I am trying to use reprap shield for my own project which is similar to 3d printer system. My plan was using arduino mega and reprap shield for driving motors and connect arduino to raspberry pi for controlling arduino. And for that purpose I wrote a basic arduino code that gets input from serial connection for angle and drives motor according to that angle. While my serial communication is working without reprap (I can see arduino prints on monitor), when I try to connect it to reprap I am no longer able to communicate with arduino. Is it possible to use my own comminication while reprap shield is connecten to arduino?