example.js

// ADSR ~ Attack, Sustain, Decay, Release
var attackLevel = 1.0;
var releaseLevel = 0;

var attackTime = 0.001;
var decayTime = 0.2;
var susPercent = 0.2;
var releaseTime = 0.5;

var env, triOsc;

function setupAudio() {
  env = new p5.Env();
  env.setADSR(attackTime, decayTime, susPercent, releaseTime);
  env.setRange(attackLevel, releaseLevel);

  triOsc = new p5.Oscillator('triangle');
  triOsc.amp(env);
  triOsc.start();
  triOsc.freq(220);
}

function setup() {
  var cnv = createCanvas(100, 100);
  setupAudio();
}

function keyPressed () {
	if (key === 'A') {
		triOsc.freq(220);
		env.play(triOsc, 0, 0.2);
	}
	else if (key === 'S') {
		triOsc.freq(330);
		env.play(triOsc, 0, 0.2);
	}
}