Powered by a pair of Arduinos and using transducers salvaged from the extremely popular HC-SR04 ... the ultrasonic transducer is simply tied to one of the digital pins on the Arduino. The receiver ...

Inside [Klaus]’ device is an Arduino Uno, an HC-SR04 ultrasonic distance sensor, and an Adafruit Wave Shield. Originally, this parking/distance sensor used a small TFT to display the distance to ...