JS on Single-board computer

Node.js (ARM / MIPS) running on a tiny computer
with GPIO and wireless capabilities!

GPIO is general-purpose input/output pin on a chip or computer board

JS on micro-controllers

Hardware: Tessel & Servo

Software: JavaScript

					
// File: index.js
// Run: t2 push index.js

var tessel = require('tessel')
var servoPin = tessel.port.A.pwm[0]
var app = require('express')()
var angle = 0
...

tessel.pwmFrequency(50)
servoPin.pwmDutyCycle(1/20)

app.get('/turn', function (req, res) {
  angle += 30
  servoPin.pwmDutyCycle(((angle)/180 + 1)/20) // move the servo
  ...
})
					
				

Practical application: Robotics

OpenROV plugin thrusters in node.js

Explore

Firmata is a protocol for communicating with
microcontrollers

Abstraction: Tethered app

Demo

Hardware: Neopixel & Arduino

Software: JavaScript

					
var five = require('johnny-five')
var pixel = require('node-pixel')
var board = new five.Board({ port: 8000 })

board.on('ready', function() {
  ring = new pixel.Strip({
    data: 6,
    length: 60,
    color_order: pixel.COLOR_ORDER.GRB,
    board: this,
    controller: 'FIRMATA',
  })

  ring.on('ready', function() {
    app.get('/red', function(req, res) {
      ring.color('#100')
      ring.show()
      res.redirect('/')
    })
...
					
				

Examples of Firmata

Use nodebots-interchange to flash
custom firmata in your boards!

Explore

Wireless Technologies

Low cost, low powered sensors running for years

IoT platforms talk to devices via the Internet protocol through gateways

Demo

IoT platform: get sensor data, visualise data, interpret data

Hardware: TI Sensor Tag

Software: Node.js

						
var SensorTag = require('sensortag')
var app = require('express')()
var async = require('async')
var WebSocketServer = require('ws').Server
...
SensorTag.discover(function(sensorTag) {
   async.series([
      function(callback) {
        console.log('Connected to Sensor Tag')
        sensorTag.connectAndSetUp(callback)
      },

      function(callback) { sensorTag.enableIrTemperature(callback); },
      function(callback) { setTimeout(callback, 2000); },
      function(callback) {
        sensorTag.readIrTemperature(function(error, objectTemperature, ambientTemperature) {
          console.log('Temperature = %d °C', ambientTemperature.toFixed(1))
          callback();
        });
...
						
				

Explore: IoT Platform

One day Alice came to a fork in the road and saw a Cheshire cat in the tree.

"Which road should I take?" she asked.

"Where do you want to go?" was his response.

"I don't know" Alice answered.

"Then", said the cat,
"it doesn't matter"

References & Credits 📚

1. Tessel 2 servo example
2. Digital-first vs Physical-first
3. Adafruit Neopixel Uberguide
4. TI Sensor Tag hardware