I recently had to build an infrared close proximity sensor that could tell if something was dropped in a parcel delivery drop box. ... Here is the diagram of my Arduino infrared close proximity sensor ...

The part list consists of one Arduino, two resistors, and one IR emitter. That’s right, an emitter. When an LED (IR or otherwise) is reverse biased it can act as a light sensor.

We’d seen it done with buttons, switches, gestures, capacitive touch, and IR remote, but never like this. [electron_plumber] made an LED that can be blown out like a candle, and amazingly it … ...

I think that we can use the type TSOP1838/AH1838/VS1838 infrared receiver module here. It’s noteworthy that the temperature sensor socket’s pin assignment is in the correct order for DS18B20 only.

The sensor is intended as an alternative to pyroelectric sensors or PIR detectors in home automation, building automation, healthcare, security and industrial applications. Typically human presence ...