IoT Toolkit and the Smart Object API Tutorial Introduction

IoT Toolkit and Smart Object API Tutorial Introduc7on

Open Source Internet of Things

IoT 2.0 – Interoperability

M2M CoAP M2M

MQ SOA

M2M HTTP

Smart Object API IoT Toolkit

Discovery

Applica7ons

Thing Models

Resource Models

•  Object Model •  REST + Event Model •  M2M Abstrac<ons

IoT Toolkit

Connected Things, Sensors, Actuators, Data Sources

Seman5c Repository

•  Easy to deploy new things and applica7ons using data models

•  Write once run anywhere, any app to any thing via any M2M

•  Network effect enabled

•  Allows for appropriate M2M choice

Interoperability Architecture

SO

SO

SO

Gateway Server Cloud Endpoints

•  Sensors •  Devices

Applica7on Components

And Resources

Databases

Instances

Classes SRT

• Discovery • Persistence • Replica7on • Resource Access

• Data Models • Sensor Models • Machine Models • Templates

IoT Toolkit

•  IoT Toolkit is a reference implementa7on of the Smart Object API and related tools

•  REST API with real-‐7me event model for the Internet of Things

•  Lightweight server that can run on small computers e.g. Raspberry Pi

•  Work in progress prototype (limited excep7on handling and simple interfaces)

Smart Object API

•  Object Model – Web Object Encapsula7on •  Data Models – Linked Data descrip7ons •  Event Model – Asynchronous M2M and applica7on soUware event handlers

•  REST API using JSON, XML, RDF representa7ons

•  Web standards and best prac7ces with new extensions

Object Model Web Object Encapsula7on

Smart Object

Web protocol interfaces, also M2M e.g. MQTT

Event Model Links data with ac7ons Pub-‐Sub and event handlers

Encapsulates local soUware components and handlers

Self-‐describing data model For Resource Discovery

and Linkage

Sensor or other data JSON, XML, data feeds

Smart Object Structure – Object Model

Smart Object

Descrip7on

ObservableProperty

ObservableProperty…

Agent

Publisher Subscriber Handler

PropertyOfInterest

Descrip7on

Observers

Handler Instance Daemon

Default Property

REST API •  Python API – Local SoUware, Agents and Handlers –  Resources (objects) are hierarchical proper7es of other resources

–  self.indoorTempValue = sensors.weather.indoor_temp.get()!

•  Web API – HYp REST Client access –  Resources are organized in hierarchical path –  GET http:my_server:8000/sensors/weather/indoor_temp!

•  Default Property –  Returns a resource associated with a higher level resource –  GET of Smart Object returns it’s Descrip7on; GET of Observable Property returns it’s Observa7on Value

API – Descrip7on (Data Model)

•  Contains graphs describing the resource data model

•  RDF in many popular representa7ons – create (POST) loads a graph into the descrip7on delete (DELETE) removes a graph or subgraph from the descrip7on

– set (PUT) updates a graph or subgraph – get (GET) returns a graph or subgraph

API – Observable Property

•  Represents sensor data or a data feed •  Can be JSON, xml, text, or other content type – create (POST): make new observable property – delete (DELETE) remove observable property – set (PUT) update Observa7on Value or data feed – get (GET) returns the current Observa7on Value

API – Observers •  Contains graphs which define endpoints of event driven processing

•  Publish, Subscribe, and Event Handler paYerns •  Reference Implementa7on – create (POST) makes a new Observer

•  Publisher, Subscriber, or Handler Class – set (PUT) updates an Observer’s seangs – get (GET) returns an Observer’s seangs – delete (DELETE) removes an observer graph

API – Agent •  Container for Event Handlers, soUware components invoked within the local context of the Smart Object

•  Observer class invokes Event Handler code •  Reference Implementa7on –  create (POST) makes a new code object instance

•  type handler or daemon –  delete (DELETE) removes code instance –  set (PUT) updates seangs of a code instance –  get (GET) returns seangs of a code instance

Weather Sensor Example

•  Weather Sensor hardware from Sparkfun •  Arduino connects hardware sensors to gateway via ethernet

•  Raspberry Pi gateway runs Smart Object API •  Arduino uses hYp POST of JSON value to update Smart Object Observable Proper7es

•  Smart Object built using python code

Weather sensor example

Sensor (Arduino)

Gateway (Rpi)

Sensor Hardware •  Wind Speed •  Wind Direc7on •  Rainfall •  Temperature •  Humidity •  Barometer

Reads sensor elements and creates sensor output values to update Smart Object in the Gateway using a simple hYp client

Gateway runs Smart Object API and exposes HTTP interface, adds descrip7onand other resources, Observers send updates to cloud server

Local Ethernet

Cloud Server acts as Gateway-‐as-‐a-‐Service for Xively Receives updates from the gateway, Observers Send periodic updates to Xively feed

Cloud Server

Internet

Client (Xively)

Internet

Xively acts as client applica7on and receives updates from the cloud service ac7ng as GaaS

Arduino Sketch PString jsonObject(objectBuffer, sizeof(objectBuffer));!! if(nextPushPoint==0) {! nextPushPoint=1;! /* use Pstring.print to format JSON string from integer */! jsonObject.println(daily_rain,1); ! /* PUT update to Smart Object server property using JSON */! client.print("PUT ");! client.print(serverPath);! client.print(”daily_rain");! client.println(" HTTP/1.1");! client.println("Content-Type: application/json");! client.print("Content-Length: ");! client.println(jsonObject.length()-2);! client.println("Connection: close");! client.println();! client.println(jsonObject);! }!

