AI-on-the-edge-device-docs/docs/MQTT-API.md

MQTT API

The device is capable to register to a MQTT broker to publish data and subscribe to specific topics.

!!! Note Only MQTT v3.1.1 is supported.

The MQTT service has to be enabled and configured properly in the device configuration via web interface (Settings -> Configuration -> section MQTT)

The following parameters have to be defined:

• URI
• MainTopic (optional, if not set, the hostname is used)
• ClientID (optional, if not set, AIOTED- + the MAC address gets used to make sure the ID is unique)
• User (optional)
• Password (optional)
• RetainFlag (optional)

Published topics

Status

MainTopic/{status topic}, e.g. watermeter/status

• Connection

• Interval

• MAC

• IP

• Hostname

• Uptime

• FreeMem

• WifiRSSI

• CPUTemp

• Status

Result

MainTopic/{NumberName}/{result topic}, e.g. watermeter/main/value

• Value

• Raw

• Error

• JSON

• Rate

• Rate_per_time_unit

  The time Unit gets set with the Home Assistant Discovery, e.g. h or m (minutes)

• Rate_per_digitalization_round

  The interval defines when the next round gets triggered

• Changeabsolut

• Timestamp

• JSON

  All relevant results in JSON syntax

GPIO

MainTopic/{GPIO topic}, e.g. watermeter/GPIO/GPIO12

• GPIO/GPIO{PinNumber}

  Depending on device configuration (Settings --> Configuration --> section GPIO)

Subscribed topics

MainTopic/{subscribed topic}, e.g. watermeter/ctrl/flow_start

Control

• ctrl/flow_start

  Trigger a flow start by publishing to this topic

  • Payload:
    • any character, length > 0

• ctrl/set_prevalue

  Set the last valid value (previous value) to given value or the actual RAW value. Payload needs to be provided in JSON notation.

  • Payload:

    • Set to given value (value >= 0): {"numbersname": "main", "value": 12345.67890}

      • "numbersname":Provide name of number sequence, e.g. "main"
      • "value": provide the value to be set

    • Set to actual RAW value (value < 0, a valid RAW value is mandatory): {"numbersname": "main", "value": -1}

      • "numbersname": Provide name of number sequence, e.g. "main"
      • "value": Provide any negative number

• GPIO/GPIO{PinNumber}

  Depending on device configuration (Settings --> Configuration --> section GPIO)