[sdiy] understanding direct AVR ADC...multiple channels

[Matthew Smith]

Quoth Mattias Rickardsson at 06/03/12 19:03...
...
> The other day we were trying to find the cause of an ugly strong 3.9
> kHz tone in a recording. It turned out that it was the result of a
> soundcard converting 48 kHz to 44.1 kHz by simply dropping each 12th
> sample. It didn't sound too nice! :-)

Another cautionary tale.

Sample rate mis-matches can lead to all sorts of issues, and lots of 
wasted debugging time, if not checked at the outset.

I use a Zoom H2 as my microphone for Skype calls. If set to 44.1ksps 
(the default,) my voice sounds weird, and feminine (which it doesn't 
normally.) Setting to 48ksps, quite normal.

That's why, in an embedded system, I'd want to make sure that the ADC 
and DAC rates are the same. Mix'n'match is a BAD idea.

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815