Buzzer

Description

The Buzzer is a template class, that you can use in your own Java-project.

The Template Class gives you the option to play a note, and to create your own little melodies to play. The buzzer is controlled via a PWM output. The dutycycle is fixed at 50% and with the frequency the desired sound can be reproduced.

Layout

Buzzer Layout

Code

A simple example on how to use the Buzzer-Class from the Hardware-Catalog:

public class Buzzer_App implements Application {

    //this is how you compose a simple melody
    //Piano baseline of Seven Nation Army by the white Stripes
    private final List<Buzzer.Sound> melody = List.of(
            new Buzzer.Sound(E7   , 11),
            new Buzzer.Sound(PAUSE, 1),
            new Buzzer.Sound(E7   , 2),
            new Buzzer.Sound(PAUSE, 2),
            new Buzzer.Sound(G6   , 2),
            new Buzzer.Sound(PAUSE, 3),
            new Buzzer.Sound(E7   , 2),
            new Buzzer.Sound(PAUSE, 4),
            new Buzzer.Sound(D6   , 2),
            new Buzzer.Sound(PAUSE, 3),
            new Buzzer.Sound(C7   , 16),
            new Buzzer.Sound(B5   , 8),
            new Buzzer.Sound(PAUSE, 8)
    );

    private final List<Buzzer.Sound> imperialMarch = List.of(
            new Buzzer.Sound(G4,  8),
            new Buzzer.Sound(G4,  8),
            new Buzzer.Sound(G4,  8),
            new Buzzer.Sound(DS4, 6),
            new Buzzer.Sound(AS4, 2),
            new Buzzer.Sound(G4,  8),
            new Buzzer.Sound(DS4, 6),
            new Buzzer.Sound(AS4, 2),
            new Buzzer.Sound(G4, 16));

    @Override
    public void execute(Context pi4j) {
        System.out.println("Buzzer demo started");

        //initialising the buzzer
        Buzzer buzzer = new Buzzer(pi4j, PIN.PWM13);

        //playing a simple tone
        System.out.println("playing note b6 for 1 sec");
        buzzer.playTone(1976, Duration.ofSeconds(1));

        //relax for 1 second
        buzzer.silence(Duration.ofSeconds(1));

        System.out.println("start playing melody");
        buzzer.playMelody(60, melody);

        delay(Duration.ofSeconds(3));

        //first melody is stopped and second is played
        buzzer.playMelody(103, imperialMarch);

        buzzer.awaitEndOfMelody();
        System.out.println("Second melody has finished");

        buzzer.reset();

        System.out.println("buzzer demo finished");
    }
}

Further application

The class is implemented in the sample project Theremin.

Further project ideas

  • An application, which triggers if you walk by and starts beeping, like an alarm.
  • An application, where you use many of them to create a beautiful sounding melody.