my goal is to send an input from the user using java and send it to the arduino via serial. But arduino isn't behaving like I want it to. I send the data and simply nothing happens! The arduino Rx led blinks when I input something indicating that it's reading, but I don't know why isn't it lighting up LED 13.
Java code:
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import gnu.io.CommPortIdentifier;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import java.util.Enumeration;
import java.util.Scanner;
public class SerialTest implements SerialPortEventListener {
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
"COM7", // Windows
};
/**
* A BufferedReader which will be fed by a InputStreamReader
* converting the bytes into characters
* making the displayed results codepage independent
*/
private DataInputStream input;
/** The output stream to the port */
private DataOutputStream output;
/** Milliseconds to block while waiting for port open */
private static final int TIME_OUT = 2000;
/** Default bits per second for COM port. */
private 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);
input = new DataInputStream (serialPort.getInputStream());
output = new DataOutputStream (serialPort.getOutputStream());
serialPort.addEventListener(this);
serialPort.notifyOnDataAvailable(true);
}catch (Exception e) {
System.err.println(e.toString());
}
while(true)
{
// open the streams
System.out.print("Input something: ");
Scanner sc = new Scanner(System.in);
short x = sc.nextShort();
System.out.println("short is " + x);
//output = new OutputStreamWriter(serialPort.getOutputStream());*/
byte upper = (byte) (x >> 8); //Get the upper 8 bits
byte lower = (byte) (x & 0xFF); //Get the lower 8bits
try{
output.write(upper);
output.write(lower);
}
catch(Exception ex)
{}
// add event listeners
}
}
/**
* This should be called when you stop using the port.
* This will prevent port locking on platforms like Linux.
*/
public synchronized void close() {
if (serialPort != null) {
serialPort.removeEventListener();
serialPort.close();
}
}
/**
* Handle an event on the serial port. Read the data and print it.
*/
public synchronized void serialEvent(SerialPortEvent oEvent) {
if (oEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
try {
int inputLine=input.read();
System.out.println(inputLine);
} catch (Exception e) {
System.err.println(e.toString());
}
}
// Ignore all the other eventTypes, but you should consider the other ones.
}
public static void main(String[] args) throws Exception {
SerialTest main = new SerialTest();
main.initialize();
}
}
Arduino Code:
void setup(){
Serial.begin(9600);
pinMode(13,OUTPUT);
}
void loop(){
if (Serial.available() > 0){
byte upper = Serial.read();
byte lower = Serial.read();
int x = (upper<<8) | lower;
if(x==1200){
digitalWrite(13,HIGH);
}
else{
digitalWrite(13,HIGH);
delay(1000);
digitalWrite(13,LOW);
delay(1000);
}
}
}