started again after closing the port.

[MANOJKUMAR26]

Hi Team, I am trying to read serial data through USB for flutter windows desktop application. The data gets read the first time properly but when I stop the port and start the reading again, I am getting setCommState error. I am using : serial_port_win32: ^1.3.0

Below is the code I am using to open the port and read the data and close the port.

late SerialPort port; void _getPortsAndClose() { port.close(); showToast( 'Readings stopped successfully', duration: Duration(seconds: 3), position: const ToastPosition(align: Alignment.topRight), backgroundColor: Colors.green ); }

void _getPortsAndOpen(Device selectedDevice) { final List<PortInfo> portInfoLists = SerialPort.getPortsWithFullMessages(); ports = SerialPort.getAvailablePorts(); String datacopy = ''; print(portInfoLists); print(ports); if (ports.isNotEmpty) {

  port = SerialPort(selectedDevice.portName,
      openNow: false,BaudRate:9600, ReadIntervalTimeout: 1, ReadTotalTimeoutConstant: 2);
  port.open();
  
  String incomingData = '';
  String completeData = '';

  // while (port.isOpened) {
  // incomingData = '';
  port.readBytesOnListen(8, (value) {
    print('check vlaue ${utf8.decode(value)}');
  // if (utf8.decode(value) != '+' && utf8.decode(value) != ',') {
  incomingData += utf8.decode(value);
  print('check incoming data ${incomingData.length}');
  if(incomingData.length > 50) {
      String trimmedData = incomingData.substring(35);
      incomingData = trimmedData;
  }
  List<String> parts = incomingData.split(',');
  final regex = RegExp(r'\+\d+(?:\.\d+)?'); // Matches numbers optionally followed by a decimal point
  List<double> extractedValues = [];
  for (var part in parts) {
    final match = regex.matchAsPrefix(part);
    if (match != null) {
      // Extract the captured group (the number) and convert to double
      extractedValues.add(double.parse(match.group(0)!.substring(1))); // Remove leading "+"
    }
  }

  if (extractedValues.length >= 2) {
    completeData = extractedValues[extractedValues.length - 2].toString();
  }
  
  setState(() {data = completeData;});
  }
  );
  }
  
  Can you help me resolve this issue please?
  Below are the attempts I did to fix the issue:
  1) Tries to set stop bits to 0 and 1, didn't help.
  2) Tried giving delay before stopping the port so that if there is any queue it can complete but that also didn't help.