Discuss Stepper motor interfaced to the 82C55.

A stepper motor rotates into steps in response to digital pulse input. There shaft of the motor rotates in equivalent increments while a train of input pulses is applied. For controlling direction, no. of steps to appropriate pulses is applied to the stator windings of the motor.

There 12 V supply is used to energize the poles. All pulses sent by the microprocessor switch on rated voltage to the windings of the needed poles. A delay subroutine is incorporated during the program. After energizing one set of pole windings some delay is given, then the power supply is switched on the other set of pole windings. That delay governs the speed of motor.

8255 connection to stepper motor