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NeuronRobotics / nrjavaserial

A Java Serial Port system. This is a fork of the RXTX project that uses in jar loading of the native code.
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After altering the baud rate, serial communication no longer works. #234

Open ramen2k10 opened 1 year ago

ramen2k10 commented 1 year ago

I'm attempting to contact with a chip card device using serial communication, which is linked to a reader via a serial port. The communication works fine when I use the initial baud rate 9600, but when I change the initial baud rate (9600) of my serial port communication to a higher baud rate value (e.g. - 115200), the device closes the connection, despite the fact that the same device works fine with a higher baud rate using the javax.comm library. Please see the code snippet attached.

public void setBaudRate(int rate) throws UnsupportedCommOperationException {
    if (null != serialPort) {
        if (serialPort.getBaudRate() != rate) {
            boolean rts = serialPort.isRTS();
            boolean dtr = serialPort.isDTR();
            serialPort = nrSerialPort.getSerialPortInstance();// Extracting the serialPort instance
            serialPort.setSerialPortParams(rate, serialPort.getDataBits(), serialPort.getStopBits(), serialPort.getParity());
            serialPort.setDTR(dtr);
        serialPort.setRTS(rts);
        }
    }
}

Is the baud rate changing supported by the nrjavaserial library?

fkamming commented 9 months ago

I'm attempting to contact with a chip card device using serial communication, which is linked to a reader via a serial port. The communication works fine when I use the initial baud rate 9600, but when I change the initial baud rate (9600) of my serial port communication to a higher baud rate value (e.g. - 115200), the device closes the connection, despite the fact that the same device works fine with a higher baud rate using the javax.comm library. Please see the code snippet attached.

public void setBaudRate(int rate) throws UnsupportedCommOperationException {
  if (null != serialPort) {
      if (serialPort.getBaudRate() != rate) {
          boolean rts = serialPort.isRTS();
          boolean dtr = serialPort.isDTR();
          serialPort = nrSerialPort.getSerialPortInstance();// Extracting the serialPort instance
          serialPort.setSerialPortParams(rate, serialPort.getDataBits(), serialPort.getStopBits(), serialPort.getParity());
          serialPort.setDTR(dtr);
      serialPort.setRTS(rts);
      }
  }
}

Is the baud rate changing supported by the nrjavaserial library?

Changing baud rate works fine in our code. I suspect what is missing in your code is disconnecting and reconnecting. Before you set the new baud rate call serialPort.disconnect(). And afterwards call serialPort.connect().