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 ...

Recently, I exhausted my stock of common passive infrared (PIR) motion sensor modules and was looking for a new one to play with. I searched the web for a small type with self-contained electronics.

Arriving home to a dark house with an armful of anything is usually an exercise in fumbling confusion until someone manages to turn on a light. [Pavel Gesyuk] has circumvented this problem entirely by ...