connect to mbot through bluetooth from nodejs

show_mbot_bluetooth.js

// Based on tutorial here:
//   https://itp.nyu.edu/physcomp/labs/labs-serial-communication/lab-serial-communication-with-node-js/
// Examples:
//   node test.js /dev/tty.Makeblock-ELETSPP

var serialport = require('serialport');
var SerialPort = serialport.SerialPort;
var portName = process.argv[2];
 
// turn led green
// ff 55 09 00 02 08 07 02 00 ff 00 00
var ledGreenCmd = new Buffer([0xff, 0x55, 0x09, 0x00, 0x02, 0x08, 0x07, 0x02, 0x00, 0xff, 0x00, 0x00]);
var ledOffCmd = new Buffer([0xff, 0x55, 0x09, 0x00, 0x02, 0x08, 0x07, 0x02, 0x00, 0x00, 0x00, 0x00]);

var myPort = new SerialPort(portName, {
   baudRate: 115200,  // baud rate for makeblock.
   parser: serialport.parsers.readline("\n")
 });

myPort.on('open', showPortOpen);
myPort.on('data', showSerialData);
myPort.on('close', showPortClose);
myPort.on('error', showError);

function showPortOpen() {
  console.log('port open. Data rate: ' + myPort.options.baudRate);
  changeLedAndClose();
}

function showSerialData(data) {
  console.log(new Buffer(data));
}
 
function showPortClose() {
  console.log('port closed.');
}
 
function showError(error) {
  console.log('Serial port error: ' + error);
}

function changeLedAndClose() {
  myPort.write(ledGreenCmd);
  setTimeout(function() {
    console.log('turn off light');
    myPort.write(ledOffCmd);
    console.log('close port ....')
    myPort.close(); 
  }, 3000);
}