kopia lustrzana https://github.com/kosme/arduinoFFT
116 wiersze
3.8 KiB
C++
116 wiersze
3.8 KiB
C++
/*
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FFT library
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Copyright (C) 2010 Didier Longueville
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Copyright (C) 2014 Enrique Condes
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef arduinoFFT_h /* Prevent loading library twice */
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#define arduinoFFT_h
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#ifdef ARDUINO
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#if ARDUINO >= 100
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#include "Arduino.h"
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#else
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#include "WProgram.h" /* This is where the standard Arduino code lies */
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#endif
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#else
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#include <stdlib.h>
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#include <stdio.h>
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#ifdef __AVR__
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#include <avr/io.h>
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#include <avr/pgmspace.h>
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#endif
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#include <math.h>
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#include "defs.h"
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#include "types.h"
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#endif
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#define FFT_LIB_REV 0x14
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/* Custom constants */
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#define FFT_FORWARD 0x01
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#define FFT_REVERSE 0x00
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/* Windowing type */
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#define FFT_WIN_TYP_RECTANGLE 0x00 /* rectangle (Box car) */
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#define FFT_WIN_TYP_HAMMING 0x01 /* hamming */
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#define FFT_WIN_TYP_HANN 0x02 /* hann */
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#define FFT_WIN_TYP_TRIANGLE 0x03 /* triangle (Bartlett) */
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#define FFT_WIN_TYP_NUTTALL 0x04 /* nuttall */
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#define FFT_WIN_TYP_BLACKMAN 0x05 /* blackman */
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#define FFT_WIN_TYP_BLACKMAN_NUTTALL 0x06 /* blackman nuttall */
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#define FFT_WIN_TYP_BLACKMAN_HARRIS 0x07 /* blackman harris*/
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#define FFT_WIN_TYP_FLT_TOP 0x08 /* flat top */
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#define FFT_WIN_TYP_WELCH 0x09 /* welch */
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/*Mathematial constants*/
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#define twoPi 6.28318531
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#define fourPi 12.56637061
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#define sixPi 18.84955593
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#ifdef __AVR__
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static const double _c1[]PROGMEM = {0.0000000000, 0.7071067812, 0.9238795325, 0.9807852804,
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0.9951847267, 0.9987954562, 0.9996988187, 0.9999247018,
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0.9999811753, 0.9999952938, 0.9999988235, 0.9999997059,
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0.9999999265, 0.9999999816, 0.9999999954, 0.9999999989,
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0.9999999997};
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static const double _c2[]PROGMEM = {1.0000000000, 0.7071067812, 0.3826834324, 0.1950903220,
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0.0980171403, 0.0490676743, 0.0245412285, 0.0122715383,
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0.0061358846, 0.0030679568, 0.0015339802, 0.0007669903,
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0.0003834952, 0.0001917476, 0.0000958738, 0.0000479369,
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0.0000239684};
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#endif
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class arduinoFFT {
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public:
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/* Constructor */
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arduinoFFT(void);
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arduinoFFT(double *vReal, double *vImag, uint16_t samples, double samplingFrequency);
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/* Destructor */
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~arduinoFFT(void);
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/* Functions */
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uint8_t Revision(void);
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uint8_t Exponent(uint16_t value);
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void ComplexToMagnitude(double *vReal, double *vImag, uint16_t samples);
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void Compute(double *vReal, double *vImag, uint16_t samples, uint8_t dir);
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void Compute(double *vReal, double *vImag, uint16_t samples, uint8_t power, uint8_t dir);
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void DCRemoval(double *vData, uint16_t samples);
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double MajorPeak(double *vD, uint16_t samples, double samplingFrequency);
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void MajorPeak(double *vD, uint16_t samples, double samplingFrequency, double *f, double *v);
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void Windowing(double *vData, uint16_t samples, uint8_t windowType, uint8_t dir);
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void ComplexToMagnitude();
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void Compute(uint8_t dir);
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void DCRemoval();
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double MajorPeak();
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void MajorPeak(double *f, double *v);
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void Windowing(uint8_t windowType, uint8_t dir);
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double MajorPeakParabola();
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private:
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/* Variables */
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uint16_t _samples;
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double _samplingFrequency;
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double *_vReal;
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double *_vImag;
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uint8_t _power;
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/* Functions */
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void Swap(double *x, double *y);
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void Parabola(double x1, double y1, double x2, double y2, double x3, double y3, double *a, double *b, double *c);
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};
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#endif
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