• jlynn
  • New member
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  • Registered: 2011-02-20
  • Posts: 1

Topic: Audio interface

I'm looking to write a program in C, that takes input from the MIC in on the Chumby
Hacker Board.  Would the best way to interface with the MIC input be through the
/dev/dsp or /dev/audio device, or is their some other sound library to use on the Chumby?

I'm new to programming on the Chumby, but it seems it would be easier to go through
one of the standard linux devices, rather then direct control via the chip registers.  Any
insights would be of help.

Thanks,
Jonathan

2 Reply by wampumphysics (edited by wampumphysics 2011-02-24 11:13:08)

  • Registered: 2011-02-06
  • Posts: 3

Re: Audio interface

I believe in theory you can just open and read dev/audio and get straight amplitude data. The way the i.MX233 mux scheme is set on startup, I think you'll first have to pipe in the mic (using dev/mem for register control). The datasheet has a pretty good walkthrough of this process. If you want any control over the signal though, (i.e. sample rate, gain, filtering) you'll have to do it all in the mem file.

  • Duane
  • Duane
  • Blue Octy
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  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,209

Re: Audio interface

The device supports ALSA - it's probably best to use that to use the MIC.

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