Data Firmware

Bi direction communication between Arduino and PC using Java jSSC

This example show Bi-direction communication between Arduino Uno and PC using Java + javaFX + jSSC:
Arduino to PC: Arduino Uno analog input, display on JavaFX LineChart
PC to Arduino: Button to control Arduino Uno on-board LED


Before start, you have to Prepare jSSC on your NetBeans project.

Arduino side: AnalogInputToUSB.ino, run on Arduino Uno.

/*
 * AnalogInputUSB
 * Read analog input from analog pin 0
 * and send data to USB
 */

int ledPin = 13;
int analogPin = A0;
int analogValue = 0;

int incomingByte = 0;

void setup() {
 pinMode(ledPin, OUTPUT);
 Serial.begin(9600);
}

void loop() {

 if (Serial.available() > 0) {
 incomingByte = Serial.read();

 if(incomingByte & 0x01){
 digitalWrite(ledPin, HIGH);
 }else{
 digitalWrite(ledPin, LOW);
 }
 }
 
 analogValue = analogRead(analogPin); //Read analog input
 analogValue = map(analogValue, 0, 1023, 0, 255);
 Serial.write(analogValue); //write as byte, to USB

 delay(100);
}a

PC Side, JavaFX_jssc_Uno.java

/*
 * Example of using jSSC library to handle serial port
 * Receive number from Arduino via USB/Serial and display on Label
 */
package javafx_jssc_uno;

import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import jssc.SerialPort;
import static jssc.SerialPort.MASK_RXCHAR;
import jssc.SerialPortEvent;
import jssc.SerialPortException;
import jssc.SerialPortList;

public class JavaFX_jssc_Uno extends Application {
 
 SerialPort arduinoPort = null;
 ObservableList<String> portList;
 
 ToggleButton tbLED13;
 Label labelValue;
 final int NUM_OF_POINT = 50;
 XYChart.Series series;
 
 private void detectPort(){
 
 portList = FXCollections.observableArrayList();
 
 String[] serialPortNames = SerialPortList.getPortNames();
 for(String name: serialPortNames){
 System.out.println(name);
 portList.add(name);
 }
 }
 
 @Override
 public void start(Stage primaryStage) {
 
 labelValue = new Label();
 labelValue.setFont(new Font("Arial", 28));
 
 detectPort();
 final ComboBox comboBoxPorts = new ComboBox(portList);
 comboBoxPorts.valueProperty()
 .addListener(new ChangeListener<String>() {

 @Override
 public void changed(ObservableValue<? extends String> observable, 
 String oldValue, String newValue) {

 System.out.println(newValue);
 disconnectArduino();
 connectArduino(newValue);
 
 tbLED13.setSelected(false);
 }

 });
 
 //Toggle Button to control LED on Arduino 
 tbLED13 = new ToggleButton("Arduino LED 13");
 tbLED13.setOnAction((ActionEvent event) -> {
 updateLED13();
 });
 
 //LineChart
 final NumberAxis xAxis = new NumberAxis();
 final NumberAxis yAxis = new NumberAxis();
 yAxis.setLabel("Voltage");
 
 final LineChart<Number,Number> lineChart = 
 new LineChart<>(xAxis,yAxis);
 lineChart.setTitle("Arduino Uno A0 Analog Input");
 series = new XYChart.Series();
 series.setName("A0 analog input");
 lineChart.getData().add(series);
 lineChart.setAnimated(false);
 
 //pre-load with dummy data
 for(int i=0; i<NUM_OF_POINT; i++){
 series.getData().add(new XYChart.Data(i, 0));
 }
 //
 
 VBox vBox = new VBox();
 vBox.getChildren().addAll(
 comboBoxPorts, 
 tbLED13, 
 labelValue, 
 lineChart);
 
 StackPane root = new StackPane();
 root.getChildren().add(vBox);
 
 Scene scene = new Scene(root, 500, 400);
 
 primaryStage.setTitle(
 "arduino-er.blogspot.com: Java + JavaFX + jSSC demo");
 primaryStage.setScene(scene);
 primaryStage.show();
 }
 
 private void updateLED13(){
 try {
 if(tbLED13.isSelected()){
 if(arduinoPort != null){
 arduinoPort.writeByte((byte)0x01);
 System.out.println("LED 13 ON");
 }else{
 System.out.println("arduinoPort not connected!");
 }
 }else {
 if(arduinoPort != null){
 arduinoPort.writeByte((byte)0x00);
 System.out.println("LED 13 OFF");
 }else{
 System.out.println("arduinoPort not connected!");
 }
 }
 }catch (SerialPortException ex) {
 Logger.getLogger(JavaFX_jssc_Uno.class.getName())
 .log(Level.SEVERE, null, ex);
 }
 }
 
 public void shiftSeriesData(float newValue)
 {
 for(int i=0; i<NUM_OF_POINT-1; i++){
 XYChart.Data<String, Number> ShiftDataUp = 
 (XYChart.Data<String, Number>)series.getData().get(i+1);
 Number shiftValue = ShiftDataUp.getYValue();
 XYChart.Data<String, Number> ShiftDataDn = 
 (XYChart.Data<String, Number>)series.getData().get(i);
 ShiftDataDn.setYValue(shiftValue);
 }
 XYChart.Data<String, Number> lastData = 
 (XYChart.Data<String, Number>)series.getData().get(NUM_OF_POINT-1);
 lastData.setYValue(newValue);
 }

 public boolean connectArduino(String port){
 
 System.out.println("connectArduino");
 
 boolean success = false;
 SerialPort serialPort = new SerialPort(port);
 try {
 serialPort.openPort();
 serialPort.setParams(
 SerialPort.BAUDRATE_9600,
 SerialPort.DATABITS_8,
 SerialPort.STOPBITS_1,
 SerialPort.PARITY_NONE);
 serialPort.setEventsMask(MASK_RXCHAR);
 serialPort.addEventListener((SerialPortEvent serialPortEvent) -> {
 if(serialPortEvent.isRXCHAR()){
 try {
 
 byte[] b = serialPort.readBytes();
 int value = b[0] & 0xff; //convert to int
 String st = String.valueOf(value);

 //Update label in ui thread
 Platform.runLater(() -> {
 labelValue.setText(st);
 shiftSeriesData((float)value * 5/255); //in 5V scale
 });
 
 } catch (SerialPortException ex) {
 Logger.getLogger(JavaFX_jssc_Uno.class.getName())
 .log(Level.SEVERE, null, ex);
 }
 
 }
 });
 
 arduinoPort = serialPort;
 success = true;
 } catch (SerialPortException ex) {
 Logger.getLogger(JavaFX_jssc_Uno.class.getName())
 .log(Level.SEVERE, null, ex);
 System.out.println("SerialPortException: " + ex.toString());
 }

 return success;
 }
 
 public void disconnectArduino(){
 
 System.out.println("disconnectArduino()");
 if(arduinoPort != null){
 try {
 arduinoPort.removeEventListener();
 
 if(arduinoPort.isOpened()){
 arduinoPort.closePort();
 }
 
 arduinoPort = null;
 } catch (SerialPortException ex) {
 Logger.getLogger(JavaFX_jssc_Uno.class.getName())
 .log(Level.SEVERE, null, ex);
 }
 }
 }

 @Override
 public void stop() throws Exception {
 disconnectArduino();
 super.stop();
 }
 
 public static void main(String[] args) {
 launch(args);
 }
 
}

Connect a potentiometer in Arduino Uno side to set analog input A0.
Next:
- Run it remotely on Raspberry Pi 2.

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