The aim of this project is to make some light on whenever a user enters toi a room and make the light off when a person
When a person enters a room a sensor detect that and make the light off. Now at the second moment when another user enters to the same room then the microcontroller first check whether lights are on or not,if lights are on then it will do nothing .So the best thing is to add some counter so that when counter is zero that means no person in the room so make the light off.
So that when a person enters the room then make the count increased by one and when a person leaves the room make the count one minus.
Now the problem with this design is that if two persons enters in the room just side by side at the same time then the counter will count 1 though it is two. So at present persons in the room is 2 ,but the counter knows the number is 1.So when ever one of the person leaves the room then counter count reaches to 0 and the lights are set off .So that should not be ,as a person is still there in the room.
Now during the implementation of this system this must be taken care off that there must not be too much space available for the entry of 2 persons i.e the room door must be so designed so that not more than 1 person be able to enter to that room.
So now what are the things are required to make the person detector.
The best way and general way to that is to use IR transmitter s as well as IR receivers.
So an IR Transceiver has to be made for that.
Then a microcontroller is used to for counting and used for deciding the fact that whether send the light signal on/off .
Now to implement the LIGHT on/OFF part we need AC relay. So when ever microcontroller give proper signal then relay activated and the light goes on or OFF based upon the output.
Next what are the possible knowledge you can have after you complete this project.
For example visitor counter , This visitor counter may be required in many places to count the number of visitors present in a hall or room etc.
Another thing that you will learn how to activate or deactivate some AC devices using a microcontroller. his may help in making some room heater on/OFF.
Next you will learn the idea of microcontroller and how to write code for microcontroller as well as how to use 8051.You can implement this using 89c51/89c52 chips.
Other required parts(Majore part) are IR light ,NE 555, TSOP, a disply usint(LCD or seven segment-for visitor count etc).