• To develop an assembly language program to control a "simulated" intelligent domestic lighting system with the intention of deterring burglary.
• To produce a schematic circuit diagram of the proposed system.
• To make use of the MPLAB environment with its simulator and appropriate stimulation file(s) to implement the software of the system.
• To investigate the modifications required in order to develop the system around an alternative microcontroller.

Introduction

The idea is to develop a program to control the electric lights in a home. According to a recent crime survey the highest percentage of homes burgled (77%) were those that were not occupied at the time. The idea behind this assignment is to develop a system that records the lighting pattern of an occupied home so that, when the home is unoccupied, the system will turn lights on and off to give the impression that the home is occupied.

The development should start by looking at the control of a single house-light. However, you should bear in mind how your program will deal with more than one light.

The system is to have two modes of operation:

• Record mode

• Playback mode

When the system is placed into record mode, it should monitor the status of the light, what time it came on, what time it was turned off, and record this data in memory.

When placed into playback, the system should turn the light on and off according to the recorded on/off pattern at the correct time.

The system will, of course, need to keep some sort of record of 'time of day'. In a practical system the light could be controlled by a triac. The system itself would be powered from the mains, via suitable circuitry.