// arduino code can be found here : https://gist.github.com/shfitz/b78b412960fba668d08ccc84b9ee838d

​

let serial; // variable for the serial object

let latestData = "waiting for data"; // variable to hold the data

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  // serial constructor

  serial = new p5.SerialPort();

​

  // serial port to use - you'll need to change this

  serial.open('/dev/tty.usbmodem143201');

​

  // what to do when we get serial data

  serial.on('data', gotData);

​

}

​

// when data is received in the serial buffer

​

function gotData() {

  let currentString = serial.readLine(); // store the data in a variable

  trim(currentString); // get rid of whitespace

  if (!currentString) return; // if there's nothing in there, ignore it

  console.log(currentString); // print it out

  latestData = currentString; // save it to the global variable

}

​

function draw() {

  background(255, 255, 255);

  fill(0, 0, 0);

  text(latestData, 10, 10); // print the data to the sketch

​

  // in this example, we are reciving a value between 0 and 1023

  // and using that to rotate the square

  angleMode(DEGREES);

  let rotDeg = map(latestData, 0, 1023, 0. ,360.);

​

  translate(width / 2, height / 2);

  rotate(rotDeg);

  rectMode(CENTER);

  rect(0, 0, 100, 100);

​

​

}