function setup() {

  createCanvas(640, 480);

  textSize(18);

  ellipseHorizental = width/2; 

}

function draw() {

  background(220);

  // Draw ellipse with width based on potentiometer value

  fill("green");

  ellipse(ellipseHorizental, height / 2, 100, 150);

  if (!serialActive) {

    text("Press Space Bar to select Serial Port", 20, 30);

  } else {

    text("Connected", 20, 30);

    // Print the current potentiometer value

    text('Potentiometer Value = ' + str(ellipseHorizental), 20, 50);

  }

}

function keyPressed() {

  if (key == " ") {

    setUpSerial();

  }

}

function readSerial(data) {

  if (data != null) {

    // convert the string to a number using int()

    let fromArduino = split(trim(data), ",");

    // Map the potentiometer value to the ellipse width

    ellipseHorizental = map(int(fromArduino[0]), 0, 1023, 0, 640); 

  }

}