let portName = '/dev/tty.usbserial-1410';  // fill in your serial port name here

let inData;

let xPos = 0;

function setup() {

  createCanvas(300,300);

  background(0);

  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

}

​

function draw(){

  // background(0);

  // fill(255);

  // textSize(20);

  // text("value: "+inData,100,150);

  // ellipse(150,150,inData,inData);

  graphData(inData);

}

​

function graphData(newData) {

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

  var 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++;

  }

}

​

function printList(portList) {

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

    console.log(i + portList[i]);

  }

}

​

function serverConnected() {

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

}

function portOpen() {

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

}

function serialEvent() {

  let inString=serial.readLine();

  if(inString.length>0){

     inData=Number(inString);

     }

}

function serialError(err) {

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

}

function portClose() {

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

}