For-fun experiment with an Arduino UNO, where a passive piezo-buzzer’s pitch is controlled by an ultrasonic sensor (HC-SR04). The whole idea of this “pseudo-theremin” is to obtain the proximity to the ...

Basic motion sensing setup using Arduino, PIR sensor, LEDs, and push button for interaction & Motion-triggered alarm system with Arduino, PIR sensor, piezo buzzer, and LED alert. // first pic This ...

Figure an Arduino most matches the "Other" category. To be specific, it isn't an Arduino brand, it is a DigiSpark, but the trouble isn't with the device itself. The problem is with a buzzer. I got the ...