[SOLVED] OpenHAB2 using MQTT Binding - receiving a published string on a subscribed topic

[rlkoshak (Rich Koshak)]

@GreenaGiant

Am I right in assuming the only way to configure the RF is to do it the old fashioned way using the config files?

Not at all. This can be done using PaperUI. But I think we need more information.

First of all, that Channel you created on the MQTT Broker Thing cannot be linked to an Item. Instead it can be used to directly trigger a Rule. So your Rule will be triggered for ALL messages published to that topic, not just the one RfKey. Your rule doesn’t make clear whether you understand that or not.

@GreenaGiant

I tried writing a rule (I have others working fine on Things/Items that were auto discovered), which does fire, but the “receivedEvent” is always coming through as null:

Hmmmm. There might be a bug here. Did you define a separator character on the Channel?

I can confirm that that works.

Are you certain that receivedEvent is always null or is it the JSONPATH transformation that is returning null? Add logging to verify.

I would expect the JSONPATH to be $.RfReceived.RfKey (notice the dot between $ and Rf).

@GreenaGiant

Ideally I’d love to configure the payload condition in the MQTT Binding Channel to only fire if RfKey == 1 but I think you can only put values to compare against, and not a JSON parse? Then I could have a channel for each of the 16 keys.

You can and I would argue should do this, but you will need to manually create a Generic MQTT Thing and separate Channels for each RfKey. Then use MQTT 2.5 M1+ How to implement the equivalent to MQTT1 REGEX filters so the Channel only processes the messages for one of the relays. Then you can link ordinary Switch Items to the individual Channels.