I am using Java Comm API to send some data on Serial Port and Again Checking it back. The Problem is that I am not able to get the correct data back always. Sometime I see a garbage value there.
Here is my Code
Setup SerialPort For Sending Data
public void setUpSerialPort()
{
CommPortIdentifier portId = null;
try
{
portId = CommPortIdentifier.getPortIdentifier("COM7");
} catch (NoSuchPortException ex) {
JOptionPane.showMessageDialog(null, "Sorry no such port exists.Please check your connections");
serialflag=false;
}
try
{
mySerialPort = (SerialPort) portId.open("AutoPilot on COM7",5000);
//configure the port
} catch (PortInUseException ex) {
JOptionPane.showMessageDialog(null, "Sorry port already in use by other device.\nClose all other applications that might be accessing this port");
serialflag=false;
}
//configure the port
try
{
mySerialPort.setSerialPortParams(115200,mySerialPort.DATABITS_8,mySerialPort.STOPBITS_1,mySerialPort.PARITY_NONE);
mySerialPort.setFlowControlMode(mySerialPort.FLOWCONTROL_NONE);
mySerialPort.setInputBufferSize(1);
mySerialPort.setOutputBufferSize(1);
} catch (Exception e){JOptionPane.showMessageDialog(null, "Sorry could not connect due to Windows error. Please retry");serialflag=false;}
System.out.println(mySerialPort.getInputBufferSize());
System.out.println(mySerialPort.getBaudRate()+" "+ mySerialPort.getDataBits()+" "+" "+mySerialPort.getStopBits()+" "+mySerialPort.getParity()+" "+mySerialPort.getFlowControlMode());
try
{
in = new DataInputStream(mySerialPort.getInputStream());
} catch (IOException ex) {
ex.printStackTrace();
}
try
{
mySerialPort.addEventListener(this);
mySerialPort.notifyOnDataAvailable(true);
} catch (TooManyListenersException e) {System.out.println("couldn't add listener");}
}Code where I send Data
byte[] message = new byte [14];
int crc=0;
byte[] mesg;
byte[] arr = new byte [2];
mesg="#".getBytes();
message[0] = mesg[0];
mesg = "UP".getBytes();
message[1] = mesg[0];
message[2] = mesg[1];
arr = shortToByteArray((short)slider1.getValue());
message[4] = arr[0];
message[3] = arr[1];
arr = shortToByteArray((short)slider2.getValue());
message[6] = arr[0];
message[5] = arr[1];
arr = shortToByteArray((short)slider3.getValue());
message[8] = arr[0];
message[7] = arr[1];
mesg = frameId1.getBytes();
message[9] = mesg[0];
message[10] = mesg[1];
for(int i=0;i<11;i++)
crc=crc^message[i];
//mesg =
mesg = "000".getBytes();
message[11] = mesg[0];
message[12] = mesg[1];
message[13] = mesg[2];
//setUpSerialPort();
//System.out.println(mySerialPort.getBaudRate()+" "+ mySerialPort.getDataBits()+" "+" "+mySerialPort.getStopBits()+" "+mySerialPort.getParity()+" "+mySerialPort.getFlowControlMode());
out = new PrintStream(mySerialPort.getOutputStream());
out.write(message);
/*out.write("#".getBytes());
out.write("UP".getBytes());
out.write(message, 3,6);
out.write(frameId1.getBytes());
out.write("000".getBytes*/public static byte[] shortToByteArray(short s)
{
return new byte[] { (byte) ((s & 0xFF00) >> 8), (byte) (s & 0x00FF) };
}I had sending the complete package in one go and sending in bytewise also
This is the code where I setUP to Recieve data. The value of WHichPort in now COM4 and whichSpeed is 115200
public PhysCompSerialDemo (String whichPort, int whichSpeed) throws PortInUseException {
CommPortIdentifier portId = null;
try {
portId = CommPortIdentifier.getPortIdentifier(whichPort);
} catch (NoSuchPortException ex) {
ex.printStackTrace();
}
//open the port
mySerialPort = (SerialPort)portId.open("SerialExample " + whichPort, 2000);
//configure the port
try {
mySerialPort.setSerialPortParams(whichSpeed,
mySerialPort.DATABITS_8,
mySerialPort.STOPBITS_1,
mySerialPort.PARITY_NONE);
mySerialPort.setFlowControlMode(mySerialPort.FLOWCONTROL_NONE);
mySerialPort.setInputBufferSize(1);
} catch (Exception e){e.printStackTrace();}
System.out.println(mySerialPort.getBaudRate()+" "+ mySerialPort.getDataBits()+" "+" "+mySerialPort.getStopBits()+" "+mySerialPort.getParity()+" "+mySerialPort.getFlowControlMode());
try {
in = new DataInputStream(mySerialPort.getInputStream());
out = new PrintStream(mySerialPort.getOutputStream());
} catch (IOException ex) {
ex.printStackTrace();
}
try {
mySerialPort.addEventListener(this);
mySerialPort.notifyOnDataAvailable(true);
} catch (TooManyListenersException e) {System.out.println("couldn't add listener");}
}
public void serialEvent(SerialPortEvent event) {
if (event.getEventType()== SerialPortEvent.DATA_AVAILABLE) {
try {
while(((check[0]=(char)(in.read()))!='#')||((check[1]=(char)(in.read()))!='U')||((check[2]=(char)(in.read()))!='P'));
for(int i=0;i<3;i++)
{
read_short[1]=in.readByte();
read_short[0]=in.readByte();
DataInputStream data_stream1 = new DataInputStream(new ByteArrayInputStream(read_short));
short_rec[i]=data_stream1.readShort();
}
for(int i=0;i<3;i++)
System.out.print(short_rec[i]+" ");
for(int i=0;i<5;i++)
System.out.print((char)in.read()+" ");
System.out.println();
} catch (Exception ex) {
ex.printStackTrace();
}
} //it’s a serial port event
}Some time I am getting correct data and some time there is a garbage
Please Explain how to solve this