This sound sensor module works with arduinos and many 3V-5V microcontrollers.AO: Analog Output – connect to any arduino analog input pinGND: GroundVCC: Power supply input range: 3V-5V.DO: Digital Output – Goes HIGH when sound is above a certain threshold. (Set by the pot)IMPORTANT: To calibrate the set point turn the potentiometer screw many times COUNTER CLOCKWISE until LED2 turns off. The sensitivity level can be seen at the analog output.