@e4d If you mounted the electronics in a metal box, can you confirm that the enclosure is properly grounded (GND)? You can stop DCS on the RockPi and check via gpiotools (gpioread AFAIR) if the input signal is correctly read once you hook up that line to GND and +3.3V respectively.

I think that you can send gcode commands from the ESP32 to the Duet to execute. Via HTTP or serial connection. I guess that this allows you to send gcode such as setting global variables that your conditional code can access. Others may know more details.

@KOlasmics I'm glad you found a solution!