While PIR sensors can be used with Arduino and other microcontroller boards, those best-suited for hobby use are smart enough to perform simple tasks without any programming.

Where the original Theremin sensed hand proximity using two antenna-like capacitive sensors to control note frequency and volume, this design relies on two optical sensors to do the same job.

[mircemk] shows how to create a simple non-contact proximity sensor using little more than an Arduino Nano board, and a convenient software library intended to measure the value of capacitors. The ...

Optical sensor setup Below is the electrical wiring diagram of the optical sensor portion of the speed trap. The given setup calls for Pins A1, A2, and D3 of Arduino Uno, apart from the 5-V and GND ...