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 ...

[mircemk] shows how to create a simple non-contact proximity sensor using little more than an Arduino Nano board, and a convenient software library intended to measure the value of capacitors.

g. as proximity sensors. First, the sensor pattern is printed. Then, the sensors are subjected to an electric field making the piezolectric polymers align to adopt the targeted pressure sensitivity.