Our schematic consists on 3 elements which are: Photoresistor (LDR), Piezo Buzzer, 1 – 10 kΩ. The LDR can be connected any way you want because doesn’t have polarity. For resistance you can use from 1 ...

You can also see the USB mini-b connector which gives you access to the Arduino compatible ATmega328 microcontroller on the back. There is also a piezo buzzer for your alarm needs.

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 board contains an array of 6 by 7 LEDs in a charlieplexed configuration, a large piezo buzzer, two push buttons, an on/off switch, and a CR2032 battery holder to keep it on without the need ...