COAPinteraction.md

Introduction

For the CoAP interaction you browser needs to provide a user agent for the Constrained Application Protocol (CoAP). The Copper add-on provides such a user agent for the Firefox browser.

NOTE: CoAP 13- The gateway currently supports the CoAP 13 draft.

Discover available resources

According to the CoRE link format you can query the gateway using the `/.well-known/core` URL.

Request:

COAP GET coap://localhost/.well-known/core

Response (Excerpt):

</watchService>;rt="obix:WatchService";if="obix"
</alarms>;rt="obix:AlarmSubject";if="obix"
</VirtualDevices/virtualPresence>;rt="iot:PresenceDetectorSensor";if="obix"
</VirtualDevices/virtualPresence/presenceStatus>;rt="obix:bool";if="obix"
</VirtualDevices/virtualBrightnessActuator>;rt="iot:BrightnessActuator";if="obix"
</VirtualDevices/virtualBrightnessActuator/value>;rt="obix:obj";if="obix"
</VirtualDevices/virtualBrightnessActuator/value/history>;rt="obix:int";if="obix"
</VirtualDevices/virtualBrightnessActuator/value/history/count>;rt="obix:int";if="obix"
</VirtualDevices/virtualBrightnessActuator/value/history/start>;rt="obix:abstime";if="obix"
</VirtualDevices/virtualBrightnessActuator/value/history/end>;rt="obix:abstime";if="obix"

Query or modify a sensor or actuator

Use the same oBIX interaction like with HTTP.

Be sure to select coap13 - selection button in upper right of Copper

Observe a resource using CoAP

One big advantage of CoAP is the support for asynchronous communication. Use the OBSERVE protocol verb to subscribe to a resource, like a temperature sensor or brightness actuator.

Request:

COAP OBSERVE coap://localhost/VirtualDevices/virtualBrightnessActuator/value

Issue some PUT requests in parallel, e.g. using a HTTP client.

Be sure to select coap13 - selection button in upper right of Copper