DSP sampling signal

[perchick]

hellow

im implementing a graphic EQ on dsp board c6713 with labview DSP target. my problem is when im sampling my audio input at 48KHz and then adding FFT i hear metalic sound. i want to sample my processed signal at 8KHz (im guessing my DSP cant handle the anount of data for FFT algorithm)

in other wards, i want to take data for my FFT at a rate of 8000 samples per second and show it on a graph while all other signal processing will continue at the audio in sampling rate

Thanks in advance!

[Philosophe]

I see that you are using a c6713 dsp board as hardware. What specific software are you using to interface with the hardware? Are you using LabVIEW? Any toolkits? 

Just a note: we do not support any technical information with regards to third party hardware. Any information pertaining to the dsp board will have to go through third party channels.

[perchick]

hi

Im using only Labview DSP target, there is no other software to communicate with the target.

im using the DSP module on LABVIEW 8.6. I also have digital filter disgn toolkit. my information (input) is sampled at 48KHz. I need the signal input for the FFT to be at a rate of lower then 8KHz (preferably much slower, i need the FFT either for a frequency graph or for display of the energy of each channel)

is there a way of doing that? for loop for delay wont work. the DSP cant handle the simplest loop.

thanks in advance!

[Philosophe]

It seems that this function should do the trick. The function block is called "Decimate (Single Shot)." It can be found in the functions pallete at Signal Processing»Signal Operation»Decimate (Single Shot). It will allow you to take every nth sample fo data.

In addition, here is an explanation of the function as well.

http://zone.ni.com/reference/en-XX/help/371361K-01/lvanls/decimate/

[perchick]

It does seems that this function would do the trick. the problem is tht with DSP TARGET i do not have this function. i do not have ny of the SIG OPERATION functions. is there a way to import some function to DSP module?

if not, there is the option of communicating with my board using RTDX and CCS. it seems much more complicated that DSP target. i was wondering if there is some kind of guid for this? do you think its best to communicate with my board this way?

Thank you for your help

[Philosophe]

Do you have any of the basic functions in LabVIEW?

If so, this function can also be found in the array palette. Its called "Decimate 1D Array". Then expand the function block out . Wire the data into the function and wire the 6th slot out to a waveform graph.

Let me know how this works.