FFT_N_SAMPLES = 4096;
Fs =31250;
alpha = 3.9
    
%% input data
% read data from file
filename = 'ADC.CSV';
fid=fopen(filename','rt'); 
data_in = fscanf(fid, '%d,');
fclose(fid); 
%% windowing
for i=1:FFT_N_SAMPLES
        %Gaussian:
        tmp_n = abs(i - (FFT_N_SAMPLES)/2);
        tmp = alpha * tmp_n / (FFT_N_SAMPLES/2);
        coeff = exp(-0.5 * tmp*tmp);
        data_win(i) = data_in(i) * coeff;
end
%% fft
data_fft = fft (data_win,FFT_N_SAMPLES);
%% magnitude
for i=1:FFT_N_SAMPLES/2
    data_fft_abs(i) = 2.0 * abs(data_fft(i));
 end
%% maximum searching
max = data_fft_abs(1);
n_bin_max = 1;
for i=1:FFT_N_SAMPLES/2
    if (max < data_fft_abs(i))
        max = data_fft_abs(i);
        n_bin_max = i;
    end
end
%% Gaussian interpolation
			m1 = data_fft_abs(n_bin_max-1);
			m2 = data_fft_abs(n_bin_max);
			m3 = data_fft_abs(n_bin_max+1);
            top_part = log (m3/m1);
            bot_part = 2*log(m2*m2/(m3*m1));
            d = top_part/bot_part;
% f = ( i + d ) * ( sr / n )
            n_bin_response = n_bin_max + d;
			Frequency_Response = (n_bin_response-1) * Fs / (FFT_N_SAMPLES)