[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 ...

This one is an unusual smart home project, potentially - how to monitor a fish tank’s health with an AI-enabled ultrasonic sensor system. The detailed project is highlighted on Hackser.io and features ...

With a standard old HC-SR04 ultrasonic sensor, an audio module and a servo to drive a custom gauge needle he’s made a device which can warn people around you if they’re too close for comfort.