View Full Version : Clap detector?

05-12-2006, 12:25 AM
Has anyone built a simple clap detector for the BS? Im trying to do this without using an amp. Maybe a piezo sensor? I'd like to do this via RCtime. Thanks, nik

PJ Allen
05-12-2006, 12:51 AM
I think that a crystal microphone, piezo sensor,·may not have enough output (voltage) for the RCTime to make effective use of.· Maybe you can find one at·a·thrift store, or Goodwill,·for cheap to do experiments with (like the microphones made for older tape recorders.)
http://hyperphysics.phy-astr.gsu.edu/Hbase/audio/mic3.html (http://hyperphysics.phy-astr.gsu.edu/Hbase/audio/mic3.html)
http://www.radioshack.com/product/index.jsp?productId=2123172&cp=&origkw=microphone&kw=microphone&parentPage=search (http://www.radioshack.com/product/index.jsp?productId=2123172&cp=&origkw=microphone&kw=microphone&parentPage=search)

Post Edit --
My assumption is that your intention is as a hand-clap detector and not some other sort of clap detector.

Post Edited (PJ Allen) : 5/11/2006 7:10:46 PM GMT

Chris Savage
05-12-2006, 12:57 AM
If you used an op-amp you may be able to get a signal from a microphone or Piezo to be detected by the BASIC Stamp as a simple HIGH/LOW signal.

Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

Charlie Johnson
05-12-2006, 02:15 AM
LOL, I had a very different visual when I saw the subject.· http://forums.parallax.com/images/smilies/nono.gif

Vern Graner
05-12-2006, 02:59 AM
nika said...
Has anyone built a simple clap detector for the BS? Im trying to do this without using an amp. Maybe a piezo sensor? I'd like to do this via RCtime. Thanks, nik

Are you looking for an impact noise detection (i.e. "clap on" - "clap off") or are you looking to detect the level of applause from a large crowd (i.e. a applause meter to allow audience noise to determine a winner)?



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A.C. fishing
05-12-2006, 04:27 AM
What about the stamp audio system in the projects?


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05-12-2006, 09:50 AM
Just a simple hand clap high/low signal like what was earlier described. I'm going to have to look into opamps. If anyone has done this before leme see how you did it. Thanks, nik

PJ Allen
05-12-2006, 10:01 PM
Here's an experimenter's kit for $1 more than the microphone that I linked to· -- http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=151204 (http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=151204)

It comes with an electret mic.

05-13-2006, 02:46 AM
An OP-Amp set up as a comparator should work fine. Set up a 2nd stage OP-amp to give an indication of the input going over a certain threshold (a clap...not THE clap).

You'll probably have to amplify the mic.....

Don't forget to add in a small pot so you can adjust the comparators reference to tune in for the clap level.



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