Bearmos designed a 3-axies CNC stepper motor controller. It has a ATX connector, allowing it to be powered from a computer power supply. The motors are driven via onboad driver chips, while commands are received from the computer Via the parallel port.
This board is mainly designed to be inexpensive, have lots of indicators for showing what’s going on (making troubleshooting a bit easier). It includes integrated driver chips (not modules that need to be purchased at $15 ea), which should also help out with heat dissipation.
The only (relatively) novel thing about this design is that it includes some circuitry to automatically reduce the current (~1/3 of “active” current) to the stepper motors after they’re inactive for a period of time (probably around 1 sec). A small PIC, an analog mux, and a resistor network are included to take care of this task.
Via the forum.