boting ren / Mbed 2 deprecated F746_SD_GraphicEqualizer_ren0620

revised version of F746_SD_GraphicEqualizer

Dependencies:   BSP_DISCO_F746NG F746_GUI F746_SAI_IO FrequencyResponseDrawer LCD_DISCO_F746NG SDFileSystem_Warning_Fixed TS_DISCO_F746NG mbed

Fork of F746_SD_GraphicEqualizer by 不韋 呂

MyClasses_Functions/BiquadGrEq.hpp@12:87f6955b5a80, 2016-07-07 (annotated)

Committer:
edamame22
Date:
Thu Jul 07 05:58:52 2016 +0000
Revision:
12:87f6955b5a80
Parent:
0:e953eb392151 
added highlighted line for track selection

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:e953eb392151 1 //--------------------------------------------------------------
MikamiUitOpen 0:e953eb392151 2 // グラフィックイコライザで使う 1D タイプの 2 次のフィルタ
MikamiUitOpen 0:e953eb392151 3 // Biquad filter of 1D type for graphic equalizer
MikamiUitOpen 0:e953eb392151 4 // このクラスでは，係数は実行中に書き換えられることを想定している
MikamiUitOpen 0:e953eb392151 5 //
MikamiUitOpen 0:e953eb392151 6 // u[n] = x[n] + a1*u[n-1] + a2*u[n-2]
MikamiUitOpen 0:e953eb392151 7 // y[n] = b0*u[n] + b1*u[n-1] + b2*u[n-2]
MikamiUitOpen 0:e953eb392151 8 // x[n] : input signal
MikamiUitOpen 0:e953eb392151 9 // y[n] : output signal
MikamiUitOpen 0:e953eb392151 10 //
MikamiUitOpen 0:e953eb392151 11 // 2016/03/25, Copyright (c) 2016 MIKAMI, Naoki
MikamiUitOpen 0:e953eb392151 12 //--------------------------------------------------------------
MikamiUitOpen 0:e953eb392151 13
MikamiUitOpen 0:e953eb392151 14 #ifndef IIR_BIQUAD_HPP
MikamiUitOpen 0:e953eb392151 15 #define IIR_BIQUAD_HPP
MikamiUitOpen 0:e953eb392151 16
MikamiUitOpen 0:e953eb392151 17 #include "mbed.h"
MikamiUitOpen 0:e953eb392151 18
MikamiUitOpen 0:e953eb392151 19 // 2nd order IIR filter
MikamiUitOpen 0:e953eb392151 20 namespace Mikami
MikamiUitOpen 0:e953eb392151 21 {
MikamiUitOpen 0:e953eb392151 22 class BiquadGrEq
MikamiUitOpen 0:e953eb392151 23 {
MikamiUitOpen 0:e953eb392151 24 public:
MikamiUitOpen 0:e953eb392151 25 struct Coefs { float a1, a2, b0, b1, b2; };
MikamiUitOpen 0:e953eb392151 26
MikamiUitOpen 0:e953eb392151 27 BiquadGrEq() {} // Default constructore
MikamiUitOpen 0:e953eb392151 28
MikamiUitOpen 0:e953eb392151 29 BiquadGrEq(const Coefs ck)
MikamiUitOpen 0:e953eb392151 30 {
MikamiUitOpen 0:e953eb392151 31 SetCoefficients(ck);
MikamiUitOpen 0:e953eb392151 32 Clear();
MikamiUitOpen 0:e953eb392151 33 }
MikamiUitOpen 0:e953eb392151 34
MikamiUitOpen 0:e953eb392151 35 void SetCoefficients(const Coefs ck)
MikamiUitOpen 0:e953eb392151 36 {
MikamiUitOpen 0:e953eb392151 37 a1_ = ck.a1;
MikamiUitOpen 0:e953eb392151 38 a2_ = ck.a2;
MikamiUitOpen 0:e953eb392151 39 b0_ = ck.b0;
MikamiUitOpen 0:e953eb392151 40 b1_ = ck.b1;
MikamiUitOpen 0:e953eb392151 41 b2_ = ck.b2;
MikamiUitOpen 0:e953eb392151 42 }
MikamiUitOpen 0:e953eb392151 43
MikamiUitOpen 0:e953eb392151 44 float Execute(float xn)
MikamiUitOpen 0:e953eb392151 45 {
MikamiUitOpen 0:e953eb392151 46 float un = xn + a1_*un1_ + a2_*un2_;
MikamiUitOpen 0:e953eb392151 47 float yn = b0_*un + b1_*un1_ + b2_*un2_;
MikamiUitOpen 0:e953eb392151 48
MikamiUitOpen 0:e953eb392151 49 un2_ = un1_;
MikamiUitOpen 0:e953eb392151 50 un1_ = un;
MikamiUitOpen 0:e953eb392151 51
MikamiUitOpen 0:e953eb392151 52 return yn;
MikamiUitOpen 0:e953eb392151 53 }
MikamiUitOpen 0:e953eb392151 54
MikamiUitOpen 0:e953eb392151 55 void Clear() { un1_ = un2_ = 0; }
MikamiUitOpen 0:e953eb392151 56
MikamiUitOpen 0:e953eb392151 57 private:
MikamiUitOpen 0:e953eb392151 58 float a1_, a2_, b0_, b1_, b2_;
MikamiUitOpen 0:e953eb392151 59 float un1_, un2_;
MikamiUitOpen 0:e953eb392151 60
MikamiUitOpen 0:e953eb392151 61 // disallow copy constructor
MikamiUitOpen 0:e953eb392151 62 BiquadGrEq(const BiquadGrEq&);
MikamiUitOpen 0:e953eb392151 63 };
MikamiUitOpen 0:e953eb392151 64 }
MikamiUitOpen 0:e953eb392151 65 #endif // IIR_BIQUAD_HPP
MikamiUitOpen 0:e953eb392151 66