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
MyClasses_Functions/BiquadGrEq.hpp
- Committer:
- edamame22
- Date:
- 2016-07-07
- Revision:
- 12:87f6955b5a80
- Parent:
- 0:e953eb392151
File content as of revision 12:87f6955b5a80:
//-------------------------------------------------------------- // 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 // Biquad filter of 1D type for graphic equalizer // 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 // // u[n] = x[n] + a1*u[n-1] + a2*u[n-2] // y[n] = b0*u[n] + b1*u[n-1] + b2*u[n-2] // x[n] : input signal // y[n] : output signal // // 2016/03/25, Copyright (c) 2016 MIKAMI, Naoki //-------------------------------------------------------------- #ifndef IIR_BIQUAD_HPP #define IIR_BIQUAD_HPP #include "mbed.h" // 2nd order IIR filter namespace Mikami { class BiquadGrEq { public: struct Coefs { float a1, a2, b0, b1, b2; }; BiquadGrEq() {} // Default constructore BiquadGrEq(const Coefs ck) { SetCoefficients(ck); Clear(); } void SetCoefficients(const Coefs ck) { a1_ = ck.a1; a2_ = ck.a2; b0_ = ck.b0; b1_ = ck.b1; b2_ = ck.b2; } float Execute(float xn) { float un = xn + a1_*un1_ + a2_*un2_; float yn = b0_*un + b1_*un1_ + b2_*un2_; un2_ = un1_; un1_ = un; return yn; } void Clear() { un1_ = un2_ = 0; } private: float a1_, a2_, b0_, b1_, b2_; float un1_, un2_; // disallow copy constructor BiquadGrEq(const BiquadGrEq&); }; } #endif // IIR_BIQUAD_HPP