Cfrtjryk

I want to do two way communication with an embedded controller using Java over the COM port. When I send some string to the controller my controller sends me the return response:

example string   01 04 01 00 00 0C F1 F3

public class SerialClass implements SerialPortEventListener 

{



    public SerialPort serialPort;

    /** The port we're normally going to use. */

    private static final String PORT_NAMES = 

    {

        "/dev/tty.usbserial-A9007UX1", // Mac OS X

        "/dev/ttyUSB0", // Linux

        "COM9", // Windows

    };



    public static BufferedReader input;

    public static OutputStream output;

    /** Milliseconds to block while waiting for port open */

    public static final int TIME_OUT = 200;

    /** Default bits per second for COM port. */

    public static final int DATA_RATE = 9600;



    public void initialize() 

    {

        CommPortIdentifier portId = null;

        Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();



        //First, Find an instance of serial port as set in PORT_NAMES.

        while (portEnum.hasMoreElements()) 

        {

            CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement();

            for (String portName : PORT_NAMES) 

            {

                if (currPortId.getName().equals(portName)) 

                {

                    portId = currPortId;

                    break;

                }

            }

        }

        if (portId == null) 

        {

            System.out.println("Could not find COM port.");

            return;

        }



        try 

        {

            // open serial port, and use class name for the appName.

            serialPort = (SerialPort) portId.open(this.getClass().getName(),

            TIME_OUT);



            // set port parameters

            serialPort.setSerialPortParams(DATA_RATE,

            SerialPort.DATABITS_8,

            SerialPort.STOPBITS_1,

            SerialPort.PARITY_NONE);



            // open the streams

            input = new BufferedReader(new InputStreamReader(serialPort.getInputStream()));

            output = serialPort.getOutputStream();

            char ch = 1;

            output.write(ch);



            // add event listeners

            serialPort.addEventListener(this);

            serialPort.notifyOnDataAvailable(true);

        }

        catch (Exception e) 

        {

            System.err.println(e.toString());

        }

    }



    public synchronized void close() 

    {

        if (serialPort != null) 

        {

            serialPort.removeEventListener();

            serialPort.close();

        }

    }



    @Override

    public synchronized void serialEvent(SerialPortEvent oEvent) 

    {

        if (oEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) 

        {

            try 

            {

                String inputLine=input.readLine();

                System.out.println("aa"+inputLine);

            } 

            catch (Exception e) 

            {

                System.err.println(e.toString());

            }

        }



    }



    public static synchronized void writeData(String data) 

    {

        System.out.println("Sent: " + data);

        try 

        {

            output.write(data.getBytes());

        } 

        catch (Exception e) 

        {

            System.out.println("could not write to port");

        }

    }



    public static void main(String args) throws Exception {

    SerialClass main = new SerialClass();

    main.initialize();

    Thread t=new Thread() 

    {

        public void run() 

        {

            //the following line will keep this app alive for 1000 seconds,

            //waiting for events to occur and responding to them (printing incoming messages to console).

            try 

            {

                Thread.sleep(1500);

                writeData("01 04 01 00 00 0C F1 F3");



                //serialEvent

            } 

            catch (InterruptedException ie) 

            {



            }

        }

    };

    t.start();

    System.out.println("Started");

    }

}