unfortunately im a complete novice with all things aurdino, but I need to create a sound triggered device, and a friend of mine that uses aurdino has suggested that it may provide the answers. I am trying to create a system where a sound triggers a pneumatic piston. With the piston there will be no variation with speed / force, it will be a simple on / off. Hopefully it will be triggered by a microphone sensor. When the sound picked up reaches a certain volume, say the clap, it will trigger the piston to move once.
Hopefully the description isnt too vague, and any advice on the software / hardware setup will be really really appreciated!
I got something similar up and running just plugging the output from the amp circuit into the sound trigger circuit. Jeff seemed to think it might work without the amp circuit but I never tried it that way. You don;t actually need an arduino in this circuit, although I had originally run the amp circuit linked above into an arduino to calculate the amplitude which was then used as a trigger (there is inofrmation on how to do this in Physical Computing).. but it turned out to be a bit overkill.
If you just want on/off I imagine you would only need minor modifications, replacing the motor end of the trigger circuit with whatever your piston requires to trigger it.
I've been triggering a camera flash using a simple piezo with no amplification. Try the "knock" analog I/O tutorial on the learning page to see if it is sensitive enough for your application. A clap is plenty loud.
Aaah, finally someone who knows how to keep things simple!! So tell me, did you have any problems in finding the right threshold? And what resistor did you use for the piezo? I have a 1.2 Mohms, does it matter at all for the signal you obtain?
My specific problem is that at threshold = 200 I still "acknowledge" too many sounds, while after 270 it suddenly doesn't hear anything... sooo weird. What threshold did you have for a handclap?