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 ...

[Nubmian] created a rig using a pair of typical ultrasonic distance sensors ... connected to an airflow sensor. The multimeter is soon replaced by an Arduino with the help of an AD623ARZ amp.