Now we can stepped into the light with our favorite microcontroller Arduino! Since a vast number of analog/digital ambient light sensors/light sensor modules are now available at reasonable price, ...

This Circuit can compare the Light level in an area. It uses a PN Photodiode as the light sensor and IC CA3140 as voltage comparator. The circuit is ideal as the front end of burglar alarm circuits.

image: Artist's impression of an integrated light sensor circuit based on nanowire arrays (Javey Group). view more Credit: Lawrence Berkeley National Laboratory; University of California at Berkeley ...