var bg = 0;

​

function setup() {

  // Instantiate our SerialPort object

  serial = new p5.SerialPort();

    createCanvas(400, 400);

  // Let's list the ports available

  var portlist = serial.list();

​

  // Assuming our Arduino is connected, let's open the connection to it

  // Change this to the name of your arduino's serial port

  serial.open("/dev/cu.usbmodem1441");

​

  // Register some callbacks

​

  // When we connect to the underlying server

  serial.on('connected', serverConnected);

​

  // When we get a list of serial ports that are available

  serial.on('list', gotList);

​

  // When we some data from the serial port

  serial.on('data', gotData);

​

  // When or if we get an error

  serial.on('error', gotError);

​

  // When our serial port is opened and ready for read/write

  serial.on('open', gotOpen);

}

​

// We are connected and ready to go

function serverConnected() {

    print("We are connected!");

}

​

// Got the list of ports

function gotList(thelist) {

  // theList is an array of their names

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

    // Display in the console

    print(i + " " + thelist[i]);

  }

}

​

// Connected to our serial device

function gotOpen() {

  print("Serial Port is open!");

}

​

// Ut oh, here is an error, let's log it

function gotError(theerror) {

  print(theerror);

}

​

// There is data available to work with from the serial port

function gotData() {

  var currentString = serial.readStringUntil("\r\n");

  if (currentString){

    console.log(currentString);

  bg = int(currentString);

  }

}

​

// Methods available

// serial.read() returns a single byte of data (first in the buffer)

// serial.readChar() returns a single char 'A', 'a'

// serial.readBytes() returns all of the data available as an array of bytes

// serial.readBytesUntil('\n') returns all of the data available until a '\n' (line break) is encountered

// serial.readString() retunrs all of the data available as a string

// serial.readStringUntil('\n') returns all of the data available as a tring until a (line break) is encountered

// serial.last() returns the last byte of data from the buffer

// serial.lastChar() returns the last byte of data from the buffer as a char

// serial.clear() clears the underlying serial buffer

// serial.available() returns the number of bytes available in the buffer

function draw() {

  background(bg);

}