@girlie_mac Hardware Hacking for JavaScript Devs Tomomi Imura (@girlie_mac) Hardware Hacking for JavaScript Devs https://flic.kr/p/8tuc1u by randomliteraturecouncil CC-BY 2.0 

@girlie_mac 

@girlie_mac I am a: ● Front-End Engineer ● N00b Hardware Hacker ● Sr. Developer Evangelist at PubNub 

@girlie_mac 

@girlie_mac Era of Internet of Things Source: Cisco IBSG https://www.cisco.com/web/about/ac79/docs/innov/IoT_IBSG_0411FINAL.pdf 

@girlie_mac Withings: Smart Body Analyzer GE Link Cinder Sensing Cooker Nest: Learning Thermostat Whistle: Connected pet collar Amazon Dash Button 

@girlie_mac Thermostats get Internet! Bulbs get Internet! Everything gets Internet! 

@girlie_mac OK, connect me with InterWeb... Srsly, where should I start? 

@girlie_mac Arduino ● MCU-based kit ● Open-Source hardware & software (IDE) ● The first developer-friendly boards 

@girlie_mac Arduino USB PLUG TO COMPUTER EXTERNAL POWER SOURCE GPIO DIGITAL PINS ANALOG PINS 

@girlie_mac LittleBits 

@girlie_mac LittleBits & Arduino at Heart 9V BATTERY USB PLUG TO COMPUTER MODULES 

@girlie_mac Arduino-Compatible MCUs BeagleBone C.H.I.P mCookie Petduino LinkIt One 

@girlie_mac Tessel USB PLUGS TO COMPUTER ETHERNET MODULES GPIO DIGITAL PINS EXTRA USB PORTS 

@girlie_mac Programming Tessel in Node.js var tessel = require('tessel'); var camera = require('camera-vc0706').use(tessel.port['A']); camera.on('ready', function() { camera.takePicture(function(err, image) { if (err) { console.log(err); } else { var name = 'pic-' + Date.now() + '.jpg'; process.sendfile(name, image); camera.disable(); } }); }); the port the camera module is plugged in ready event callback 

@girlie_mac Selfie with Tessel! 

@girlie_mac Raspberry Pi USB TO POWER SOURCE TO MONITOR TO MOUSE TO KEYBOARD WI-FI ADAPTER SD CARD GPIO DIGITAL PINS 4 EXTRA USB PORTS ETHERNET 

@girlie_mac Raspbian OS 

@girlie_mac Programming Raspberry Pi Pre-installed on RPi: C / C++ 

@girlie_mac LED: Hello World of Hardware 

@girlie_mac Circuit 3.3V (Raspberry Pi) LED 

@girlie_mac Ohm’s Law & Resistors R = V - V s f I source voltage (V) forward voltage (V) (LED voltage drop) current thru the LED (A) resistance (Ω) 

@girlie_mac Ohm’s Law & Resistors R = 3.3 - 1.9 0.02 source voltage (V) forward voltage (V) (LED voltage drop) current thru the LED (A) resistance (Ω) = 70Ω 

@girlie_mac Circuit 3.3V (Pin 1) GND Anode (longer leg) Cathode 

@girlie_mac Making LED Programmable GPIO-4 (Pin 7) 

@girlie_mac Programming MCU with Node.js 

@girlie_mac Programming Pi with Node.js Download & install Node.js with node-arm: $ wget http://node-arm.herokuapp. com/node_latest_armhf.deb $ sudo dpkg -i node_latest_armhf.deb 

@girlie_mac Johnny-Five ● JavaScript robotics framework ● Works with Arduino-compatible Boards ● IO plugins for more platform supports ● http://johnny-five.io/ Woot! 

