e-Hobbyist

A bit delayed post. :D Apologies...               Recently I received a few boards and accessories which was ordered previously through Ali Express. Don't mind if I say that AliExpress is one of the best marketing services for small electronics components. So, one among the boards was a PIR Relay Module which costs around ₹180 for me. In my house, I and my brother are the laziest and we don't use to turn off the lights once we leave the room. I wished I could install the board to the existing switch so as to make the lights automatic.                   Coming to the working principle of PIR Sensor, it usually consists of two special materials (Pyroelectric) which are sensitive to Infrared waves. When no change or motion occurs both the materials since the same amount of IR and stays idle. But as soon as there is a motion of a human or any changes which produces a difference in heat, the two material s...