Im looking for something to give a ttl pulse into a stepper motor driver board. I thought of using a 555 but I'm not sure on the accuracy level of this, I'd rather have something where I could set the frequency (maybe using dip-switches?) and it would be properly accurate. The frequency range would be fairly low, say a range from 1-50Hz. Any layouts that people know of for such things? Would it need to be crystal controlled for acuracy? James.