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Detecting Loud Sound aka The Clapper Circuit — Parallax Forums

Detecting Loud Sound aka The Clapper Circuit

onecolumbyteonecolumbyte Posts: 2
edited 2004-11-18 18:15 in BASIC Stamp
I want to detect a sound threshold to trigger an action on my Boe-Bot.
I've searched the archives and google and come up with two kinds of answers 1) detailed circuits over my newbie head 2)general suggestions that surely would work if I could implement them.
I found a dedicated clapper circuit here http://home.maine.rr.com/randylinscott/dec97.htm. This looks like a great dedicated circuit but I was wondering how I could use the stamp to take the place of the "IC3" and/or other parts of the circuit. Other post suggest keeping the 555 timer to strech the pulse in order to make it easier to detect. Thoughts on this?
I simply want the stamp to complete a simple directive upon detecting the sound (ie turn servo x seconds using pulsout) so I won't need another detection to turn it off.

Code/Circuit Suggetions. Ideas?

Thanx

Comments

  • Jon WilliamsJon Williams Posts: 6,491
    edited 2004-11-12 21:53
    The pulse out of the 741 in the circuit is probably very narrow and you'd have to be sitting around waiting for it. I'd suggest using the 555 to stretch the pulse output (as in the schematic you reference), and you can use another pin to reset the 555 if you want to re-arm the circuit more quickly than the 555 timeout.

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    Jon Williams
    Applications Engineer, Parallax
    Dallas Office
  • onecolumbyteonecolumbyte Posts: 2
    edited 2004-11-18 18:15
    Jon thanks for your quick reply. I've been studying up to come back with an intelligent question. Lets hope it worked

    1) In my circuit the BS2 would take the place of IC3 Flip Flop. I'll want to use a pin to check the 555 timer and as you said I could use another pin to send the reset signal if I didn't want to wait for a rearm. OK so far right? If I wanted two claps I would simply have to add a counter variable for that pin right?

    My question arise from circuit mods by losing the flip-flop. First what does the 47 UF capcitor do in this circuit? Also RM the potiometer is for circuit tuning right? So I could adjust it to tune out background noise right? I have a LM359 dual ap-amp. can I use that in this circuit?

    Any more suggestions? this circuit posted at home.maine.rr.com/randylinscott/dec97.htm
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