Good FFT routines for sound card?

Hello Martin,

It won't run under Win2000 or NT and doesn't support laptop sound cards. Other than that it looks like a great SW, seems worth the registration fee. Have to keep my eyes peeled for the new Windows version.

Regards, Joerg

I think Daqarta is still around, very DOSsy, but have a word with Bob Masta at daqarta.

martin

Hello Martin,

Interesting. The only weird thing is that there is an order sheet but they do not seem to disclose any pricing. Really strange.

Regards, Joerg

Hiya Joerg, Havent been to Daqarta site in some time, he was promising windows gui a Long Time Ago...... maybe Sound Technology, basically Darqarta with a fancy GUI. You buy the modules you want. Might have a url somewhere,

shuffle ancient hard drives into action hi de ho, dum dee dum, where is Slartibardfast when you need him?

nope,

sorry

martin

martin

Find a copy of gram.exe

Steve Roberts

If what you want is a readymade program I recommend the freeware gram

5.01. The author's site seems to be down but do a search for gram50.zip and you'll find several places for download.

- YD.

--
Remove HAT if replying by mail.

Hello Steve,

Thanks, I'll try it. I heard this program name before in the ham radio community but thought it was an offline tool. From what I found via Google it seems to also run realtime.

Regards, Joerg

Hello YD,

On advice from Steve I found one zip file at a German site. Don't know its version yet but hopefully will have time to try it on the weekend.

Long term I want to do more, like testing filter routines. But then I'd have to migrate from the leather seat back to individual files and C routines (which I have).

Regards, Joerg

Hi,

If it is only for testing purpose, not to compile in an executable, Matlab may help you just fine.

AUDIORECORDER(Fs, NBITS, NCHANS)

will record on-the-fly, using any sample rate supported by your card. By default, it will use Windows default input device but you can override this. Resulting data can be in many bit depth (8, 16, 24) and mono or stereo. Data is returned as an integer array.

You can then FFT the recorded array and do anything you want with it.

Last time I used this function, I made an automatic piano tuner with it :) Have fun!

Francois Choquette

Joerg wrote:

Hello Francois,

That is a great way to do it. However, except for academic use Matlab is expensive IIRC and I believe they want yearly fees.

I did a kludge to tune our piano. Wrote a small calc routine in a spread sheet that also allowed me to add the small correction factor for tempering. This spit out a frequency table for all strings. I could have somehow fed that into the generator via GPIB but just printed it out and dialed it in while at the piano.

The problem is that with our temperature extremes this old piano doesn't hold tune for too long. But it does sound like one of those good old saloon pianos.

Regards, Joerg

Try these free

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

i have Pascal code for FFT if you wish to look at it.

--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Hello Boris,

This one appears to be Linux only.

That looks very good. Thank you. I will try it out. From reading that site I happened upon another FFT program here:

Regards, Joerg

Hello Jamie,

Thank you but I can't read Pascal. A wee bit of C and assembler but I am not really a SW specialist. However, at some point I'll have to dive in to try something out. Then the problems are mostly not so much the C routines where I have a ton of "canned" versions that came with books. The real problems is talking to the sound card and all kinds of Windows interfaces. Maybe I'll do that in DOS ;-)

One issue is the miserably shallow documentation of "modern" computers. On mine they only tell you that the sound comes in via an Analog Devices chip but not which one. That pretty much "sums up" the HW docs for sound. It is pathetic.

Regards, Joerg

i have a good suggestion for you. find your self a copy of Delphi. there are lots of code out there for putting the sound card in record mode to capture the PCM bits. i can even supply code for you so that you can adapt to windows coding. my URL below will show an app that uses the sound card to decode and encode Slow Scan Tv. it using FFT coding as an option but defaults to zero crossing on initial install. i find for rather clean tones, i get better resolution on detect with out chewing up CPU time.

FFT has a little problem with precision that can be helped out using larger Float numbers at the cost of CPU time.

--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Hello Jamie,

Thanks, but I don't want to become an expert in code. Just trying to FFT something. So far I found that the Rutgers program is pretty bare bones but performs the best (fastest).

Later I may have to try to do FFT in an MSP430. I am not looking forward to that as it will be like cramming 15 people into a VW Beetle (has been done...). Also, it's not going to be the MSP430 on steroids, no HW multiplier here :-(

Regards, Joerg