Everyone wondered how useful is the automatic brightness feature on phones, quickly adapting screen’s brightness according to the surrounding light intensity.In this project I try to create something similar for any PC or Laptop running on Linux(preferably Ubuntu 14.04).My goal was to keep it cheap and simple as much as possible.So to make a prototype of it I used LDR to measure light intensity and an arduino communicate with my machine. On my machine I used a python script to communicate over USB with arduino and to edit the file which is responsible for the brightness of screen.