Strictly speaking, a Theremin uses a pair of antennae that act as capacitors in a specific R/C circuit. Looking at ...

The SparkFun Ultrasonic Distance Sensor - TCT40 (sen-24805) a user-friendly upgrade to the popular HC-SR04 sensor, offers non-contact distance measurement from 2cm to 400cm with an accuracy of 3mm.

Abstract: Sensors are vital tools in monitoring operating conditions and collecting data in scientific studies and engineering works. However powering sensors for a long term in harsh environments ...

Bonezegei_HCSR04 is a simple and easy-to-use Arduino library for interfacing HCSR04 ultrasonic sensor module. The library provides functions for measuring distance, setting trigger and echo pins. The ...