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 ...

I just received my RC522 RFID reader and made this simple Arduino access control system that uses the reader, a buzzer for the alarm and a relay shield for the security system. The relay can be used ...

The humble piezo disc buzzer is much more than something that makes tinny beeps in retro electronic equipment, it can also be used as a sensor. Tapping a piezo buzzer gives an interesting waveform,… ...