Piezo - lyzadanger/johnny-five GitHub Wiki

The Piezo class constructs objects that represent a single piezo component attached to the physical board.

Parameters

pin A Number or String address for the Piezo (+) pin (digital):

var piezo = new five.Piezo(3);

options An object of property parameters.

Property Name	Type	Value(s)	Description	Required
pin	Number	Any Digital Pin	The Number address of the pin the + input your piezo is attached to	yes

```js var piezo = new five.Piezo({ pin: 3 }); ```

Shape

{ 
  board: ...A reference to the board object the Led is attached to
  id: ...A user definable id value. Defaults to null
  pin: ...The pin address that the Led is attached to
  mode: ...Mode the piezo's pin is set to: output (1). READONLY
  isPlaying: ...Boolean: is the piezo currently playing?
}

Usage

var five = require("johnny-five"), 
    board = new five.Board();

board.on("ready", function() {

  // Create a standard `piezo` instance on pin 3
  var piezo = new five.Piezo(3);

  // Inject piezo object into REPL session
  this.repl.inject({
    piezo: piezo
  });
});

API

frequency(frequency, duration) Play tone at frequency (in Hz) for duration milliseconds.

var piezo = new five.Piezo(3);
piezo.frequency(587, 1000); // Play note d5 for 1 second

play(tune, callback) Play a tune with an optional callback to invoke when the tune is done playing. The tune object contains a song (an array of the notes in the tune) and optional settings (e.g. tempo):

var piezo = new five.Piezo(3);
piezo.play({
      tempo: 150, // Beats per minute, default 150
      song: [ // An array of notes that comprise the tune
        [ "c4", 1 ], // Each element is an array in which 
                     // [0] is the note to play and 
                     //[1] is the duration in "beats" (tempo, above)
        [ "e4", 2],
        [ "g4", 3],
        [ null, 4 ] // null indicates "no tone" for the beats indicated
     ]
    };

The notes you can use are defined in lib/piezo.js as Piezo.Notes:

Piezo.Notes = {
  "c4": 262,
  "c#4": 277,
  "d4": 294,
  "d#4": 311,
  "e4": 330,
  "f4": 349,
  "f#4": 370,
  "g4": 392,
  "g#4": 415,
  "a4": 440,
  "a#4": 466,
  "b4": 494,
  "c5": 523,
  "c#5": 554,
  "d5": 587,
  "d#5": 622,
  "e5": 659,
  "f5": 698,
  "f#5": 740,
  "g5": 784,
  "g#5": 831,
  "a5": 880,
  "a#5": 932,
  "b5": 988,
  "c6": 1047
};

You can also use frequencies directly if you'd like:

var piezo = new five.Piezo(3);
piezo.play({
      song: [
        [ 698, 1 ], // Play frequency 698 for 1 beat
        [ 831, 2] // ...
     ]
    };

tone(frequency, duration) Play a tone for duration ms. The tone value in this case is a computed duty cycle (in microseconds). This is a lower-level method than frequency (which does the translation from frequency to tone for you). Most of the time you likely want to use frequency.
noTone Stop tone playing from Piezo. Will immediately stop playing a tone (digitalWrite the output pin low) and clear any existing queued tone timers.
off Alias of noTone

Events

Piezo objects are output only and therefore do not emit any events.

Examples

Piezo