OK, so I think the audio capes are the best advice at this point. What I'm doing is developing software to sample different types of sounds and do some audio fingerprinting. So I should stick to the software development and not make my life more difficult with wiring up mikes/adcs/dacs/mini-speakers :)
I really appreciate the education on this, though. Thanks so much for your time! -Jim On Tuesday, January 20, 2015 at 9:48:36 PM UTC-5, Graham wrote: > > Jim: > > You didn't say what your end goal is, so I have to guess what you are > trying to do. > > The CLK in question is the SPI CLK, not a sampling clock. So, should you > want to use > this ADC, (and there are reasons you might not want to) You will probably > be better off > using one of the two SPI interfaces, and not just any four GPIO lines. > > This is not an audio ADC. This is an instrumentation ADC. The differences > are that > audio codecs are usually twos-complement output, and use a sampling clock > to get very > regular sampling intervals, and include the necessary input Nyquist filter > as a > built-in as part of the chip. > > This ADC only does one conversion when you access it and ask it with the > SPI bus. > You could do some software calisthenics to call for the samples very > regularly, but will > get a lot of jitter in the sampling because of the nature of (most) BBB > Operating systems. > This will show up in the audio as distortion. > > You could do the one-sided data to two's complement conversion in software. > > You could add a Nyquist filter in hardware between the microphone and the > input > to this ADC. > > So, it all depends what you are trying to do. If you want a minimum > quality audio > input and an educational experience in the topics I listed above, keep > going. > > If you are trying to get a quality audio input for something, look at one > of the > audio capes for the BBB. Or pick a real audio ADC for your hardware > design. > > --- Graham > > == > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
