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Audio-controlled LEDs

  1. Apr 15, 2007 #1
    I am trying to control a bunch of LEDs to respond to different audio frequencies.

    I have a microprocessor with A/D converter and know how to use these, but I have no idea how to go about the rest of it.

    Thanks in advance!
  2. jcsd
  3. Apr 16, 2007 #2


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    Do you mean for this thing to be responsive to an actual audible signal, as through a microphone, or simply the electronic signal that would drive a speaker?
    I know nothing of electronics, but if it's the latter scenario I would suggest that you check into schematics for the bar graphs on graphic equalizers or the sequencers used by bands for their lighting effects.
  4. Apr 16, 2007 #3
    I'm trying to do it through a microphone.

    I have an idea of how I am going to control my LEDs, my main problem now is figuring out what is the best way to receive the audio signal (eg. what's the best type of microphone to use) and how to filter out the different frequencies.
    Last edited: Apr 16, 2007
  5. Apr 16, 2007 #4


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    Hmmm... Would you then be able to still use the graphic equalizer circuitry by running your mike through a regular pre-amp?
    I have plans somewhere for similar 'colour organs', but they're based upon transistors and small light bulbs (60's-70's Popular Electronics magazines):redface: .
  6. Apr 16, 2007 #5
    sorry, to be honest I am completely lost as to what I could or could not use.

    I did a quick search, and it does seem like I might be able to use similar circuitry.. the main problem is that so far, for all the circuits i've looked at, there are some parts of them I don't understand yet.
    it's a little late right now so I can't really think, will look into it in the morning.

    thanks for your help so far!
  7. Apr 16, 2007 #6


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    Don't apologize... you know more than I do. I have no experience with microprocessors, and have never heard of a A/D converter.
    As for the help, there really wasn't any. I'm just throwing out random ideas in the hope that one might be useful.
    Once Berkeman and a few others weigh in, you'll have some real guidance.
  8. Apr 16, 2007 #7


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    Last edited: Apr 16, 2007
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