Wednesday, September 9, 2015

JavaFX + jSSC - read byte from Arduino Uno, display in LineChart


Similar to last example "JavaFX + jSSC - read byte from Arduino Uno, read from Analog Input". This example plot the analog data in JavaFX LineChart. (This video show the effect of calling lineChart.setAnimated(false) and default true also.)


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

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.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
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;
    
    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);
            }

        });
        
        //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, 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();
    }
    
    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();
                }
                
            } 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);
    }
    
}


For the Arduino Uno side and hardware connection, refer to last post "JavaFX + jSSC - read byte from Arduino Uno, read from Analog Input".

Next:
Bi-direction communication between Arduino and PC using Java + jSSC

1 comment:

  1. why can't mine continuously graph and then it states at the console that Exception in thread "EventThread COM8" java.lang.NullPointerException
    at javafx_jssc_uno.JavaFX_jssc_Uno.lambda$connectArduino$1(JavaFX_jssc_Uno.java:137)
    at jssc.SerialPort$EventThread.run(SerialPort.java:1112)

    Please help me... it's really important and sorry if i'm reaaly new to java...

    ReplyDelete