3Dprint or CNC extension board for any development board (5v or 3.3v logic level)
Further info at www.reprap.org/wiki/RDB-STPTS-002-DIY
Current TODO list:
*rework the 6.3mm fuse footprint (currently does not fit correctly)
*maybe? add led indicators for endstops driven by low Vg(th) mosfet
*maybe? add current limited vcc for endstops headers just in case