Hi Sum and all,

Please explain to us exactly what kind of motor you are trying to control. I was thinking you are trying to use a "normal" DC motor and not a stepper motor. I have no experiance with stepper motors just "normal" DC or AC motors. You know, the kind with a + and - lead coming out and nothing more. If you are using a "normal" DC motor, then PWM would not seem to work for it is either 5V or 0V correct? PWM will give you a "timed" running of a motor at full speed. A DAC would give you a "range" of speed for however long you want. That is why I thought of the IR circuit to use. To "see" the RPM of the motor.

TTYL,
Dave Kaleta