This is done by relay.
Automatic room light controller with microcontroller.
If a person enters into the room the ir sensors send the signals to the microcontroller such that the door opens.
Automatic room light controller with auto door opening and closing the system depicted in the above figure comprises two pairs of ir transceivers.
This automatic room controller can be implemented by using a simple microcontroller and wireless ir technologies.
How they count the people and turn on or off the light when nobody is inside.
We often forget to switch off lights or fans when we leave a room.
Home automation with automatic room light controller.
Automatic room lighting system is a microcontroller based project that automatically turn on or off the lights in a room.
One is placed outside in front of the door and the other is placed inside the room.
Therefore an automatic room light controller automatically turns on the lights when a person enters into a room and turns off the lights when the person leaves the room.
Automatic room light controller section microcontroller turns on the room light when the person count is greater than or equal to one.
Since the relay is used you can connect an ac bulb or dc bulb as per your requirement.
Arduino based visitor counter with automatic light control often we see visitor counters at stadium mall offices class rooms etc.