Help! DIY 4 amp L297/6203 driver

[tribbles]

The code could be pretty much as kwacker has suggested (obviously not pseudo-code though). I'd use timer interrupts.

Using two of the PIC's pins to control Vref is a neat idea - and two trimmers should be fine.. You could use a third pin with a trimmer for configuring the timeout (should be very easy to do).

[Ross77]

Exellent. This is moving along nicley now.

Good idea on the trim pot for time out, I like it...

So the only decision now is what pic to use and the pin out? It looks like im not going to use the short circuit protection so the the tripple 3 input AND gate is wasted in this circuit.

Are there enough pins on the pic to implment the 1/2 step boost, or will it make the code difficult?

Last question. dose this need a crystal or can it be linked to the sync pin on the L297 for external clock?