MQTT Protocol

The communication protocol used to send data between the smart device and the AWS broker.

Broker Namespace Topics

The MQTT protocal uses a form of addressing called MQTT Topics to allow MQTT clients to share information. These topics are structured as a hierarchy, similair to a file directory or web endpoints, with the forward slash ( / ) as the delimiter.

All communication between the buoy devices (MQTT client) and the AWS broker will follow the following conventions for topic hierarchy.

$aws/<version#>/<buoy_id>/<specific_endpoint>

The MQTT topics are case-sensitive, so convention is that all topics are lower-case.

A diagram of the broker namespace topics can be found below:

The interactions between the Buoy Device (MQTT client) and the Dashboard (MQTT client) can be seen through the publish and subscription links.

MQTT Packet Payload

All MQTT message payloads will be in JSON form. The specific structure, key-value pairs, for these payloads can be found in the relevant subsections for the different message types.