Stepper motor can be termed as digital motor because it operates on pulses. Unlike AC or DC motor that rotates continuously, stepper motor rotates in steps. It rotates in number of steps as per applied number of pulses. The common terminal is connected to –Ve (Gnd) terminal.So as we apply this four steps sequence continuously, the motor will rotate clockwise or anticlockwise. Now to change the speed of motor we have to change pulse repetition frequency (PRF) that is the frequency of applied pulses. If PRF is increased the pulse duration decreases and speed increases and vice versa.  So this project demonstrates how to vary the speed and change the direction of given stepper motor using AVR microcontroller ATmega32