coding mojo : node.js meetup
TRANSCRIPT
BuildingaNode.js PoweredRobot
@markawest
“AnyapplicationthatcanbewritteninJavaScript,willeventuallybewrittenin
JavaScript”
JamesAtwood(founder, stackoverflow.com)
NodeBot Rover
NodeBot RoverDemo
https://vimeo.com/162426456
Puttingthe HardwareTogether
TheArduino Ecosystem• MicroController platform.
• ManydifferentArduinomodels.
• OpenSourcedesign.
• Extensiblevia“Shields”.
Two ServosforCameraPan&Tilt
Servos wiredtoArduinoChassis
Raspberry PIInPlastic Case
WIFIDongle
Raspberry PICamera
Wired directlytothe
Raspberry PI
Actuators
Sensors
Nervous System
RaspberryPI2RaspberryPICam
ArduberryMicrocontroller Arduino Chassis Servo
Servo
Brain
NodeBot RoverHardware
Actuators
Sensors
Nervous System
RaspberryPI2RaspberryPICam
ArduberryMicrocontroller Arduino Chassis Servo
Servo
Brain
NodeBot RoverHardware
Controllingthe Hardware
RaspberryPI2
Arduberry
Servo
SoftwareCommunicationacrossHardwareLayers
Servo
Raspberry PI Chassis
JavaScriptPI Binary (Compiled C/C++)
TheNodeBots Movement
Source:nodebots.io
1. Maturity2. Community3. DSL4. Portability5. OpenSource6. Node.js ecosystem7. REPL
BenefitsofusingJohnny-Five
ImportsJ5Dependancy
Adds LEDinstance toREPL
Declares LEDasconnected toUNOPin13
BlinksLEDevery 500milliseconds
Codeblock triggered byUNO”Ready”Event
Initialises UNO
Johnny-FiveCodeExamplevar 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
});});
Johnny-FiveREPLDemo
https://vimeo.com/134953425
Arduberry
Servo
BridgingthegapwithFirmata
Servo
Raspberry PI Chassis
Johnny-Five(Firmata Client)
Std.Firmata(Firmata Server)
JavaScriptPI Binary (Compiled C/C++)
GettingStartedwithJohnny-Five1. BuyanArduino ExperimentersKit.
2. Followthetutorialsathttp://node-ardx.org.
3. Visithttp://johnny-five.io formoreinformationandinspiration.
UsingMQTTtoGlue theComponentsTogether
Johnny-FiveProcess
ExpressProcess
Raspberry PI2
WE
Browser
HTTPS
NodeBotRover
Hardware
Firmata
Johnny-FiveProcess
ExpressProcess
Raspberry PI2
WE
Browser
HTTPS
NodeBotRover
Hardware
Firmata
MQTTMessageBroker
MQTT
MQTToverWebSockets
Commands
Acknowledgements
MQTT.jsClient
MQTT.jsClient
Why Add aMessageBroker?
• Seperation ofconcerns.
• Isolate maincomponents foreasier testing.
MQTT– MQTelemetry Transport• Internet of Thingsconnectivityprotocol.
• Designed tobelightweightwith asmall footprint andlittleoverhead.
• Requires aMessageBroker(publish /subscribe).
• UsedbyFacebook forpushing updates tomobileclients.
Adding MQTTtothe NodeBot RoverBroker
• PublicMQTTBroker
– ManyPublicBrokersexist.– Onelessprocess torunon
Raspberry PI.
Client
• MQTT.js
– Provides anMQTTclientlibrary forNode.js.
– Extremely simpletouse.– Integrates seamlesslywith
Johnny-Five.
MQTT.js (Node.js)ClientExample
MQTTOverWebSockets with MQTT.js• MQTT.js isaNode.js package andis
meant foruse on the ServerSide.
• Toallow MQTT.js torunfromtheBrowser,we firstneeded to”Browserify”the MQTTlibrary.
• We could then access the”Browserified”MQTTclient libraryfromthe Browser.
• Thissolution requires that your MQTTBrokerhasaWebSocket endpoint.
HTML5SpeechRecognition(notNode.js,but nice toknow)
SpeechDemo
https://vimeo.com/168245807
MoreaboutHTML5SpeechRecognition
https://utbrudd.bouvet.no/2014/11/11/getting-started-with-html5-speech-recognition-on-
google-chrome
