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 ...

Such a a useful circuit ... single-pixel infrared camera that picks up everything in a 90° cone starting at the sensor.” [MakeFunStuff] paired this easy-to-use sensor with an Arduino Nano ...

It features over 5,400 projects, ranging from simple tutorials — like using a soil moisture sensor ... Tinkercad is a free online platform you can use to build and test out your Arduino circuits.