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analyser.cpp
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analyser.cpp
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#include "analyser.h"
#include "math.h"
constexpr double NOISE_LIMIT = 512.0 * 4;
constexpr double BAR_HEIGHT_MODIFIER = BAR_HEIGHT/(1024.0*128.0); //(COLS_HEIGHT)/1512.0/128.0;
constexpr unsigned long SAMPLING_PERIOD_US = static_cast<unsigned long>(1000000.0 / SAMPLING_FREQUENCY);
constexpr uint16_t USABLE_SAMPLES_COUNT = SAMPLES_COUNT/2 - 1;
unsigned long sampling_time_us;
int sampling_counter;
double vReal[SAMPLES_COUNT];
double vImag[SAMPLES_COUNT];
arduinoFFT FFT = arduinoFFT(vReal, vImag, SAMPLES_COUNT, SAMPLING_FREQUENCY);
double magnitude_bands[BANDS_COUNT];
extern const int bands512[];
void analyser_begin() {
for (int i = 0; i < SAMPLES_COUNT; i++) {
vReal[i] = 0.0;
vImag[i] = 0.0;
}
for (int i = 0; i < BANDS_COUNT; i++)
magnitude_bands[i] = 0.0;
}
void sample_blocking(){
for (int i = 0; i < SAMPLES_COUNT; i++) {
vReal[i] = analogRead(AUDIO_PIN);
vImag[i] = 0;
delayMicroseconds(SAMPLING_PERIOD_US);
}
}
void load_samples(int read_index, volatile int* read_buffer, const int buffersize) {
for (int i = 0; i < SAMPLES_COUNT; i++) {
vReal[i] = read_buffer[read_index--]; //DC removal - 1800
vImag[i] = 0;
if(read_index < 0)
read_index = buffersize-1;
}
}
void calculate_bars() {
FFT.DCRemoval();
FFT.Windowing(FFT_WIN_TYP_HAMMING, FFT_FORWARD);
FFT.Compute(FFT_FORWARD);
FFT.ComplexToMagnitude(); // wynik w vReal
for (int i = 0; i < BANDS_COUNT; i++)
magnitude_bands[i] = 0.0;
for (int i = 1; i < USABLE_SAMPLES_COUNT; i++) {
if (vReal[i] > NOISE_LIMIT)
magnitude_bands[bands512[i]] += vReal[i];
}
for (int i = 0; i < BANDS_COUNT; i++)
magnitude_bands[i] *= BAR_HEIGHT_MODIFIER;
}
double* get_magnitudes() {
return magnitude_bands;
}