@Gerrard said in Consolidating supply and GND for hotend:
Can I run 2 laser filament sensors from the 3.3V and GND of one pin (say E0), then use the input (E0/1 STOP) pins from E0 and E1.
Yes the filament monitors can both be powered from the same 3.3V and ground connection
Then, can I run a 12V and GND from the Power In terminal to the hot end to power the fans and LEDs, and run the Fan's PWM signal pin to the FAN0- and FAN1- pins?
Assuming you are using 12Vs to supply the whole system then you can use a single source of 12V, and switch the -'Ve sides (i.e use the FAN0- and FAN 1- for the two fan 've connections, possibly use fan 2- to control the LEDs.
caveats
You need to ensure you don't exceed the limits of the fan mosfets (1.5A max) There is a potential failure mode where the VIN voltage shorts onto 3.3V. this is more likely if you bundle all the wires up into the same bundle. You mention you are using a ribbon cable. This can be a good solution but be careful to manage the strain relief and flexing to it does not break and short. Also check the max current rating of each of the conductors in the ribbon cable (probably 1A max or less). If you end up putting 12V and the return GND over multiple conductors then if one breaks, the other ones will end up carrying more than they are rated for, and get hot.
