let portName = '/dev/cu.usbmodem1441';

let inData; // for incoming serial data

let xPos = 0; // x position of the graph

​

function setup() {

  createCanvas(400, 400);

  background(0, 100, 200);

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

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

  serial.on('connected', serverConnected); // callback for connecting to the server

  serial.on('open', portOpen); // callback for the port opening

  serial.on('data', serialEvent); // callback for when new data arrives

  serial.on('error', serialError); // callback for errors

  serial.on('close', portClose); // callback for the port closing

​

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

  serial.open(portName); // open a serial port

​

​

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

}

​

  function draw() {

    graphData(inData);

  //background(0);

  //fill(255);

  //text("sensor value: " + inData, 30, 30);

}

​

​

// get the list of ports:

function printList(portList) {

  // portList is an array of serial port names

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

    // Display the list the console:

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

  }

}

​

function serverConnected() {

  console.log('connected to server.');

}

​

function portOpen() {

  console.log('the serial port opened.')

}

​

function serialEvent() {

  // read a string from the serial port:

  var inString = serial.readLine();

  // check to see that there's actually a string there:

  if (inString.length > 0 ) {

  // convert it to a number:

  inData = Number(inString);

  }

}

​

function serialError(err) {

  console.log('Something went wrong with the serial port. ' + err);

}

​

function portClose() {

  console.log('The serial port closed.');

}

function graphData(newData) {

  // map the range of the input to the window height:

  let yPos = map(newData, 0, 255, 0, height);

  // draw the line in a pretty color:

  stroke(0xA8, 0xD9, 0xA7);

  line(xPos, height, xPos, height - yPos);

  // at the edge of the screen, go back to the beginning:

  if (xPos >= width) {

    xPos = 0;

    // clear the screen by resetting the background:

    background(0x08, 0x16, 0x40);

  } else {

    // increment the horizontal position for the next reading:

    xPos++;

  }

}

​