sound recognition

[w1]

Hi,

I am trying to develop a program which should respond on a certain DTMF tone. For example; if digit 1 is pressed an led should light up. The only problem I am having is how to recognize the specific frequency and make a led work. If someone of you could please help that would be greatly appreciated.

My program is attached.

Thanks a lot.

[naserkhan]

Hello..

I have exactly the same issue...... can someone from NI help/guide us please...much will be appreciated..............:)

[ToeCutter]

Take an FFT every, say, 0.25s. Monitor for a peak at the correct tones then if you see it, light your LED.

[naserkhan]

can you please elaborate on that as I am not extremely good in labview.......so I would really appreciate if u can expalin to me as if u were to explain an infant( so to say)...:)

thanks

[William1225]

Hi, w1,

I wonder if you just want to extract the tone(frequency) of the acquired data?

Could we use the "Extract Single Tone Information.vi" in the Signal Processing Toolkit in your issue?

[w1]

Hi William,

Thanks a lot for the VI you posted. But unfortunately, I don't have this toolkit plus I am trying to make use od the microphone (Audio data aquisition) while this program is doing something with sin wave. 

if you have some other idea please let me know.

thanks

[Larry.C]

Hi W1,

Would it not be possible to use the tone measurement express VI?:

Otherwise could you not use the spectral measurements express VI and use the highest peak found in the power spectrum as your tone frequency information.

Kind Regards,

[w1]

Hi Laurence,

Well basically I know the frequency of the sound being played. The bit where I am stuck is when a certain frequency is detected in FFT, how can I use that particular frequency to light up a led as an output ?

Thanks

[johnsold]

Look at Extract Multiple Tone Information.vi from the Signal Processing >> Waveform Measurements palette. When the frequency is within tolerance, compare the amplitude to a threshold. If the amplitude and frequency are both accpetable, then turn on the LED.

Lynn