[ev3 × Java] Display, sound, LED control

This article is for anyone who wants to work with ev3 in Java. This time, I would like to use intelligent blocks to display text, make sounds, and control LEDs.

table of contents

0. What to prepare
1. Display
2. Sound 3 . LED Finally

0. What to prepare

◯ ev3 (intelligent block) ◯ Personal computer (VS Code) ◯ bluetooth ◯ microSD ◯ API Documentation (It is recommended to proceed while watching this.)

1. Display

1-0. Basic display program ①

◯ It is a program that displays characters for 3 seconds.

display00.Java

import lejos.utility.Delay;

public class Display00
{
    public static void main(String[] args)
    {
        System.out.println("Hello World!!");
        Delay.msDelay(3000);
    }
}

1-1. Basic display program ②

◯ It is a program that can change the place and font to display the text.

display01.java

import lejos.hardware.lcd.Font;
import lejos.hardware.lcd.GraphicsLCD;
import lejos.hardware.ev3.LocalEV3;
import lejos.utility.Delay;


public class Display01 {

    public static void main(String[] args) {

    	GraphicsLCD g = LocalEV3.get().getGraphicsLCD();
        final int SW = g.getWidth();
        final int SH = g.getHeight();
    	
		g.drawString("Hello World", 5, 0, 0);
		Delay.msDelay(3000);
		g.setFont(Font.getSmallFont());
		g.drawString("Programming is so fantastic!!", 2, 20, 0);
		Delay.msDelay(3000);
        g.drawString("Good BYE", SW/2, SH/2, 0);
		Delay.msDelay(1000);
    }
}

Point: ** drawString method ** void drawString(java.lang.String str,int x,int y,boolean inverted)

Point:Font

Point: ** Interface Graphics LCD **

1-2. Basic display program ③

◯ It is a program that displays figures.

display02.java

import lejos.hardware.lcd.GraphicsLCD;
import lejos.hardware.ev3.LocalEV3;
import lejos.utility.Delay;


public class Display01 {

    public static void main(String[] args) {

    	GraphicsLCD g = LocalEV3.get().getGraphicsLCD();
        final int SW = g.getWidth();
        final int SH = g.getHeight();
  
        g.drawChar('A', 30, 30, 0);
        g.drawRect(0,0,100,100);
        g.fillRect(SW/2,SH/2,50,50);
        Delay.msDelay(3000);
    }
}

Point:getGraphicsLCD Get graphics access to the LCD Returns:the graphics LCD

Point: ** drawRect method ** void drawRect(int x,int y,int width,int height)

2. Sound

2-0. Basic sound program ①

◯ It is a program that makes various sounds.

Sound00.java

import lejos.hardware.Sound;

public class Sound00
{
    public static void main(String[] args)
    {
        Sound.beep();
        Sound.buzz();
        Sound.systemSound(true,2);
    }
}

Point: ** Sound class methods **

2-1. Basic sound program ②

◯ It is a program that adjusts the frequency and produces sound.

Sound01.java

import lejos.hardware.Sound;

public class Sound01
{
    public static void main(String[] args)
    {
    	Sound.playTone(262, 500);//Do
    	Sound.playTone(294, 500);//Re
    	Sound.playTone(330, 500);//Mi
    	Sound.playTone(349, 500);//Fa
    	Sound.playTone(392, 500);//So
    }
}

Point: ** Scale frequency **

3.LED

3-0. Basic LED program

◯ Colors can be displayed in various patterns.

led00.java

import lejos.hardware.Button;
import lejos.utility.Delay;

public class LED00 {

    public static void main(String[] args) {

    	for (int i = 0;i < 10;i++) {
    		System.out.println(i);
    		Button.LEDPattern(i);
    		Delay.msDelay(3000);
    	}
    }
}

Finally

Thank you for reading! !! Next time, I would like to write about intelligent block buttons!

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