MC68HC11A8-Runway Lights

This project is based on Microcontroller M68HC11A8. The Runway Lights project give a miniaturized representation of a runway lighting system, in airports for secure landing of night flights. This helps the pilot to locate and align to the direction of runway.

To represent such a system, LED is used as light source. They are driven through transistorized circuit for current stability. Since the transistor is inverting, we have to supply a binary 0 to turn LED on. The program loads required value to accumulator A and copies it to Port B. For example, to glow two LED at bottom most row, place 0x7E at Port B (refer program at label L1).

The circuit can be modified for better usage by replacing given transistors by power transistors and high power relays or TRIAC instead of LED. The relays or TRIAC can be used to drive high intensity halogen bulbs as in real system. A real Runway Light system may require more number of lights instead of eight LED shown here.

The source code written either in C or Assembly language can be viewed from the code editor window.

The program is as shown:

LDX   #0X1000

LDAA   #0XFF

STAA   0X1004

L1: LDAA   #0X7E

STAA   0X1004

LDAA   #0X3C

STAA   0X1004

LDAA   #0X18

STAA   0X1004

LDAA   #0X00

STAA   0X1004

LDAA   #0X81

STAA   4,X

LDAA   #0XC3

STAA   4,X

LDAA   #0XE7

STAA   4,X

BRA   L1

The source code in the code editor window has to be compiled  after making any modifications

(editing). Also the code can be debugged during simulation.