With a standard old HC-SR04 ultrasonic sensor, an audio module and a servo ... sound like for anyone who has a bunch of these little Arduino-compatible modules lying around and has probably ...

To that end, it uses an Arduino Nano armed with an ultrasonic distance sensor to detect when mice have entered a plastic container. The container’s hinged door is is held open with a servo.

All you generally need is the Arduino IDE, which already includes most of the popular libraries for interfacing with frequently used components like ultrasonic sensors and LCD modules. The ...