Short version of Coding Mojo talk for Oslo Node.js meetup.

1. Building a Node.js Powered Robot
@markawest

5. “Any application that can be
written in JavaScript, will
eventually be written in
JavaScript”
James Atwood (founder, stackoverflow.com)

8. NodeBot Rover

9. NodeBot Rover Demo
https://vimeo.com/162426456

10. Putting the Hardware Together

11. The Arduino Ecosystem
• MicroControllerplatform.
• Many different Arduino
models.
• Open Source design.
• Extensible via “Shields”.

15. Two Servos
for Camera
Pan & Tilt
Servos wired
to Arduino
Chassis
Raspberry PI
In Plastic Case
WIFI Dongle

16. Raspberry PI
Camera
Wired directly
to the
Raspberry PI

17. Actuators
Sensors
Nervous System
Raspberry PI 2Raspberry PI Cam
Arduberry Microcontroller Arduino Chassis Servo
Servo
Brain
NodeBot Rover Hardware

18. Actuators
Sensors
Nervous System
Raspberry PI 2Raspberry PI Cam
Arduberry Microcontroller Arduino Chassis Servo
Servo
Brain
NodeBot Rover Hardware

19. Controlling the Hardware

20. Raspberry PI 2
Arduberry
Servo
Software Communication across
Hardware Layers
Servo
Raspberry PI Chassis
JavaScriptPI Binary (Compiled C / C++)

21. The NodeBots Movement
Source : nodebots.io

23. 1. Maturity
2. Community
3. DSL
4. Portability
5. Open Source
6. Node.js ecosystem
7. REPL
Benefits of using Johnny-Five

24. Imports J5 Dependancy
Adds LED instance to REPL
Declares LED as connected to UNO Pin 13
Blinks LED every 500 milliseconds
Code block triggered by UNO ”Ready” Event
Initialises UNO
Johnny-Five Code Example
var five = require("johnny-five");
var myBoard = new five.Board();
myBoard.on("ready", function() {
var myLed = new five.Led(13);
myLed.blink(500);
this.repl.inject({
replLed: myLed
});
});

25. Johnny-Five REPL Demo
https://vimeo.com/134953425

26. Arduberry
Servo
Bridging the gap with Firmata
Servo
Raspberry PI Chassis
Johnny-Five
(Firmata Client)
Std. Firmata
(Firmata Server)
JavaScriptPI Binary (Compiled C / C++)

27. Getting Started with Johnny-Five
1. Buy an Arduino Experimenters Kit.
2. Follow the tutorials at http://node-ardx.org.
3. Visit http://johnny-five.io for more
information and inspiration.

28. Using MQTT to Glue the
Components Together

29. Johnny-Five
Process
Express
Process
Raspberry PI 2
WE
Browser
HTTPS
NodeBot
Rover
Hardware
Firmata

30. Johnny-Five
Process
Express
Process
Raspberry PI 2
WE
Browser
HTTPS
NodeBot
Rover
Hardware
Firmata
MQTT
Message Broker
MQTT
MQTT over
WebSockets
Commands
Acknowledgements
MQTT.js
Client
MQTT.js
Client

31. Why Add a Message Broker?
• Seperation of
concerns.
• Isolate main
components for
easier testing.

32. MQTT – MQ Telemetry Transport
• Internet of Things connectivityprotocol.
• Designed to be lightweightwith a small footprint and little
overhead.
• Requires a Message Broker (publish/ subscribe).
• Used by Facebook for pushing updates to mobile clients.

33. Adding MQTT to the NodeBot Rover
Broker
• Public MQTT Broker
– ManyPublic Brokers exist.
– One less process to run on
RaspberryPI.
Client
• MQTT.js
– Provides an MQTT client
libraryfor Node.js.
– Extremelysimple to use.
– Integrates seamlesslywith
Johnny-Five.

34. MQTT.js (Node.js) Client Example

35. MQTT Over WebSockets with MQTT.js
• MQTT.js is a Node.js package and is
meant for use on the Server Side.
• To allow MQTT.js to run from the
Browser, we first needed to
”Browserify” the MQTT library.
• We could then access the
”Browserified” MQTT client library
from the Browser.
• This solution requires that your MQTT
Broker has a WebSocket endpoint.

36. HTML5 Speech Recognition
(not Node.js, but nice to know)

39. Speech Demo
https://vimeo.com/168245807

40. More about HTML5 Speech
Recognition
https://utbrudd.bouvet.no/2014/11/11/getting-
started-with-html5-speech-recognition-on-
google-chrome