I have an external application (Node-RED Dashboard) with a button that triggers an MQTT event. Until OH 2.3 I used the MQTT eventbus to turn a Homematic switch on/off based by sending “ON” or “OFF” to topic “openHAB/in/HMSwitch/command”. How do I do this with the new MQTT Binding 2.4 without the MQTT Eventbus?
You will need to create an MQTT thing broker and then a generic MQTT thing with a switch channel subscribing to the topic on the state. Don’t forget to add the
isCommand parameter so that the state change will be passed as a command to the other channels for that item
And then add the channel to your item.