Communication between Arduino and PC running Java, with JavaFX UI

Last posts "Setup RxTx for Arduino and Java example" and "Create Java project using librxtx-java in Netbeans, work with Arduino" describe basic setup to program Java with RxTx library in Netbeans, to receive data from Arduino Due. In this post, I will show bi-direction communication between Arduino Due and PC running Java, with JavaFX user interface.

Communication between Arduino and PC running Java, with JavaFX UI

User enter message in JavaFX and click the button, the message will be sent to Arduino via Serial. In Arduino side, it loop back the message to PC. Then, if received in PC side, it will be displayed in JavaFX.



It's a very simple code in Arduino side:

void setup() {
  Serial.begin(9600);
}

void loop() {
  if(Serial.available() > 0){
    Serial.print((char)Serial.read());
  }
}

In PC side, it's modified from last post, implement in JavaFX, with bi-direction communication.

package javafx_arduinotestserial;

import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

/**
 * @web arduino-er.blogspot.com
 */
public class JavaFX_ArduinoTestSerial extends Application {

    MyRxTx myRxTx;
    Label textInfo, textIn;

    @Override
    public void start(Stage primaryStage) {

        final TextField textOut = new TextField();
        textOut.setText("Hello Arduino-er!");

        textInfo = new Label();
        textIn = new Label();

        Button btn = new Button();
        btn.setText("Say 'Hello World'");
        btn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                String stringOut = textOut.getText() + "\r\n";

                try {
                    myRxTx.output.write(stringOut.getBytes());
                } catch (IOException ex) {
                    Logger.getLogger(
                            JavaFX_ArduinoTestSerial.class.getName())
                            .log(Level.SEVERE, null, ex);
                }
            }
        });

        VBox panel = new VBox(10);
        panel.setPadding(new Insets(10, 10, 10, 10));
        panel.getChildren().addAll(textInfo, textOut, btn, textIn);

        StackPane root = new StackPane();
        root.getChildren().add(panel);

        Scene scene = new Scene(root, 300, 250);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();

        myRxTx = new MyRxTx();
        myRxTx.initialize();
    }

    public static void main(String[] args) {
        launch(args);
    }

    class MyRxTx implements SerialPortEventListener {

        SerialPort serialPort;
        /**
         * The port we're normally going to use.
         */
        private final String PORT_NAMES[] = {
            "/dev/ttyACM0", //for Ubuntu
            "/dev/tty.usbserial-A9007UX1", // Mac OS X
            "/dev/ttyUSB0", // Linux
            "COM3", // Windows
        };
        private BufferedReader input;
        private OutputStream output;
        private static final int TIME_OUT = 2000;
        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;
            } else {
                textInfo.setText("Port Name: " + portId.getName() + "\n"
                        + "Current Owner: " + portId.getCurrentOwner() + "\n"
                        + "Port Type: " + portId.getPortType());
            }

            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();

                // add event listeners
                serialPort.addEventListener(this);
                serialPort.notifyOnDataAvailable(true);
            } catch (Exception e) {
                System.err.println(e.toString());
            }
        }

        @Override
        public void serialEvent(SerialPortEvent spe) {
            if (spe.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
                try {
                    final String inputLine = input.readLine();

                    Platform.runLater(new Runnable() {
                        @Override
                        public void run() {
                            textIn.setText(inputLine);
                        }
                    });

                    System.out.println(inputLine);
                } 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();
            }
        }
    }
}