oddWires IoT-Bus, Documentation

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iot-bus Documentation, Release latest
adapter = new WebThingAdapter( "w25" , WiFi.localIP());
const char
*
ledTypes[] = { "OnOffSwitch" , "led" , nullptr };
ThingDevice led ( "LED" , "LED" , ledTypes);
ThingProperty ledOn ( "On" , "" , BOOLEAN, "OnOffProperty" );
These are the the lines of code that define the Mozilla-IoT Thing and its properties.
const char
*
ledTypes[] = { "OnOffSwitch" , "led" , nullptr };
This line defines an array of types ended by a null pointer. These types are @types, that is they are pre-defined types
that the Mozilla-IoT platform understands semantically. That is, what they are and how to render and interface with
them.
ThingDevice led ( "LED" , "LED" , ledTypes);
This line defines a LED named LED. Note the reference to ledTypes defining the device type or types. Officially these
are described as capabilities. You can find the current list available
here .
ThingProperty ledOn ( "on" , "" , BOOLEAN, "OnOffProperty" );
This defines a property “on” which has a property type of OnOffProperty. Again, this is a predefined property type.
Note: There is no connection between the property and the device or adapter at this point. Although there is no
mention of an adapter here, it is an adapter that connects to a gateway and exposes its capabilities.
led.addProperty( & ledOn);
adapter -> addDevice( & led);
adapter -> begin();
These three lines add the ledOn property to the led, then add the device to the adapter and then start the adapter. Once
the adapter has started it can be recognized by the gateway.
{
"@context" : "https://iot.mozilla.org/schemas/" ,
"@type" : [ "Light" , "OnOffSwitch" ],
"name" : "LED" ,
"description" : "LED" ,
"properties" : {
"on" : {
"@type" : "OnOffProperty" ,
"type" : "boolean" ,
"href" : "/things/led/properties/on"
},
This json extract illustrates What is happening under the covers. The arduino-webthing library is turning the definitions
above into JSON when it is polled by the gateway. This json describes the capabilities, properties, actions and events
that are possible with this device or devices. In theory there is no limit to what can be described in the schema.
However, in practice if you ant to control it using Mozilla-IoT it needs to be an @type that it knows how to render or
effectively fold into one of those types.
Most of the rest is boiler plate, but do note that you’ll want to take note of the ip address that is displayed on the
serial monitor once WiFi has started because you can use that ip address to get the raw json response provided by the
device once it is up and running. This is useful for debugging because you can see exactly what will be provided to
the gateway.
138 Chapter 40. LED Thing Tutorial