Producing items onto a screen simply by touching the air is a marvelous thing. One way to accomplish this involves four HC-SR04 ultrasonic sensor units that transmit data through an Arduino into a ...

In addition to the Arduino, you’ll need the four wheels, batteries, infrared and ultrasonic sensors, jumper wires, a DC power switch, and several motor parts.

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 ...