USB Serial port not listening on connect

[manishbuttan]

No description provided.

[manishbuttan]

Hi, when I open the port in flutter to my USB serial port, it opens fine. But the port won't listen for incoming messages. If I close the port in the app and open it from Tera Term and close it, then open it again in the app, the communcation works fine and the incoming messages are working.

What is the proper way of opening the port and starting communication with the serial port without opening it externally?

Platform : Windows. Flutter.

if (!port.openReadWrite()) {
print("Port not opened: ${SerialPort.lastError}");
}

try {
serialPortReader = SerialPortReader(port);
serialPortReader.stream.listen((data) {
String message = String.fromCharCodes(data);
_processUSBData(message);
});
} catch (e) {
print(SerialPort.lastError);
}

[BluesCool]

Hello,Did you solve this problem, I also encountered.

[micheljung]

You weren't setting up the port correctly, see https://stackoverflow.com/questions/77384956/read-serial-port-in-flutter-dart/78360666#78360666

From the documentation:

For each setting in a port configuration, a special value of -1 can be used, which will cause that setting to be left alone when the configuration is applied by SerialPort.config setter.

When a new configuration is created, all of its settings are initially set to the special -1 value.

You should always configure all settings before using a port. There are no default settings applied by the library. When you open a port, it may have default settings from the OS or driver, or the settings left over by the last program to use it.