Cutoff frequency variable LPF by IIR 6th-order Butterworth filter for ST Nucleo F401RE.
Dependencies: UIT_IIR_Filter UIT_ACM1602NI UITDSP_ADDA mbed UIT_AQM1602
Biquad.hpp
- Committer:
- MikamiUitOpen
- Date:
- 2015-07-25
- Revision:
- 6:116f72cda0f4
- Parent:
- 0:a9412b9e85b7
File content as of revision 6:116f72cda0f4:
//-------------------------------------------------------------- // Biquad filter for IIR filter of cascade structure // 2014/10/21, Copyright (c) 2014 MIKAMI, Naoki //-------------------------------------------------------------- #ifndef IIR_BIQUAD_HPP #define IIR_BIQUAD_HPP #include "mbed.h" // 2nd order IIR filter class Biquad { public: struct Coefs { float a1, a2, b1, b2; }; Biquad() {} // Default constructore Biquad(const Coefs ck) : a1_(ck.a1), a2_(ck.a2), b1_(ck.b1), b2_(ck.b2) { Clear(); } float Execute(float xn) { float un = xn + a1_*un1_ + a2_*un2_; float yn = un + b1_*un1_ + b2_*un2_; un2_ = un1_; un1_ = un; return yn; } void Clear() { un1_ = un2_ = 0; } private: float a1_, a2_, b1_, b2_; float un1_, un2_; Biquad(const Biquad&); }; #endif // IIR_BIQUAD_HPP