Sound Blaster as Data Aquisition

[masmith]

At 12:38 PM 2/17/96 MDT, Darrell A. Norquay   wrote:
>
>Mark Boxsell wrote:
>
>>             Yes! ,This is exactly what I was wondering maybe we all have a
>> digital storage cro in our PC's after all! Has anyone out there seen any
>> articles on this, I think the 'line in' accepts 0 - 250mV so you would have
>> to put a front end of some kind on the thing.
>> Whoever works out a kit for this will make a fortune. I don't have time at
>> the moment so someone else will have to do it!
>
>The main problem with a sound blaster card is that it doesn't accept DC 
>signals.  The inputs are capacitor coupled so they block DC.  I think
>it will go down to about 10Hz minimum frequency.  It is made to digitize 
>audio, which probably wouldn't work for most sensor type inputs 'cause 
>they're mainly a slow changing DC signal.
>
>
run the dc thru a voltage to frequency convertor first, then digitize with
the sound blaster.
you could then save the result as a wave file (am assuming PC with windows
vs. eg mac)
the format of a wave file is probably on the internet "somewhere" and
"somewhere" on my hard
disk is a MATLAB file that can read it as an array of numbers that can be
FFTed, graphed, displayed
or whatever. (or run the pitch thru a lookup table to reverse the v2f
converter.)
Matt Smith
masmith089 at qnet.com
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