I have an MQTT broker working fine, and one of the command topics requires a publish message to /mylan/tests/identify but the payload needs to be NULL (nothing). The mere posting of a null payload to the topic channel, is sufficient to secure a response on another channel.
This works fine using mosquito and logging to the terminal, i.e. mosquito_pub -t /mylan/tests/identify -n and I can read a value on another state topic.
So, question is, how do I implement this in OH? A switch type is no good as it posts ON/OFF or 0/1 etc. The publish must send a null payload otherwise the MQTT client will throw an exception.
Please note that this isnt my design, it is what I must work with, a company retailer, so please accept the poor design and provide a constructive solution - thank you. (yes yes yes, I know it isnt “right” !!!)