let connectBtn;

let strCont =0;

let nombre;

​

function setup() {

  createCanvas(400, 400);

  background(220);

  port = createSerial();

​

  let usedPorts = usedSerialPorts();

  if (usedPorts.length > 0) {

    port.open(usedPorts[0], 57600);

  }

  connectBtn = createButton('Connect to Arduino');

  connectBtn.position(10, 10);

  connectBtn.mousePressed(connectBtnClick);

}

​

function draw() {

  background(220);

​

​

  // reads in complete lines and prints them at the

  // bottom of the canvas

  nombre = port.readUntil("\n");

  if (nombre.length > 0) {

   strCont = nombre;

  }

​

  text(strCont, 10, height-20);

    ellipse(200,200, strCont, strCont);

  // changes button label based on connection status

  if (!port.opened()) {

    connectBtn.html('Connect to Arduino');

  } else {

    connectBtn.html('Disconnect');

  }

}

​

function connectBtnClick() {

  if (!port.opened()) {

    port.open('Arduino', 57600);

  } else {

    port.close();

  }

}

​