Demo Code for Weather Sensor – Smart Object and Service Crea7on

baseObject = SmartObject() # create a Smart Object to serve as the base container for other Smart Objects and resources server = SmartObjectService(baseObject) # make an instance of the service, baseObject is the object root server.start(8000) # forks a server thread to listen on port 8000 print 'hDpd started at', baseObject.Proper<es.get('hDpService’) # top level object container for sensors, class is SmartObject sensors = baseObject.create({'resourceName': 'sensors',\ 'resourceClass': 'SmartObject'}) #weather sensor Smart Object under sensors for the weather sensor weather = sensors.create({'resourceName': 'rhvWeather-‐01', \ 'resourceClass': 'SmartObject’}!

Data Model – Descrip7on for object discovery and linkage

# make a reference to the weather sensor object Descrip7on and build an example graph (could use the built-‐in reference as well) weather.descrip7on = weather.Resources.get('Descrip<on') weather.descrip7on.set((URIRef('sensors/rhvWeather-‐01/outdoor_temperature'), RDFS.Resource, Literal('sensor'))) weather.descrip7on.set((URIRef('sensors/rhvWeather-‐01/outdoor_temperature'), RDF.type, Literal('temperature'))) weather.descrip7on.set((URIRef('sensors/rhvWeather-‐01/outdoor_humidity'), RDFS.Resource, Literal('sensor'))) weather.descrip7on.set((URIRef('sensors/rhvWeather-‐01/outdoor_humidity'), RDF.type, Literal('humidity'))) weather.descrip7on.set((URIRef('sensors/rhvWeather-‐01/sealevel_pressure'), RDFS.Resource, Literal('sensor'))) weather.descrip7on.set((URIRef('sensors/rhvWeather-‐01/sealevel_pressure'), RDF.type, Literal('pressure')))!

Encapsula7on: Observable Property, Observer, and Subscriber

sealevel_pressure = weather.create({'resourceName': 'sealevel_pressure',\ 'resourceClass': 'ObservableProperty'}) sealevel_pressure.Observers.create({'resourceName':'demoServiceObserver',\ 'resourceClass': 'hDpPublisher',\ 'targetURI': 'hDp://smartobjectservice.com:

8000/sensors/rhvWeather-‐01/sealevel_pressure'}) # make a named subscriber resource outdoor_humidity.Observers.create({'resourceName': 'humiditySubscriber',\ 'resourceClass': 'hDpSubscriber',\ 'observerURI': 'hDp://localhost:8000/sensors/rhvWeather-‐01/

indoor_humidity', \ 'observerName': 'humiditySubObserver' })

Event Model – Xively Publisher -‐ Observer

sealevel_pressure.Observers.create({'resourceName': 'xivelyObserver',\ 'resourceClass': 'xivelyPublisher',\ 'apiBase': 'hDps://api.xively.com/v2/feeds',\ 'feedID': '2141862995',\ 'streamID': 'sealevel_pressure’,\

'apiKey’:'QYourApiKeyGoesHEresjhgrjgo56',\ 'updateInterval': pushInterval })

Event Model – Handler and Callback No7fier

#addHandler class adds 2 proper7es values together and stores in a third weather.Agent.create({'resourceName': 'addHandler',\ 'resourceClass': 'addHandler',\ 'addendLink1':'sensors/rhvWeather-‐01/indoor_temperature', \ 'addendLink2': 'sensors/rhvWeather-‐01/indoor_temperature', \ 'sumOutLink': 'sensors/rhvWeather-‐01/outdoor_humidity'}) # now create a callback observer endpoint indoor_temperature.Observers.create({'resourceName': 'callbackTempObserver',\ 'resourceClass': 'callbackNo<fier',\ 'handlerURI': 'callback:///sensors/rhvWeather-‐01/Agent/

addHandler'})

IoT Toolkit Project •  Smart Object API is nominally complete and stable

•  Development priori7es – Web UI for debug and demo, simple applica7ons

•  Navigator, Dashboard, Analy7cs, Graphs and Charts – M2M Endpoints for CoAP, MQTT, and others –  Test code for API –  Internal features development

•  Build SmartObject Instances from Resource Models •  Object Persistence •  Data persistence and storage

MQTT Observer •  Publish, Subscribe, or Pub+Sub using the mqYObserver resource class

•  Prototype opens a connec7on to a specified broker for each endpoint

Observers.create({'resourceName': 'mqttTestObserver',\!

! ! ! ! ! 'resourceClass': 'mqttObserver',\! 'connection': 'smartobjectservice.com',\! 'pubTopic': ’sealevel_pressure',\! 'subTopic': None,\! 'QoS': 0,\! 'keepAlive': 60 })!

MQTT Observer

MQTT Broker

REST Endpoint ObservableProperty

mqYObserver

PUT GET

Publish from data producer

Publish From REST API

Publish to Other Subscribers

SUB Publish to REST API

Connects REST Resource to MQTT Topic Publish and Subscribe

MQTT Observer

MQTT Broker


mqYObserver

PUT GET





Publisher Publishes REST Resource updates to the broker

MQTT Observer

MQTT Broker


mqYObserver

PUT GET





Subscriber Makes last published data available at the REST endpoint

MQTT Observer

MQTT Broker


mqYObserver

PUT GET





Pub+Sub Repeats data updates in both direc7ons

MQTT Bridge to mul7ple REST endpoints

MQTT Broker


mqYObserver

PUT GET




mqYObserver

PUT GET