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Author Topic: Find analogIn frequency using FFT library  (Read 583 times)
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hi All

i have my android phone sending 4 different frequencies to the Arduino analog in using the earphones jack.
i need my arduino to find out which frequency is coming in, and do some actions according to the certain frequency.

my question is, how can i extract the input frequency and save it as an integer , (or at least a range ?)

i have downloaded the FFT lib and using fix_fft ()

also went through this discussion but still couldnt figure it out...
http://arduino.cc/forum/index.php/topic,38153.0.html

Thanks !
 
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Edison Member
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It might be best to change them to square waves and measure the period.
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In theory there is no difference between theory and practice, however in practice there are many...
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square waves +1

what are the 4 frequencies ?
how many pulses can the Arduino expect in one burst?

solution direction: pulseIn() might work or an interrupt based time-measurement if the waves are squared
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Rob Tillaart

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