不韋 呂 / Mbed 2 deprecated F446_DSP_FFT_Analyzer

FFT によるスペクトル解析器

Dependencies:   Array_Matrix mbed SerialTxRxIntr UIT_FFT_Real DSP_ADDA

IIR_Filter/Biquad.hpp@0:91cc5a03f0ca, 2021-01-08 (annotated)

Committer:
MikamiUitOpen
Date:
Fri Jan 08 02:27:46 2021 +0000
Revision:
0:91cc5a03f0ca
1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:91cc5a03f0ca 1 //--------------------------------------------------------------
MikamiUitOpen 0:91cc5a03f0ca 2 // 縦続形 IIR フィルタの構成要素として使う 2 次の IIR フィルタ
MikamiUitOpen 0:91cc5a03f0ca 3 // b0 は 1 と仮定している
MikamiUitOpen 0:91cc5a03f0ca 4 //
MikamiUitOpen 0:91cc5a03f0ca 5 // 2020/11/04, Copyright (c) 2020 MIKAMI, Naoki
MikamiUitOpen 0:91cc5a03f0ca 6 //--------------------------------------------------------------
MikamiUitOpen 0:91cc5a03f0ca 7
MikamiUitOpen 0:91cc5a03f0ca 8 #include "mbed.h"
MikamiUitOpen 0:91cc5a03f0ca 9
MikamiUitOpen 0:91cc5a03f0ca 10 #ifndef IIR_BIQUAD_HPP
MikamiUitOpen 0:91cc5a03f0ca 11 #define IIR_BIQUAD_HPP
MikamiUitOpen 0:91cc5a03f0ca 12
MikamiUitOpen 0:91cc5a03f0ca 13 class Biquad
MikamiUitOpen 0:91cc5a03f0ca 14 {
MikamiUitOpen 0:91cc5a03f0ca 15 public:
MikamiUitOpen 0:91cc5a03f0ca 16 // フィルタの係数をまとめて扱うための構造体
MikamiUitOpen 0:91cc5a03f0ca 17 struct Coefs { float a1, a2, b1, b2; };
MikamiUitOpen 0:91cc5a03f0ca 18
MikamiUitOpen 0:91cc5a03f0ca 19 // デフォルト･コンストラクタ
MikamiUitOpen 0:91cc5a03f0ca 20 // 係数は構造体 Ceofs で与える
MikamiUitOpen 0:91cc5a03f0ca 21 Biquad(const Coefs ck = (Coefs){0, 0, 0, 0})
MikamiUitOpen 0:91cc5a03f0ca 22 : a1_(ck.a1), a2_(ck.a2), b1_(ck.b1), b2_(ck.b2),
MikamiUitOpen 0:91cc5a03f0ca 23 un1_(0), un2_(0) {}
MikamiUitOpen 0:91cc5a03f0ca 24
MikamiUitOpen 0:91cc5a03f0ca 25 // 係数を個別に与えるコンストラクタ
MikamiUitOpen 0:91cc5a03f0ca 26 Biquad(float a1, float a2, float b1, float b2)
MikamiUitOpen 0:91cc5a03f0ca 27 : a1_(a1), a2_(a2), b1_(b1), b2_(b2), un1_(0), un2_(0) {}
MikamiUitOpen 0:91cc5a03f0ca 28
MikamiUitOpen 0:91cc5a03f0ca 29 virtual ~Biquad() {}
MikamiUitOpen 0:91cc5a03f0ca 30
MikamiUitOpen 0:91cc5a03f0ca 31 // 2 次のフィルタを実行する
MikamiUitOpen 0:91cc5a03f0ca 32 float Execute(float xn)
MikamiUitOpen 0:91cc5a03f0ca 33 {
MikamiUitOpen 0:91cc5a03f0ca 34 float un = xn + a1_*un1_ + a2_*un2_;
MikamiUitOpen 0:91cc5a03f0ca 35 float yn = un + b1_*un1_ + b2_*un2_;
MikamiUitOpen 0:91cc5a03f0ca 36
MikamiUitOpen 0:91cc5a03f0ca 37 un2_ = un1_;
MikamiUitOpen 0:91cc5a03f0ca 38 un1_ = un;
MikamiUitOpen 0:91cc5a03f0ca 39
MikamiUitOpen 0:91cc5a03f0ca 40 return yn;
MikamiUitOpen 0:91cc5a03f0ca 41 }
MikamiUitOpen 0:91cc5a03f0ca 42
MikamiUitOpen 0:91cc5a03f0ca 43 // 係数を設定する
MikamiUitOpen 0:91cc5a03f0ca 44 void SetCoefs(const Coefs ck)
MikamiUitOpen 0:91cc5a03f0ca 45 {
MikamiUitOpen 0:91cc5a03f0ca 46 a1_ = ck.a1;
MikamiUitOpen 0:91cc5a03f0ca 47 a2_ = ck.a2;
MikamiUitOpen 0:91cc5a03f0ca 48 b1_ = ck.b1;
MikamiUitOpen 0:91cc5a03f0ca 49 b2_ = ck.b2;
MikamiUitOpen 0:91cc5a03f0ca 50 }
MikamiUitOpen 0:91cc5a03f0ca 51
MikamiUitOpen 0:91cc5a03f0ca 52 // 内部変数（遅延器）のクリア
MikamiUitOpen 0:91cc5a03f0ca 53 void Clear() { un1_ = un2_ = 0; }
MikamiUitOpen 0:91cc5a03f0ca 54
MikamiUitOpen 0:91cc5a03f0ca 55 private:
MikamiUitOpen 0:91cc5a03f0ca 56 float a1_, a2_, b1_, b2_; // フィルタの係数
MikamiUitOpen 0:91cc5a03f0ca 57 float un1_, un2_; // 遅延器
MikamiUitOpen 0:91cc5a03f0ca 58
MikamiUitOpen 0:91cc5a03f0ca 59 // コピー･コンストラクタ禁止
MikamiUitOpen 0:91cc5a03f0ca 60 Biquad(const Biquad&);
MikamiUitOpen 0:91cc5a03f0ca 61 };
MikamiUitOpen 0:91cc5a03f0ca 62 #endif // IIR_BIQUAD_HPP