[Klaus] wanted some sort of aid for parking his car, and after running across a $4 ultrasonic sensor, decided to build his own speaking distance sensor (.de, Google Translation). Inside [Klaus]’ ...

A low-cost (~$100), do-it-yourself (DIY) ultrasonic water level sensor/datalogger has been designed, constructed, and tested for use in education, citizen/community science, and research settings. The ...

Proximity sensors that use ultrasonic sound waves calculate distance to an object using the time it takes to receive the echo from an ultrasonic burst. But, similar bursts from other sensors in close ...

Inductive sensors are non-contact proximity sensors that detect ferrous targets, ideally ones made of mild steel thicker than one millimeter. They consist of four major components: a ferrite core with ...

Sometimes, it’s time to shut down the oscilloscope, and break out the cardboard and paints. If you’re wondering what for, well, here’s a reminder of an Instructable from [CrazyScience], that brings us ...