Hi all I need help with creating school automatic. I need to connect LDR to automatic control school lights and I need to connect P.I.R and ultrasonic motion for security. I just wanna know are it is posibble to make it with one Arduino Mega. If it can be created so please send a blue print how everything I must connect because I am just 15 years old and I am not a pro on this :) Thanks for help.
You can do this using an Arduino. Actually you do not need the Mega for this simple task, a normal Arduino is more than sufficient. You do need a relay (or a relay shield) to switch the light. There is plenty of online tutorials on how to connect all of the sensors you mention, just google it.
Welcome the forum VytautasMil.
..I need to connect LDR to automatic control school lights
You do need a relay (or a relay shield) to switch the light.
Controlling lights, means access to high voltage mains circuitry. This is something that should only be done by a qualified electrician and certainly not by a 15 year old.
I suggest you stick only to the rest of the project goals , PIR sensors and motion detectors.