The 8051 Microcontroller and Embedded

Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

8255 HANEL
INTERFACINGStepper Motor Connection To The 8255

(cont

’) Figure 15-9. 8255 Connection to Stepper Motor

DecodingCircuitry

A2 A7

D0 D7WRRDA0A1

From 8051

ULN2003 Connection for Stepper MotorPin 8 = GNDPin 9 = +5V

8255

ULN2003

Stepper Motor

1 2 3 4

16 15 14 13

COM

COM +5V

Use a separate power supply for the motor

D0 D7 A1A0 RESETCS

PA0PA1 PA2

WRRD

PA3