“STEPPER MOTOR INTERFACE” USING 8085 MICROPROCESSOR

AIM:

The aim of the project is to demonstrate the forward/reverse stepped motions of a stepper motor, using 8085

microprocessor.

PROJECT DESCRIPTION:

The stepper motors have immense applications in printing, Industrial Robotics, Precision tool motions in drilling,

cutting and shaping machines, lathe etc.

This project is proposed to demonstrate interfacing of stepper motor to 8085 microprocessor and to run it in

continuous or stepped motion in forward or reverse direction under program control, using 8085 microprocessor.

HARDWARE DESCRIPTION:

The hardware setup consists of a microprocessor motherboard and stepper motor interface board. The motherboard

consists of 8085 MPU, 8KB EPROM, 8KB RAM, Keyboard and display controller 8279, 21-key Hex-keypad and six numbers

of seven segment LEDs and Bus Expansion connector. The stepper motor interface consists of driver transistors for stepper

motor windings and address decoding circuit. The microprocessor output the binary sequence through data bus, which are

converted to current pulses by the driver transistors and used to drive stepper motor. The software for the system is developed

in 8085 assembly language.

Fig1. Block diagram of stepper motor interface

EPROM8KB

8085CPU

LATCH

50 P

in E

xpan

sion

Con

nect

or

System bus

RAM8KB

8279KeyboardDisplay

D0-

D7

A0-

A7

Keyboard

AD0-AD7

Address/Control

Address/Decoder

Latches

Buffer

LED indication for output binary sequence

D0-D3

Con

nect

or

M

Stepper driver

Transistor driver

Display

CS

C D E F int

8 9 A B Go

4 5 6 7 Nxt

0 1 2 3 Sub