Serial communication between Arduino and Java NetBeans

Question

I am new to this serial communication between Arduino and Java NetBeans. I am doing some small project and I need to get data from external EEPROM 24LC256 which is connected to Arduino UNO and pass it to the Java NetBeans platform not the Eclipse. So far I am using RXTX driver to communicate with Arduino in Java and easily get the data from serial monitor of Arduino IDE.

So can anyone help me, on how can I serially communicate with this external EEPROM using Java?

import gnu.io.*;
import java.util.*;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import java.util.Enumeration; 
public class last extends javax.swing.JFrame implements SerialPortEventListener {
 SerialPort serialPort;
 private static final String PORT_NAMES[] = { 
 "COM3", // Windows
 };
 private BufferedReader input; 
 private OutputStream output; /** The output stream to the port */
 private static final int TIME_OUT = 2000; /** Milliseconds to block while waiting for port open */
 private static final int DATA_RATE = 9600; /** Default bits per second for COM port. */
 public void initialize() {
 CommPortIdentifier portId = null;
 Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();
 while (portEnum.hasMoreElements()) { //First, Find an instance of serial port as set in PORT_NAMES.
 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);
 serialPort.setSerialPortParams(DATA_RATE, // set port parameters
 SerialPort.DATABITS_8,
 SerialPort.STOPBITS_1,
 SerialPort.PARITY_NONE);
 input = new BufferedReader(new InputStreamReader(serialPort.getInputStream())); // open the streams
 output = serialPort.getOutputStream();
 serialPort.addEventListener(this); // add event listeners
 serialPort.notifyOnDataAvailable(true);
 } catch (Exception e) {
 System.err.println(e.toString());
 }}
 /**
 * 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 {
 String inputLine=input.readLine();
 System.out.println("the state of the led is "+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 {
 last main = new last();
 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(1000000);} catch (InterruptedException ie) {}
 }
 };
 t.start();
 System.out.println("Started");
 }
}

This is the code in Java NetBeans.

• duck: Perhaps you can attach your code for higher rate of getting a proper answer. Just a wild guess, have you try softserial?
• Stenzin lobsang: here i wrote code

Answer 1

Your EEPROM has I2C interface, so first you shall program Arduino to access it: An I2C EEPROM Class for Arduino

Then implement some kind of communication protocol over serial, to send commands instructing Arduino to read/write from EEPROM. For example, with following commands:

• for writing write:<address>,<count>,<data_as_hex_string>
• for reading read:<address>,<count>
• response for reading: <address>,<count>,<data_as_hex_string>