Digital (pwm) pin D3 drives the piezo-buzzer through a PNP transistor ... and connects pins 4 and 5 (UART) to Arduino pins 0 and 1. The APC220 module (see next image) has a total of nine pins (only ...

The new Arduino project is powered by an Arduino ... For playing the music, it uses the BY8001 MP3 Player module and for the alarm clock it uses the DS3231 Real Time Clock module.

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 Velleman svm06. It says it is rated at 3-7VDC ...

He’s using an Arduino Uno and an Ethernet breakout board to hook it up to the network. This allows him to send text messages to himself when the alarm system is armed, disarmed, or triggered.