let y = 100;

let inkrement = 5;

​

function setup() {

  createCanvas(300, 300);

}

​

function draw() {

  y = y + inkrement;

​

  if ((y < r/2) || (y > width - r/2)) {

    inkrement = -inkrement;

  }

  background(0);

  stroke(255);

  strokeWeight(5);

  fill(255, 181, 0);

  circle(150, y, r);

  noStroke();

  fill(255);

  textSize(18);

  let txt = "y: " + y + ", ink: " + inkrement;

  text(txt, 18, 30);

}