I have a Shim defined as a:
MQTT On/Off Sensor device
State value is in the payload fields and is a json boolean
Sensor Type is Power On/Off
Everything works, except, on each state update the plugin throws
state key onOffState not defined (ignoring update request)
Probably an if missing somewhere, because the actual device state in the State column updates properly.
And, FWIW, I had the same problem as reported by roquej, triggers would not fire. I finally deleted all MQTT devices, and the plugins, restarted Indigo, re-installed the plugins and devices,. and it started working. Odd.
BTW, thanks for the plugins, I am still trying to wrap my head around MQTT, especially returning messages back to the actual real world device. But, it looks like a pretty neat way to avoid custom plugins. At least in some cases. For example, my application is to observe, and possibly control a wireless sprinkler system from LinkTap.