Final Circuit Python frequency locator for Adafruit Clue

code.py

import array
import board
import audiobusio

import ulab
import ulab.extras
import ulab.vector

fft_size = 2048

# instantiate board mic
mic = audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA,
                       sample_rate=16000, bit_depth=16)

#use some extra sample to account for the mic startup
samples_bit = array.array('H', [0] * (fft_size+3))

# Main Loop
def main():
    max_all = 10

    while True:
        mic.record(samples_bit, len(samples_bit))
        samples = ulab.array(samples_bit[3:])
        #print(len(samples))
        spectrogram1 = ulab.extras.spectrogram(samples)
        # spectrum() is always nonnegative, but add a tiny value
        # to change any zeros to nonzero numbers
        spectrogram1 = ulab.vector.log(spectrogram1 + 1e-7)
        #print(len(spectrogram1))
        spectrogram1 = spectrogram1[1:(fft_size//2)-1]
        max_curr = ulab.numerical.max(spectrogram1)[0]
        
        index=0

        for item in spectrogram1:

            if item == max_curr:
                print((index+1)*(16000/fft_size))
            index=index+1


main()