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How to detect a sound event? — Parallax Forums

How to detect a sound event?

ArchiverArchiver Posts: 46,084
edited 2000-09-20 01:27 in General Discussion
Hi there,

I'm still looking for the easiest way (or to be more accurate, the one that use
the minimum of external components) to detect a sound event as a hand clap
etc... with the BS2.
I just want to know that there has been a noise. No quantity or quality
information needed.
Any ideas ?

Nicolas

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-09-19 02:48
    At 06:07 PM 9/18/2000 -0700, you wrote:
    >Hi there,
    >
    >I'm still looking for the easiest way (or to be more accurate, the one
    >that use the minimum of external components) to detect a sound event as a
    >hand clap etc... with the BS2.


    An electret or carbon microphone will sense sound. The carbon transmitter
    (as found in older phones) will produce electricity on it own. The others
    types of mikes require separate power and/or amplification to be used with
    a Stamp.

    More than that, others will have to offer, but that's a start.

    >I just want to know that there has been a noise. No quantity or quality
    >information needed.
    >Any ideas ?
    >
    >Nicolas
  • ArchiverArchiver Posts: 46,084
    edited 2000-09-19 03:29
    Hi Bruce,

    Thanks for your comments on my Cell (or Packet Radio)
    interface, if you don't mind, could you elaborate more
    on your concept. How would I get the Stamp to
    physically connect to a cell phone, or were you
    implying using packet radio to perform this? I guess
    Packet certainly sounds easier.

    About the Stamp detecting sound (clap), have you
    thought about using a piezo transducer? You can vary
    the threshold intensity to only allow for a clap (ie.,
    it won't pick up every single sound that occurs).

    Thanks for your help!

    Todd

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  • ArchiverArchiver Posts: 46,084
    edited 2000-09-19 04:09
    At 07:29 PM 9/18/2000 -0700, you wrote:
    >Hi Bruce,
    >
    >Thanks for your comments on my Cell (or Packet Radio)
    >interface, if you don't mind, could you elaborate more
    >on your concept.

    I'm only aware of the PIC application which I once saw on a ham website.
    Take a look here: [noparse][[/noparse] http://www.tapr.org/tapr/html/kitsf.html ].

    > How would I get the Stamp to
    >physically connect to a cell phone, or were you
    >implying using packet radio to perform this?

    The Stamp isn't capable of large scale data manipulation, although some
    amazing things have been done when it's pressed to its limits. Some cell
    phones have a direct data connection, and I believe it's used for fax
    transmissions (not sure). I have a VERY OLD Radio Shack cell phone, which
    is a LUGGABLE (NOT small), but has an adapter which fits between the
    handset and the transceiver. The RS-232 port from the Model 100 could be
    directly connected to this interface. The ROM BASIC of the TRS Mod 100
    could then be used to transmit data over the cell phone in 1-9-8-7 !
    My only point being - if it could be done then, I would suspect it still
    can be.

    > I guess
    >Packet certainly sounds easier.
    Not sure -
    How are you planning on packetizing the data on a Stamp ? Unless it is a
    very small amount, I would think you'd run out of RAM awfully quickly.
    You have the additional problem of verifying the transmission, if
    relaibility is of any concern. Please don't let this detract from your
    efforts, however. Have at it !

    >About the Stamp detecting sound (clap), have you
    >thought about using a piezo transducer? You can vary
    >the threshold intensity to only allow for a clap (ie.,
    >it won't pick up every single sound that occurs).

    That wan't my "project" - sorry. I suppose piezo + an op-amp might provide
    enough voltage, but that is out of my league.

    >Thanks for your help!

    Sure


    >Todd
    >

    Bruce


    >__________________________________________________
    >Do You Yahoo!?
    >Send instant messages & get email alerts with Yahoo! Messenger.
    >http://im.yahoo.com/
  • ArchiverArchiver Posts: 46,084
    edited 2000-09-20 01:27
    A simple condenser mic fed to an op-amp can produce sufficient signal
    level. Once problem may be the speed at which the sounds occurs, it
    may be missed as it would be a sharp spike.

    I don't have the configuration handy, but an op-amp may be setup with
    a few components as a peak-hold device. It will hold the highest
    voltage and slowly bleed off allowing ample time to sense it (some
    stereos show sound level peak bar-graphs the slowly go back down--
    same idea).

    Pick up the op-amp cookbook for that and other good op-amp circuits.
    In these days of digital, we tend to forget how cheap, simple and
    easy analog devices can be.

    -Martin Hebel
    Southern Illinois University Carbondale, Electronics Management
    http://www.siu.edu/~imsasa/elm
    and
    SelmaWare Solutions
    www.selmaware.com

    --- In basicstamps@egroups.com, "Nicolas Fournel"
    <Nicolas.Fournel@f...> wrote:
    > Hi there,
    >
    > I'm still looking for the easiest way (or to be more accurate, the
    one that use the minimum of external components) to detect a sound
    event as a hand clap etc... with the BS2.
    > I just want to know that there has been a noise. No quantity or
    quality information needed.
    > Any ideas ?
    >
    > Nicolas
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