transformationPattern of MQTT-Channel is ignored

Setup, Configuration and Use Beginners
1
  • Platform information:
    • Hardware: Raspi 4, ConBee II
    • OS: Raspbian
    • Java Runtime Environment: openjdk11
    • openHAB version: openHAB 3.0.2 Release Build

Hey there,
I use the MQTT-Binding together with zigbee2mqtt (which shouldn’t matter, just for completion) and a mosquitto broker.

First I created a MQTT Broker Thing and set up the connection.
To then add a device I configured a Generic MQTT Thing, and add a channel (as well as an Item to hold the value):

UID: mqtt:topic:8e28935d28:e00b881b84
label: TRADFRI Remote Control
thingTypeUID: mqtt:topic
configuration: {}
bridgeUID: mqtt:broker:8e28935d28
channels:
  - id: zGfEOsP7J6
    channelTypeUID: mqtt:string
    label: Action
    description: ""
    configuration:
      stateTopic: zigbee2mqtt/0x588e81fffe032c3c

I now can receive the payload of the added device (a remote control):

{
  "action": "toggle",
  "battery": 87,
  "linkquality": 255,
  "update": {
    "state": "idle"
  },
  "update_available": false
}

However, if I try to use the transformationPattern property, it doesn’t work.
I try to set transformationPattern: JSONPATH:$.action but it is just ignored and the Item just holds the entire payload instead of just the value of action.

best regards gkhaos

2

What do the logs say? Have you installed the JSONPATH Transformation Service within openHAB?

If you do, please show your Thing and Item configuration.

2 Likes
3

Have a look here and compare if your setup is the same (I posted some screenshot of one of my items using JSON).
As well, did you install JSONPATH transformation?

4

Sorry for the late reply, but yes, the problem was the absence of the JSONPATH Transformation Service. Thanks alot :slight_smile: