[SOLVED] Mqtt client setup on openhabian

If you have the mosquitto broker running in another pi, you don’t need to install mosquitto on the openhabian pi too.

Install the mqtt binding in the paperUI
This will create a file called mqtt.cfg located in the config/services folder
Edit this file to include the details of your already running broker and OH will connect to that broker

See:
https://www.openhab.org/addons/bindings/mqtt1/

and:

By the way, I use this set-up too, I have a mosquitto broker running alone on a pi-zero. That’s all it is running. And OH is running on a recycled HP thin client.