How to calculate the frequency of a signal obtained through a computer's sound card

[Grant S]

I wrote a program that gets an audio signal from my computer's sound card.  My goal is to be able to play a note on a keyboard and get that note's frequency.  Can anyone show me some code that might help me out?  Or at least point me in the right direction?

[chrisger]

hi there

please search the examlpes database (see scrennshot).

[Grant S]

The graph is pretty neat but other then that, it won't work, the Frequency sticks around 7.  Is there are other code I could look like?

[unclebump]

Search the examples for frequency and open this file.

C:\Program Files\National Instruments\LabVIEW 7.0\examples\measure\maxmpl.llb\Basic Single Tone Measurements.vi

[chrisger]

hi there

make sure you chose the correct device number of your mic.

[Grant S]

I'm sure I've got the right device number, I can get the amplitude and graph the signal.  I just can't get the frequency and it's a little frustrating.  Thanks for your help though.

[unclebump]

Are you recording stereo or mono data??

[Grant S]

mano

[chrisger]

hi there

what is the unit of "7"? if you mean 7Hz then remember that most sound cards have a range of 20Hz-20.000Hz, so in that case just ignore that data (low frequency noise). send us some data and code so we can have a look.