var sensorValue = 0;        // ellipse position

​

function setup() {

  createCanvas(320, 240);

  serial = new p5.SerialPort();  // make a new instance of  serialport library

  serial.on('list', printList);  // callback function for serialport list event

  serial.on('data', serialEvent);// callback for new data coming in

    serial.list();                         // list the serial ports

    serial.open("COM6"); // open a port

}

​

function draw() {

  background("#2307AF");

  fill(255);

  if (sensorValue !== 0) {

    ellipse(width/2, height/2, 20, 20);

  }

  text(sensorValue, 20, 20);

}

​

// get the list of ports:

function printList(portList) {

 for (var i = 0; i < portList.length; i++) {

    // Display the list the console:

    println(i + " " + portList[i]);

 }

}

​

function serialEvent() {

    var inString = serial.readLine();

    if (inString.length > 0) {

      inString = inString.trim();

        sensorValue = Number(inString/4);

    }

}

​