// arduino code can be found here : https://gist.github.com/shfitz/7fd206b7db4e0e6416a443d61c8c988e

​

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();

  // get a list of all connected serial devices

  serial.list();

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

  serial.open('/dev/tty.usbmodem1423201');

  // callback for when the sketchs connects to the server

  serial.on('connected', serverConnected);

  // callback to print the list of serial devices

  serial.on('list', gotList);

  // what to do when we get serial data

  serial.on('data', gotData);

  // what to do when there's an error

  serial.on('error', gotError);

  // when to do when the serial port opens

  serial.on('open', gotOpen);

  // what to do when the port closes

  serial.on('close', gotClose);

}

​

function serverConnected() {

  console.log("Connected to Server");

}

​

// list the ports

function gotList(thelist) {

  console.log("List of Serial Ports:");

​

  for (let i = 0; i < thelist.length; i++) {

    console.log(i + " " + thelist[i]);

  }

}

​

function gotOpen() {

  console.log("Serial Port is Open");

}

​

function gotClose() {

  console.log("Serial Port is Closed");

  latestData = "Serial Port is Closed";

}

​

function gotError(theerror) {

  console.log(theerror);

}

​

// 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 0 and a 1

  // if the button is not pressed we get a 0

  if (latestData == 0) {

    ellipse(width / 2, height / 2, 100, 100);

  } else { // if it is pressed, we get a 1

    rectMode(CENTER);

    rect(width / 2, height / 2, 100, 100);

  }

}