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 ...

The human eye can only detect wavelengths in the visible light range, but a new imaging system will let us "see" infrared radiation using smartphones. When you purchase through links on our site, we ...

If you need to measure a distance, it is tempting to reach for the ubiquitous ultrasonic module like an HC-SR04. These work well, and they are reasonably easy to use. However, they aren’t without ...