This book contains the major details of the circuit of the mother board as a hardware and the software part which avails any beginner to start a project.As a developing country power sources of India are limited. We know, a major part of our electricity is being wasted due to our incognizance. After leaving the room the fans, lights etc. remain on unnecessarily. The main object of this project is to minimize the wastage of electricity. The other objective of this project is to detect a person and will automatically switch on the light. When a person enters into the room, the load will get power and can be run by their switches. The counter circuit can count the number of persons staying in the room.