A micro-controller based system is to be developed that will monitor the switching on and off of light in a building, storing the time that they are turned on and odd in RAM memory. This is the learn mode. There are four opto couplers connected to an input port of the micro-controller that monitors the lights. In our program we can use switches to act as these opto-couplers. When switched to run mode the system will switch the lights on and off in accordance to the stored so as to give the impression – to a potential intruder that the building is occupied. The time of day is to be kept using one of the microcontroller timer and an appropriate software program that keeps time to the nearest second. In additom to this, when the system is in the Run Mode, the system can monitor four intruder sensors-in our case these can be simulated using switches. If a switch is operated-simulating a sensor operation due to an intruder, an alarm and alarm indicator must be turned on. The alarm must be turned off after ten seconds (in a real alarm system the alarm would be turned off after 20 minutes)
