[SOLVED] Controlling Linux client with MQTT (or other possibilities)

Seems like yes? Node-red can read serial input/output on a pi. You’d only be limited on your ability to program node-red to read the data.

You’ll need the “Serial” input node in node-red.

I don’t have any serial devices so I’d be useless in figuring that out. The node-red forums may be a good place to start - just have to find someone who has used one of those devices…