The experiment is for switching an acoustic sounder as a rain alarm after a predetermine time. It may, however, be tinkered for a number of other applications. Needless to say, this is a simple ...

[Andy] demonstrates building an ultrasonic anemometer using a cheap after-market parking distance sensor kit and an Arduino. Demo video after the break.

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 ...