MQTT Binding issue isuue with OH2.4.0 architecture


I am trying to bind MQTT topics through openhab paper UI. I have scenario where I want my slider to pull the current threshhold from MQTT topic and and send back the command with updated value depending the current slider poisition.

I have exactly followed the steps suggested in in the link below and also getting the subscribed message as expected.

Interestingly, when Go to top Control section in Paper UI, I can see all the value is being subscribe successfully from respective topics but when I try to move the slider, I can see only 0 ( zero) is getting published.

Same is the case with Switch control. I am getting 0 in place of 1 (ON ,0 (OFF).
Here is output:

**received MQTT message, topic: RF24SN/out/2/6 value: 0**
**received MQTT message, topic: RF24SN/out/2/5 value: 0**

RF24SN/out/2/5 : Topic for switch
RF24SN/out/2/6 : Topic for slider

Please find below the line from items file

Dimmer Adjust_Lamp_Threshold "Lamp Threshold[%d %%]" <slider> {mqtt="<[broker:RF24SN/in/2/6:state:*:default], >[broker:RF24SN/out/2/6:command:*:default]"} 

Switch Switch_Humidity {mqtt=">[broker:RF24SN/out/2/5:command:ON:1],>[broker:RF24SN/out/2/5:command:OFF:0]"}

Here is the screenshot of configure channel

Can anyone suggest where I am going wrong?

Your setup of both items is using the version 1 syntax, you need to use the “channel”-syntax! The correct setting for each channel can be copied from PaperUI!
For the correct syntax to setup the dimmer read Here

Thanks for the quick response. I tried both the options but it didn’t work. I was reading some article- it seems there are issues with OH2.4.0 around MQTT 2.x architecture and it is expected to get fixed in 2.5 release.

Having said that is there any workaround ( e.,g writing a rule) to publish slider or switch date back to topics?

Appreciate your help!!

I’m running 2.4 ATM ( minus a dimmer) and it is working. There are (known) issues, but in most cases you can get it running!
Do the setup and then restart openHAB does help in my cases.

As the maintainer of the MQTT binding I strongly recommend OH 2.5m1 at least or wait another week or so for OH 2.5m2.

Is it possible to run 2.5m1 binding on release 2.4.0?
And if so which modules to drop to addons:

Thanks !

So are you essentially suggesting to reinstall OH2.4 or uninstall MQTT 2.4 from paper UI and reinstall it again ? Also, will it solve my fundamental problem related to command since in my case all topics are subscribing well with ‘state’

e,g in case of switch both inbound and out MQTT message will be command type

Switch Switch_Humidity {mqtt=">[broker:RF24SN/out/2/5:command:ON:1],>[broker:RF24SN/out/2/5:command:OFF:0]"}

Thanks David,

I will prefer to wait but do you have any documentation specific to OH 2.5m2. that I can pre-read. Right now the only documentation that I have is

I did say 2.4 works for me because you were on 2.4. If you moved somewhere else I’d follow David suggestion.
The two topics you show above are both commands to the device, in the version 2 both would be setup with the comandTopic and if necessary with the above mentioned On/Open value or Off/Closed value.