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. ... (Arduino Uno/Nano Sketch)… [code] ...

A must-have peripheral for games consoles of the 1980s and 1990s was the light gun. A lens and photo cell mounted in a gun-like plastic case, the console could calculate where on the screen it was … ...

We love the concept of using an LCD screen to transfer data. The most wide-spread and successful method we know of is the combination of a QR code and the camera on a smart phone. But for less powe… ...