This is a quick portable circuit used to test stepper motors. It is based on small PIC 12f675 microcontroller. The pulse speed is changed with potentiometer. It allows smoothly variate between 20Hz and 3kHz.
It has couple jumper bridges to select enable and dir pins. Servo tester is powered with four NiMh rechargeable batteries that give total 4.8V. This circuit can also be used as general purpose pulse generator if needed.
