Espruino Star Wars (first steps)

@Gordon,

Thanks for suggesion regarding connecting both sides of seaker to PWM outputs!
It works nice. We tried to play with the same tunes for Star Wars. It sounds very different now, but still very special, so we decided to share it with you again:
https://vimeo.com/127748913

Not bad techno music for my taste :)

Also, this time I feel ready to share the code for this demo (still not perfect though), maybe it will help somebody.

BUZZER1 = B6;
BUZZER2 = B7;

BUZZER3 = B4;
BUZZER4 = B5;

function freq(buz, f) {
  if (f===0) digitalWrite(buz,0);
  else analogWrite(buz, 0.5, { freq: f } );
}

var pitches = {
  'a':220.00,
  'b':246.94,
  'c':261.63,
  'd':293.66,
  'e':329.63,
  'f':349.23,
  'g':392.00,
  'A':440.00,
  'B':493.88,
  'C':523.25,
  'D':587.33,
  'E':659.26,
  'F':698.46,
  'G':783.99,
  'H':830.60
};


function Buzzer(pin, tune, led, wave) {
  this.pin = pin;
  this.tune = tune;
  this.led = led;
  this.pos = 0;
  this.wave = wave;
}

Buzzer.prototype.reset = function() {
  this.pos = 0;
};

Buzzer.prototype.step = function() {
  var ch = this.tune[this.pos];
  if (ch !== undefined) {
    this.pos++;
    print(this.pin+","+ch);
  }
  if (ch in pitches) {
    if(this.wave!==undefined) {
      wave(this.pin, this.wave, pitches[ch]);
    } else {
      freq(this.pin, pitches[ch]);
    }
    digitalWrite(this.led, 1);
  }
  else {
    if(this.wave!==undefined) {
      wave(this.pin, this.wave, 0); //off
    } else {
      freq(this.pin, 0); //off
    }
    digitalWrite(this.led, 0);
  }
};

//           .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   "
var tune1  = "AA  AA  AA  ff CAA  ff CAAAA    EE  EE  EE  HH ECC  ff CAAAA";
var tune2  = "a a a a a a a a a a a a f f g g a a a a f f g g a a a a a a a a e e e e e e e e e e e e g g f f c c c c f f g g a a a a aaaaaaaa";
var tempo = 150;
var tempo1 = 2*tempo;
var tempo2 = tempo;
var tempo3 = tempo;
var tempo4 = 2*tempo;

var buzzer1 = new Buzzer(BUZZER1, tune1, LED1, w1);
var buzzer2 = new Buzzer(BUZZER2, tune2, LED2, w2);

var buzzer3 = new Buzzer(BUZZER3, tune1, B15, w1);
var buzzer4 = new Buzzer(BUZZER4, tune2, B14, w2);

function resetTune() {
  buzzer1.reset();
  buzzer2.reset();
  buzzer3.reset();
  buzzer4.reset();
}

function initAudioAndLED() {
  setInterval( function() { buzzer1.step();}, tempo1);
  setInterval( function() { buzzer2.step();}, tempo2);
  setInterval( function() { buzzer3.step();}, tempo3);
  setInterval( function() { buzzer4.step();}, tempo4);
  var resetInterval = Math.max(tune1.length*tempo1, tune2.length*tempo2);
  setInterval(resetTune, resetInterval);
}

function onInit() {
  initAudioAndLED();
}

onInit();
// save();

The result was achieved pretty quickly, making me confident we can play even better tunes in future.

Thanks,
Victor