[mark] had an interesting idea when looking at all the wiring of a typical 3D printer; Use CAN Bus. There are a lot of wires going to the extruder assembly, and with most designs this thing is flyi… ...

Learn six best practices for wiring and grounding CAN and LIN buses with Arduino. Avoid noise, interference, and errors with shielded cables, resistors, and modules.

This is a wiring diagram that [Soranne] put together when developing a method of programming PIC microcontrollers using an Arduino board. You can see that he takes care of the 12V issue by ...