不韋 呂 / Mbed 2 deprecated DSP_VariableLHpfB

CQエレクトロニクス・セミナで使用する遮断周波数可変の LPF/HPF のプログラム

Dependencies:   mbed SerialTxRxIntr DSP_MultirateLinearphase

IirVariable/Biquad.hpp@2:3955cb401851, 2022-03-30 (annotated)

Committer:
MikamiUitOpen
Date:
Wed Mar 30 05:00:14 2022 +0000
Revision:
2:3955cb401851
Parent:
0:f1e2a221b526 
3

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:f1e2a221b526 1 //--------------------------------------------------------------
MikamiUitOpen 0:f1e2a221b526 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:f1e2a221b526 3 // b0 は 1 と仮定している
MikamiUitOpen 0:f1e2a221b526 4 //
MikamiUitOpen 0:f1e2a221b526 5 // 2022/02/19, Copyright (c) 2022 MIKAMI, Naoki
MikamiUitOpen 0:f1e2a221b526 6 //--------------------------------------------------------------
MikamiUitOpen 0:f1e2a221b526 7
MikamiUitOpen 0:f1e2a221b526 8 #ifndef IIR_BIQUAD_HPP
MikamiUitOpen 0:f1e2a221b526 9 #define IIR_BIQUAD_HPP
MikamiUitOpen 0:f1e2a221b526 10
MikamiUitOpen 0:f1e2a221b526 11 #include "mbed.h"
MikamiUitOpen 0:f1e2a221b526 12
MikamiUitOpen 0:f1e2a221b526 13 namespace Mikami
MikamiUitOpen 0:f1e2a221b526 14 {
MikamiUitOpen 0:f1e2a221b526 15 class Biquad
MikamiUitOpen 0:f1e2a221b526 16 {
MikamiUitOpen 0:f1e2a221b526 17 public:
MikamiUitOpen 0:f1e2a221b526 18 // フィルタの係数をまとめて扱うための構造体
MikamiUitOpen 0:f1e2a221b526 19 struct Coefs { float a1, a2, b1, b2; };
MikamiUitOpen 0:f1e2a221b526 20
MikamiUitOpen 0:f1e2a221b526 21 // デフォルト･コンストラクタ
MikamiUitOpen 0:f1e2a221b526 22 // 係数は構造体 Ceofs で与える
MikamiUitOpen 0:f1e2a221b526 23 Biquad(const Coefs ck = (Coefs){0, 0, 0, 0})
MikamiUitOpen 0:f1e2a221b526 24 : c_(ck), vn1_(0), vn2_(0) {}
MikamiUitOpen 0:f1e2a221b526 25
MikamiUitOpen 0:f1e2a221b526 26 // 2 次のフィルタを実行する
MikamiUitOpen 0:f1e2a221b526 27 float Execute(float xn)
MikamiUitOpen 0:f1e2a221b526 28 {
MikamiUitOpen 0:f1e2a221b526 29 float vn = xn + c_.a1*vn1_ + c_.a2*vn2_;
MikamiUitOpen 0:f1e2a221b526 30 float yn = vn + c_.b1*vn1_ + c_.b2*vn2_;
MikamiUitOpen 0:f1e2a221b526 31
MikamiUitOpen 0:f1e2a221b526 32 vn2_ = vn1_;
MikamiUitOpen 0:f1e2a221b526 33 vn1_ = vn;
MikamiUitOpen 0:f1e2a221b526 34
MikamiUitOpen 0:f1e2a221b526 35 return yn;
MikamiUitOpen 0:f1e2a221b526 36 }
MikamiUitOpen 0:f1e2a221b526 37
MikamiUitOpen 0:f1e2a221b526 38 // 係数を設定する
MikamiUitOpen 0:f1e2a221b526 39 void SetCoefs(const Coefs ck) { c_ = ck; }
MikamiUitOpen 0:f1e2a221b526 40
MikamiUitOpen 0:f1e2a221b526 41 // 内部変数（遅延器）のクリア
MikamiUitOpen 0:f1e2a221b526 42 void Clear() { vn1_ = vn2_ = 0; }
MikamiUitOpen 0:f1e2a221b526 43
MikamiUitOpen 0:f1e2a221b526 44 private:
MikamiUitOpen 0:f1e2a221b526 45 Coefs c_;
MikamiUitOpen 0:f1e2a221b526 46 float vn1_, vn2_;
MikamiUitOpen 0:f1e2a221b526 47
MikamiUitOpen 0:f1e2a221b526 48 // コピー･コンストラクタ禁止のため
MikamiUitOpen 0:f1e2a221b526 49 Biquad(const Biquad&);
MikamiUitOpen 0:f1e2a221b526 50 };
MikamiUitOpen 0:f1e2a221b526 51 }
MikamiUitOpen 0:f1e2a221b526 52 #endif // IIR_BIQUAD_HPP