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?
User | Revision | Line number | New 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 |