All of these projects either use minimal components, short (and easily understandable) codes, or both ... with only an Arduino UNO, ultrasonic sensor, force-sensitive resistor (or push button ...

For this setup, the program ... ultrasonic sensor on the inside of the lid for detecting the trash level. On the software side, things are just as straightforward. The code includes two Arduino ...

[Greg06] even included an ultrasonic distance sensor for the obstacle avoidance mechanism. Honestly, if it weren’t for the ultrasonic distance sensor protruding from the spherical body ...