@girlie_mac Johnny-Five & Raspi-io npm install johnny-five npm install raspi-io 

@girlie_mac Blinking LED var five = require('johnny-five'); var raspi = require('raspi-io'); var board = new five.Board({io: new raspi()}); board.on('ready', function() { var led = new five.Led(7); // Create an instance led.blink(500); // "blink" in 500ms on-off phase periods }); Pin 7 (GPIO-4) Plugin for RPI (Default w/o plugins works for all Arduino) 

@girlie_mac Prototyping Smart Stuff 

@girlie_mac Streaming Data Data streaming among devices w/ PubNub 

@girlie_mac Sending Data from browser var pubnub = PUBNUB.init({ subscribe_key: 'sub-c-...', publish_key: 'pub-c-...' }); function lightOn() { pubnub.publish({ channel: 'remote-led', message: {light: true}, callback: function(m) {console.log(m);}, error: function(err) {console.log(err);} }); } document.querySelector('button') .addEventListener('click', lightOn); button click 

@girlie_mac Receiving Data to MCU var pubnub = require('pubnub').init({ subscribe_key: 'sub-c-...', publish_key: 'pub-c-...' }); pubnub.subscribe({ channel: channel, callback: function(m) { if(m.blink) { // blink LED } } }); led.pulse(); 

@girlie_mac Prototyping Hue-clone w/ RGB LED Common cathode LED R G B GND PWM pins 

@girlie_mac Prototyping Hue-clone w/ RGB LED {'red':215, 'green':50, 'blue':255} publish data subscribe data Software UI Physical Output 

@girlie_mac Sending Data from browser redInput.addEventListener('change', function(e){ publishUpdate({color: 'red', brightness: +this.value}); }, false); function publishUpdate(data) { pubnub.publish({ channel: 'hue', message: data }); } Send the red value to PubNub to tell the MCU to reflect the change! the value has changed! Publish the new value! 

@girlie_mac Receiving Data to LED pubnub.subscribe({ channel: 'hue', callback: function(m) { if(led) { r = (m.color === 'red') ? m.brightness : r; g = (m.color === 'green') ? m.brightness : g; b = (m.color === 'blue') ? m.brightness : b; led.color({red: r, blue: b, green: g}); } } }); to the GPIO pins that connect to LED anodes 

@girlie_mac Prototyping Smart Light Bulbs 

@girlie_mac KittyCam 

@girlie_mac 

@girlie_mac KittyCam in Node.js 1. Detect motion (Johnny-Five IR.Motion obj) 2. Take photos (Raspistill, command line tool) 3. Cat facial detection (KittyDar) 4. Store the photos in Cloudinary 5. Publish the data to PubNub 6. Stream on web (subscribe the data from PubNub) 

@girlie_mac PIR Sensor 

@girlie_mac PIR Sensor > Run Camera board.on('ready', function() { // Create a new `motion` hardware instance. var motion = new five.Motion(7); //a PIR is wired on pin 7 (GPIO 4) // 'calibrated' occurs once at the beginning of a session motion.on('calibrated', function() {console.log('calibrated');}); motion.on('motionstart', function() { // Motion detected // Run raspistill command to take a photo with the camera module var filename = 'photo/image_'+i+'.jpg'; var args = ['-w', '320', '-h', '240', '-o', filename, '-t', '1']; var spawn = child_process.spawn('raspistill', args); ... motion detected! Take a photo! 

@girlie_mac Processing Photo ... spawn.on('exit', function(code) { if((/jpg$/).test(filename)) { var imgPath = __dirname + '/' + filename; // Child process: read the file and detect cats with KittyDar var args = [imgPath]; var fork = child_process.fork(__dirname+'/detectCatsFromPhoto.js'); fork.send(args); // the child process is completed fork.on('message', function(base64) { if(base64) { // Send to cloud storage } }); ... var kittydar = require ('kittydar'); a cat detected! 

@girlie_mac github.com/girliemac/RPi-KittyCam 

@girlie_mac https://twit.tv/shows/new-screen-savers/episodes/19 

@girlie_mac I hacked hardware so you can too! Join meetups & events like Int’l NodeBots Day! 

@girlie_mac Thank you! @girlie_mac github.com/girliemac speakerdeck.com/girlie_mac pubnub.com github.com/pubnub