Sound used to triggering relay via Arduino

Hello Arduino experts

Hoping someone can help; I want to activate a relay switch using an audio signal. I have managed to use a piezo to trigger the relay but i need to phyically touch the piezo in order for it to work. I have an audio signal (a single click) that i want to use to trigger the relay - how can i do this????

best regards -hrm199

I wrote an article about this here: http://www.glacialwanderer.com/hobbyrobotics/?p=11 It uses a guitar amp to boost the signal from a mic and is sensitive enough to detect drips of water.

If you want a smaller/cheaper package, you should be able to get similar results with an electret microphone and an amplifying circuit. Search google for audio amplifier circuits if you want to go that route.

Cheers, that looks useful. i will explore both options. -H

You can find a circuit for a sound trigger at: http://www.hiviz.com/tools/triggers/triggers2.htm

You should be able to adept that to an arduino.