Quote Originally Posted by 51dueller View Post
I'm still in the preliminary stages of building a test circuit. I know I could use a L293D to drive it but it won't have the resolution as this setup. The L293D can only handle up to a 5 khz signal where as the circuit above can go 31.2 khz. The ECCP of the pic16f684 using pwm can microstep the motor providing an extremely smooth and accurate rotation. Microstepping the motors I have will rotate 0.083 degrees a step.

If you know of a single chip driver that can equal the resolution of the above circuit, I'm very much interested.
Hi, 51

a quick calculation will show with a 250 mm dia Gauge ( BIG Truck ...eh ! ), a half degree resolution is enough !!!

that is half the needle width ...

AND that is your motor FULL STEP resolution ... BTW.

so, 1/4 or 1/8 Microstepping will widely fit ... see Allegro 3967 driver, All in one ...

But you do it your way, of course !

Alain