MQTT - REST Bridge using the Smart Object API
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The document discusses using the Smart Object API to create an MQTT observer that bridges MQTT topics to REST endpoints. The MQTT observer implements the MQTT abstraction layer, allowing resources to publish and subscribe to MQTT brokers. It connects REST resources to MQTT topics, repeating data updates in both directions. This enables MQTT data from devices to be accessible via REST APIs.
MQTT - REST Bridge using the Smart Object API
- 1. MQTT -‐ REST Bridge using the Smart Object API Open Source Internet of Things
- 2. SmartObject API Web Object EncapsulaBon Smart Object Web protocol interfaces, also M2M e.g. MQTT Event Model Links data with acBons Pub-‐Sub and event handlers Encapsulates local soJware components and handlers Self-‐describing data model For Resource Discovery and Linkage Sensor or other data JSON, XML, data feeds
- 3. SmartObject API – Observers • Contains graphs which define endpoints of event driven processing and communicaBon • The Observer paTern is the basis for M2M communicaBon abstracBons • Publisher, Subscriber, Event Handler classes • Reference ImplementaBon – create (POST) makes a new Observer • Publisher, Subscriber, or Handler Class – set (PUT) updates an Observer’s seZngs – get (GET) returns an Observer’s seZngs – delete (DELETE) removes an Observer
- 4. MQTT Observer • Implements the MQTT M2M AbstracBon Layer • Publish, Subscribe, or Pub+Sub using the mqTObserver resource class • Prototype opens a connecBon to a specified broker for each REST endpoint Observers.create({'resourceName': 'mqttTestObserver',! ! ! ! ! ! 'resourceClass': 'mqttObserver',! 'connection': 'smartobjectservice.com',! 'pubTopic': ’sealevel_pressure',! 'subTopic': None,! 'QoS': 0,! 'keepAlive': 60 })!
- 5. MQTT Observer MQTT Broker REST Endpoint ObservableProperty mqTObserver 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
- 6. MQTT Observer MQTT Broker REST Endpoint ObservableProperty mqTObserver PUT GET Publish from data producer Publish From REST API Publish to Other Subscribers SUB Publish to REST API Publisher Publishes REST Resource updates to the broker
- 7. MQTT Observer MQTT Broker REST Endpoint ObservableProperty mqTObserver PUT GET Publish from data producer Publish From REST API Publish to Other Subscribers SUB Publish to REST API Subscriber Makes last published data available at the REST endpoint
- 8. MQTT Observer MQTT Broker REST Endpoint ObservableProperty mqTObserver PUT GET Publish from data producer Publish From REST API Publish to Other Subscribers SUB Publish to REST API Pub+Sub Repeats data updates in both direcBons
- 9. MQTT Bridge to mulBple REST endpoints MQTT Broker REST Endpoint ObservableProperty mqTObserver PUT GET Publish from data producer Publish to Other Subscribers REST Endpoint ObservableProperty mqTObserver PUT GET
- 10. IoT Toolkit • IoT Toolkit is a reference implementaBon of the Smart Object API and related tools • REST API with real-‐Bme event model for the Internet of Things • Lightweight server that can run on small computers e.g. Raspberry Pi • Work in progress prototype (limited excepBon handling and simple interfaces)
- 11. IoT 2.0 – Interoperability M2M CoAP M2M MQ SOA M2M HTTP Smart Object API IoT Toolkit Discovery ApplicaBons Thing Models Resource Models • Object Model • REST + Event Model • M2M Abstrac<ons IoT Toolkit Connected Things, Sensors, Actuators, Data Sources Seman?c Repository • Easy to deploy new things and applicaBons using data models • Write once run anywhere, any app to any thing via any M2M • Network effect enabled • Allows for appropriate M2M choice
- 12. Interoperability Architecture SO SO SO Gateway Server Cloud Endpoints • Sensors • Devices ApplicaBon Components And Resources Databases Instances Classes SRT • Discovery • Persistence • ReplicaBon • Resource Access • Data Models • Sensor Models • Machine Models • Templates