let alpha = 255;

​

​

function setup() {

  createCanvas(640, 480);

  textSize(18);

}

​

function draw() {

​

  background(255);

  if (!serialActive) {

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

  } else {

    // Print the current values

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

    //text('alpha = ' + str(alpha), 20, 70);

  }

  let xpos = map(rVal, 0, 1023, 0, width);  // Map the sensor value to the canvas width

  ellipse(xpos, height / 2, 50, 50);  // Draw an ellipse at the mapped position

}

​

function keyPressed() {

  if (key == " ") {

    // important to have in order to start the serial connection!!

    setUpSerial();

  }

}

function readSerial(data) {

  ////////////////////////////////////

  //READ FROM ARDUINO HERE

  ////////////////////////////////////

​

  if (data != null) {

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

    // if the right length, then proceed

    if (fromArduino.length == 1) {

      rVal = int(fromArduino[0]);

    }

​

  }

}

​

​

​

​

​