Find analogIn frequency using FFT library

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…,38153.0.html

Thanks !

It might be best to change them to square waves and measure the period.

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