Circuit for running a driver as a power feed?

[Greenbuggy]

Hey guys I'm looking for a circuit to run a stepper driver that takes +5V signals for pulse and direction and has a potentiometer to control speed. Ideally using parts that can be gotten from radio shack.

Searching has only dug me up threads where people argue about the tenets of CNC vs. manual control over drives. I don't wish to re-hash this issue. I want to put a control buttons on my BP when I convert it over so I can actuate the stepper drivers without using the jog features thru a CNC program as a lot of work I do is still manual (I want to watch the work on the machine without simultaneously trying to juggle my laptop), and my breakout board has not arrived yet so no hooking it up to a PC quite yet. But I'd like to test my stepper wiring and make sure that the drives and steppers work as they should.

Thanks
Kris

[marzetti]

You could do it with a 555 timer (a <$1 part at Radio Shack). You can find circuit details here: Linistepper "4 AXIS / 555 / PWR" kit