The SparkFun Sound Detector is a small, flexible, and easy to use audio sensing board. It offers three different outputs – the audio signal, a digital output (HIGH when audio is detected), and an analog output representing amplitude. Each one is independent – so you can pick and choose which ones you want to use!

The envelope output allows you to read amplitude of sound by measuring the analog voltage. The gain can be adjusted with a through-hole resistor to change the threshold of the binary (gate) output pin as well. The hookup guide below details how to change the gain.

This version of the board ships with the header soldered in place. The header is breadboard compatible and can also be connected using jumper wires – no soldering required!