decoding sound
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Friends,
I'm trying to get my stamp to recognize sounds of a certain pitch. It
doesn't have to be exact, I'd just like it to be able to respond to sound
in a way other than volume, Can anybody clue me in on where to start with
this? I have some tone decoder chips (lm567) but it seems like they are for
touch tone phones. Can I adjust them to recognize a wider range of tone?
I'd like my stamp to act like a sophisticated sound to light kit, where it
lights different things depending on what notes or frequencies it hears in
music.
Any advice appreciated!
Raoul
I'm trying to get my stamp to recognize sounds of a certain pitch. It
doesn't have to be exact, I'd just like it to be able to respond to sound
in a way other than volume, Can anybody clue me in on where to start with
this? I have some tone decoder chips (lm567) but it seems like they are for
touch tone phones. Can I adjust them to recognize a wider range of tone?
I'd like my stamp to act like a sophisticated sound to light kit, where it
lights different things depending on what notes or frequencies it hears in
music.
Any advice appreciated!
Raoul
Comments
circuitry to condition the audio for detection by the stamp's input pin.
Maybe zero crossing and level shifting or amplification / conditioning.
leroy
raoul vaneigem wrote:
>
> Friends,
>
> I'm trying to get my stamp to recognize sounds of a certain pitch. It
> doesn't have to be exact, I'd just like it to be able to respond to sound
> in a way other than volume, Can anybody clue me in on where to start with
> this? I have some tone decoder chips (lm567) but it seems like they are for
> touch tone phones. Can I adjust them to recognize a wider range of tone?
>
> I'd like my stamp to act like a sophisticated sound to light kit, where it
> lights different things depending on what notes or frequencies it hears in
> music.
>
> Any advice appreciated!
>
> Raoul
>
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of the message will be ignored.
>
>
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>
>Friends,
>
>I'm trying to get my stamp to recognize sounds of a certain pitch. It
>doesn't have to be exact, I'd just like it to be able to respond to
sound
>in a way other than volume, Can anybody clue me in on where to start
with
>this? I have some tone decoder chips (lm567) but it seems like they
are for
>touch tone phones. Can I adjust them to recognize a wider range of
tone?
>
>I'd like my stamp to act like a sophisticated sound to light kit,
where it
>lights different things depending on what notes or frequencies it
hears in
>music.
>
>Any advice appreciated!
>
>Raoul
You could possibly use a number of band-pass filters, each tuned to
different centre frequencies. They are commonly used in speakers to
split the audio frequencies up so that the correct frequencies are
sent to each speaker.
They are quite simple to construct from combinations of inductors and
capacitors. You tune them to a certain centre frequency and any
frequency above or below this selected frequency is gradually
attenuated. Do a web search on speaker crossover design.
The other way, which is much more complex and maybe beyond the scope
of the Stamp would be to use an analog to digital converter and do
some sort of DSP on the audio signal.
Paul Lugger
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stamp's threshold voltage, the count command would be ideal for this. As long as
the tone is a single note (not a chord) you should be able to determine its
frequency within the software without any filtering. Unless the tones are
changing at regular intervals you may need some way to determine the start of a
new tone, though.
Dan
Leroy Hall <leroy@f...> wrote: Pulse in might work for this, but you may
need some rather sophisticated
circuitry to condition the audio for detection by the stamp's input pin.
Maybe zero crossing and level shifting or amplification / conditioning.
leroy
raoul vaneigem wrote:
>
> Friends,
>
> I'm trying to get my stamp to recognize sounds of a certain pitch. It
> doesn't have to be exact, I'd just like it to be able to respond to sound
> in a way other than volume, Can anybody clue me in on where to start with
> this? I have some tone decoder chips (lm567) but it seems like they are for
> touch tone phones. Can I adjust them to recognize a wider range of tone?
>
> I'd like my stamp to act like a sophisticated sound to light kit, where it
> lights different things depending on what notes or frequencies it hears in
> music.
>
> Any advice appreciated!
>
> Raoul
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and Body of
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Do You Yahoo!?
Yahoo! Health - your guide to health and wellness
[noparse][[/noparse]Non-text portions of this message have been removed]
kHz.
Certainly within the range music. Problem is that you need one 567 for
each freq, you want to detect.
Another solution is the LM2907/LM2917 Frequency to Voltage
converter. Pair that with a DAC and you should be able to detect any
freq. within the range of human hearing.
Check out:
A Microphone Frequency Sensor
by Eli Kolberg
http://www.seattlerobotics.org/encoder/200112/elik.htm
he's done most of the design work already - just supply a DAC (MAX187 or
similar) and you should have yourself a very flexible system.
Best, Pete.
________________________________________________________
Peter W. Houlihan, (413) 538-3091, phouliha@m...
Mellon Postdoctoral Fellow, Center for Environmental Literacy
Mount Holyoke College, South Hadley, MA 01075
Visit our website at:
http://www.mtholyoke.edu/proj/cel/index.html
________________________________________________________
On Fri, 26 Apr 2002, dan fox wrote:
> Date: Fri, 26 Apr 2002 19:25:42 -0700 (PDT)
> From: dan fox <dan_fox2002@y...>
> Reply-To: basicstamps@yahoogroups.com
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] decoding sound
>
>
> If you can get the sound converted to electrical pulses that are above the
stamp's threshold voltage, the count command would be ideal for this. As long as
the tone is a single note (not a chord) you should be able to determine its
frequency within the software without any filtering. Unless the tones are
changing at regular intervals you may need some way to determine the start of a
new tone, though.
>
> Dan
>
> Leroy Hall <leroy@f...> wrote: Pulse in might work for this, but you may
need some rather sophisticated
> circuitry to condition the audio for detection by the stamp's input pin.
> Maybe zero crossing and level shifting or amplification / conditioning.
>
>
> leroy
>
> raoul vaneigem wrote:
> >
> > Friends,
> >
> > I'm trying to get my stamp to recognize sounds of a certain pitch. It
> > doesn't have to be exact, I'd just like it to be able to respond to sound
> > in a way other than volume, Can anybody clue me in on where to start with
> > this? I have some tone decoder chips (lm567) but it seems like they are for
> > touch tone phones. Can I adjust them to recognize a wider range of tone?
> >
> > I'd like my stamp to act like a sophisticated sound to light kit, where it
> > lights different things depending on what notes or frequencies it hears in
> > music.
> >
> > Any advice appreciated!
> >
> > Raoul
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
> Do You Yahoo!?
> Yahoo! Health - your guide to health and wellness
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>If you can get the sound converted to electrical pulses that are above the
>stamp's threshold voltage, the count command would be ideal for this. As
>long as the tone is a single note (not a chord) you should be able to
>determine its frequency within the software without any filtering. Unless
>the tones are changing at regular intervals you may need some way to
>determine the start of a new tone, though.
I'd guess amplifying the tones with a moderately high gain op amp powered
by a single 5-volt supply would do the trick as far as signal conditioning
goes. The peak should be close enough to 5 volts, well over what the stamp
needs to trigger an input, and the valley should be 0.7 or below, good
enough to be a logic low.
Jim H