I am working with @phillutz… and to give some additional background on this…
We have been trying to standardize the open-source polyjets (e.g. Plan B) to a 3d printing firmware for longer support and better integration. We originally started on Marlin but ran into issues controlling all the motors (which Klipper magically solved).
We have been able to successfully build the unit and wire the motors into the system with them running; however, my next big hurdle is getting the RepRap HP inkshield working.
Right now we have a Raspberry PI 3B+ connected to a Megatronics v3. We are looking for some direction on the appropriate response; originally I was looking to control the board from a stepper motor but that is more “hacky” than I would like to go.
We need to control the inkshield with five pins; which right now is designed for the Arduino. I will say we are looking to keep this code in the public domain and have seen A TON of people trying to get this to work but with no dice.