I am playing around to connect to thingspeak via mqtt using the mqtt node.
Initially I send a payload with the appropriate topic in the inject node:
That did not work...
However, when I added the topic in the mqtt node's properties and just send the payload without the topic, then it works :
I would have thought that the topic would be passed on from the inject node to the mqtt node correctly in the first instance. On inspecting the debug node, the topic is passed on with "". Can some enlighten me on the difference and why?