Ultrasonics or ultrasound is a radar-like system that uses ultrasonic signals at frequencies above those typical for human hearing, usually above 16 to 20 kHz. The 40- to 70-kHz range tends to be most ...
The HC-SR04 ultrasonic range sensor is a pretty cool pre-wired module that you actually enjoy using when you start playing with electronics, microcontrollers, and robotics. As you might have noticed, ...