I recently had to build an infrared close proximity sensor that could tell if something was dropped in a parcel delivery drop box. After some searching, I ended up using a microcontroller and a piece ...

How can you detect the presence of a flame without a fancy commercial device? In this post I will describe how to build cheap flame sensors at home with a couple of methods. Second Method: Secondly, ...

Some readers may recall building a line-following robot during their school days. Involving some IR LEDs, perhaps a bit of LEGO, and plenty of trial-and-error, it was fun on a tiny scale. Now imagine ...