kopia lustrzana https://github.com/mobilinkd/NucleoTNC
43 wiersze
768 B
C
43 wiersze
768 B
C
#ifndef FILTER_H_
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#define FILTER_H_
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/*
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FIR filter designed with
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http://t-filter.appspot.com
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sampling frequency: 20000 Hz
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* 0 Hz - 800 Hz
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gain = 0
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desired attenuation = -40 dB
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actual attenuation = -40.37597293671087 dB
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* 1100 Hz - 2300 Hz
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gain = 1
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desired ripple = 2 dB
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actual ripple = 1.474114871585135 dB
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* 2600 Hz - 10000 Hz
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gain = 0
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desired attenuation = -40 dB
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actual attenuation = -40.37597293671087 dB
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*/
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#define FILTER_TAP_NUM 31
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extern const float filter_taps[13][FILTER_TAP_NUM];
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typedef struct {
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float taps[FILTER_TAP_NUM];
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float history[FILTER_TAP_NUM];
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unsigned int last_index;
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} Filter;
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void Filter_init(Filter* f, const float* taps);
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void Filter_put(Filter* f, float input);
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float Filter_get(Filter* f);
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#endif
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