In general, nothing has functionally changed between OH2 and OH3 when it comes to MQTT, except now you need to have an external MQTT broker installed as the internal broker present in OH2 was removed in OH3.
I don’t think anything has been advertised which suggests OH3 is ‘better’ than OH2 when it comes to MQTT?
Your OP problem comes as a result of configuration of Mosquitto itself, which has nothing to do with openHAB. They recently made some breaking changes which have been linked in this thread. Unfortunately in this space there’s a lot of things to try and keep track of!
Unfortunately this is my first step in OH3.
I was waiting to update from 2.5 cause I thought “give them some time …” Was I wrong?
Basically I agree to what you are writing, but I am a Enthusiast and want to use a SmartHome
solution what offers me an easy access to a really important functionality like MQTT.
To make the MQTT story short
Somehow you need to figure out that you have to install Mosquitto not in mainUI but openhabian-config.
Then back in settings you have to install the broker, but which one?
After that you manually have to edit the mosquitto.conf, is it running now, No it still isn´t…
You know what I mean? Again I don´t want to moan, I am an Enthusiast and still enjoying OH
Just a note on this: you’re not installing a broker in this step - you’re setting up a bridge from OH3 to your external MQTT broker so that the two can talk to each other.
And as @rossko57 says, install the one which does not have System in the name.
See this post for the basics, written before the change to Mosquitto v2 on vanilla Raspberry Pi OS (not openhabian):
I am now trying to catch the tasmotas (all in setoption19 1), they don´t appear.
Maybe I better do a restart first after I installed the transformations now
I configuration manually so have never used auto discovery, but make sure you have the correct transformations installed in openHAB. From the documentation:
The HomeAssistant MQTT requires two transformations to be installed:
JINJA-Transformations
JSONPath-Transformations
These can be installed under Settings->Addons->Transformations
Here’s a post you may have come across when searching the forum:
Exactly what I have done but these homeassistant items are not coming up yet
When I press “SCAN” in order to identify devices
I can see in the log an error by the broker, but the broker is ONLINE
Yes in the UI, first I used localhost what worked to get it ONLINE, after that I have added “listener 1883” in mosquitto.conf, and changed localhost to the real IP (no :s here) still ONLINE.
But I cannot leave the IP field empty in the UI, it is required
Note that ONLINE in OH doesn’t mean it’s successfully communicating with the MQTT broker, or that the MQTT broker is actually online. It merely means (simplistically) that the configuration of your Bridge has passed some internal testing.
This is somehow disappointing
In my config there is no :s doesn´t matter
I deleted the binding, the bridge and
reinstalled mosquitto
reinstalled the binding
reinstalled the bridge
