​

function setup() {

  createCanvas(640, 480);

  textSize(18);

  slider = createSlider(0, 255);

  slider.position(width/2, height/2);

  slider.size(80);

}

​

function draw() {

  background('white')

​

  if (!serialActive) {

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

  } else {

    text("Connected", 20, 30);

  }

  text("brightness: " + str(brightness), 150, height/2+15);

​

  brightness = slider.value();

​

}

​

function keyPressed() {

  if (key == " ") {

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

    setUpSerial();

  }

}

​

// This function will be called by the web-serial library

// with each new *line* of data. The serial library reads

// the data until the newline and then gives it to us through

// this callback function

​

function readSerial(data) {

  let sendToArduino = brightness + "\n";

  writeSerial(sendToArduino);

​

}