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 ... Here is ...

[Fernando] sent in a tip about a pet project he’s been ... the object being scanned, and an Arduino for control, but the real novelty is the way he used the sensor. [Fernando] mounted a Sharp ...

We’ve featured loads of IR Arduino projects and they are all exciting ... Maybe he will add a temperature sensor someday so it doesn’t have to run on strictly time. A more complicated problem ...