Low frequency FSK demodulation, less than 100kHz

[ademedeiros]

Hi,

I am trying to demodulate an ultrasonic FSK signal, which will be less than 100kHz, most likely 20-45kHz.  I am looking for a simple way to decode this, I have tried the Delay & Multiply method, but I have not had much sucess with it. 

Are there any example VI's showing this?

[Esteban_B]

Hi ademedeiros,

I was able to find this example in our website (ni.com/code) and it is a modulation/demodulation VI for FSK.

I hope this helps!

Regards,

[ademedeiros]

Hi Steve,

Thankyou for your help. That example uses the Modulation toolkit as well as RF hardware. I am looking for an example, or guidance in demodulating FSK acquired by an M-Series Daq.

[Esteban_B]

Hi ademedeiros,

Sorry for that, I found these two other examples:

Implement FSK with X-Series and DAQmx

Modulation Toolkit 2-FSK to Baseband Example Using DAQmx

I hope this helps!

Regards,

[ademedeiros]

Hi Steve,

Thanks again for your help. These examples are extremly helpful, but they are for modulation, not demodulation. Is there anyway to use DaqMX and the toolkit for demodulating FSK?

[Esteban_B]

Hi ademedeiros,

The Modulation Toolkit has a FSK demodulate function, you can use this for the demodulation phase. What you can try to do is to set up a analog acquisition task and send the data that you get to the demodulate VI. That should work for your need.

Regards,

[Esteban_B]

Seems that one of the links is broken, this is the correct one:

Modulation Toolkit 2-FSK to Baseband Example Using DAQmx