CodePudding user response:

For the open operation times the wrong

PortId=CommPortIdentifier. GetPortIdentifier (portName);
If (portId==null) {
System. The out. Println (" port is null ");
}
COMname=portName;
//open ports, and port name and a timeout (open operation timeout)
Thread.sleep (10);
CommPort CommPort=portId. Open (portName, 10);
//determine whether serial
If (commPort instanceof SerialPort) {
SerialPort=(serialPort commPort);


//set the baud rate of serial port parameters such as
//data bits: 8
//stop bit: 1
//check digit: None
SerialPort. SetSerialPortParams (115200, serialPort. DATABITS_8, serialPort. STOPBITS_1,
SerialPort. PARITY_NONE);
//below is used for communication and the COM input, the output stream,
In=new InputStreamReader (serialPort getInputStream ());
Out=new OutputStreamWriter (serialPort getOutputStream ());