By connecting a piezo sounder to a digital output pin, you can create a wailing alarm sound. It's the same principle that you used in Project 7 when creating a pulsating lamp via a sine wave, but this time you replace the LED with a piezo sounder or piezo disc.
|Piezo Sounder (or piezo disc)|
|2-Way Screw Terminal|
First, make sure your Arduino is powered off by unplugging it from the USB cable. Now take the piezo sounder and screw its wires into the screw terminal. Connect the ...