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 ...

[Fernando] sent in a tip about a pet project he’s been working on. It’s an interesting take on a 3D scanner. He used a stepper motor to rotate the object being scanned, and an Arduino for control, but ...

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 ...