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phase_t

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This commit is contained in:
Sébastien Bourdeauducq 2024-12-31 17:04:37 +08:00
parent 4306a234b9
commit 5991fa600d
1 changed files with 11 additions and 8 deletions
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19
dsp_lib.h
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@ -3,18 +3,21 @@
#include <cstdint>
#include <complex>
static uint32_t frequency_to_ftw(double f) {
return f*(double)UINT32_MAX;
typedef uint32_t phase_t;
#define PHASE_MAX UINT32_MAX
static phase_t frequency_to_ftw(double f) {
return f*(double)PHASE_MAX;
}
class DDS {
private:
uint32_t phase = 0;
phase_t phase = 0;
public:
uint32_t ftw = 0;
phase_t ftw = 0;
double get() {
phase += ftw; // wraps on overflow
return sin(phase*2.0*M_PI/(double)UINT32_MAX);
return sin(phase*2.0*M_PI/(double)PHASE_MAX);
}
};
@ -41,10 +44,10 @@ template<unsigned int order>
class Lockin {
private:
double scale;
uint32_t phase = 0;
phase_t phase = 0;
Lowpass<std::complex<double>, order> lpf;
public:
uint32_t ftw = 0;
phase_t ftw = 0;
void set_scale(double s) {
scale = s;
}
@ -53,7 +56,7 @@ class Lockin {
}
std::complex<double> update(double x) {
std::complex<double> rotated;
rotated = x*std::polar(scale, phase*2.0*M_PI/(double)UINT32_MAX);
rotated = x*std::polar(scale, phase*2.0*M_PI/(double)PHASE_MAX);
phase -= ftw; // wraps on underflow
return lpf.update(rotated);
}