​

function setup() {

  createCanvas(400, 400);

  osc = new p5.Oscillator();

  osc.start();

  osc.freq(200); // Sets oscillator frequency to 200

  osc.freq(800, 2); // Ramps frequency to 800 over 2 seconds

}

​

function draw() {

  background(220);

  if(osc.getFreq() == 800){ // If frequency is 800...

    osc.freq(200, 2); // ramp frequency to 200Hz over 2 seconds

  }

   if(osc.getFreq() == 200){ // If frequency is 200...

    osc.freq(800, 2); // ramp frequency to 800Hz over 2 seconds

  }

}