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35 lines
523 B
35 lines
523 B
6 years ago
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% adc_sfdr_ut.m
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% David Rowe Aug 2015
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%
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% Processes data collected from STM32F4 or SFDR testing of ADC
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s = load_raw("~/stlink/adc.raw");
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Fs = 2E6;
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N = 1024;
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num_frames = length(s)/N;
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h = hanning(N);
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XdB = zeros(N/2,1);
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for i=1:num_frames
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x = s((i-1)*N+1:i*N);
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X = fft(x .* h);
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XdB += 20*log10(abs(X(1:N/2)));
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end
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XdB /= num_frames;
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XdB -= max(20*log10(N));
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figure(1)
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clf
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plot((0:N/2-1)*Fs/(1000*N), XdB)
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grid
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ylabel('Amplitude dB')
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xlabel('Frequency (kHz)');
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axis([0 Fs/(2*1000) -30 80])
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figure(2)
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clf
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plot(s)
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