Nucleo-F446RE 内蔵の AD/DA を使うためのライブラリ.DA からの出力は,標本化周波数の4倍のレートで行う.AD の読み込みにはソフトウェア割り込みを使用. このライブラリを登録した際のプログラム: Demo_F446_AD_DA_MultirateSWI. Library for built-in ADC and DAC in Nucleo-F446RE using software interrupt for reading ADC. Sampling rate for DAC is four times of that for ADC.
Dependents: F446_UpSampling_LPF_HPF_Variable Demo_F446_AD_DA_MultirateSWI
Biquad.hpp@0:3e5b7187753d, 2018-10-29 (annotated)
- Committer:
- MikamiUitOpen
- Date:
- Mon Oct 29 00:15:06 2018 +0000
- Revision:
- 0:3e5b7187753d
1
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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MikamiUitOpen | 0:3e5b7187753d | 1 | //-------------------------------------------------------------- |
MikamiUitOpen | 0:3e5b7187753d | 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 | 0:3e5b7187753d | 3 | // b0 は 1 と仮定している |
MikamiUitOpen | 0:3e5b7187753d | 4 | // |
MikamiUitOpen | 0:3e5b7187753d | 5 | // 2018/10/11, Copyright (c) 2017 MIKAMI, Naoki |
MikamiUitOpen | 0:3e5b7187753d | 6 | //-------------------------------------------------------------- |
MikamiUitOpen | 0:3e5b7187753d | 7 | |
MikamiUitOpen | 0:3e5b7187753d | 8 | #ifndef IIR_BIQUAD_HPP |
MikamiUitOpen | 0:3e5b7187753d | 9 | #define IIR_BIQUAD_HPP |
MikamiUitOpen | 0:3e5b7187753d | 10 | |
MikamiUitOpen | 0:3e5b7187753d | 11 | #include "mbed.h" |
MikamiUitOpen | 0:3e5b7187753d | 12 | |
MikamiUitOpen | 0:3e5b7187753d | 13 | // 2 次の IIR フィルタ |
MikamiUitOpen | 0:3e5b7187753d | 14 | namespace Mikami |
MikamiUitOpen | 0:3e5b7187753d | 15 | { |
MikamiUitOpen | 0:3e5b7187753d | 16 | class Biquad |
MikamiUitOpen | 0:3e5b7187753d | 17 | { |
MikamiUitOpen | 0:3e5b7187753d | 18 | public: |
MikamiUitOpen | 0:3e5b7187753d | 19 | // フィルタの係数をまとめて扱うための構造体 |
MikamiUitOpen | 0:3e5b7187753d | 20 | struct Coefs { float a1, a2, b1, b2; }; |
MikamiUitOpen | 0:3e5b7187753d | 21 | |
MikamiUitOpen | 0:3e5b7187753d | 22 | // デフォルト・コンストラクタ |
MikamiUitOpen | 0:3e5b7187753d | 23 | // 係数は構造体 Ceofs で与える |
MikamiUitOpen | 0:3e5b7187753d | 24 | Biquad(const Coefs ck = (Coefs){0, 0, 0, 0}) |
MikamiUitOpen | 0:3e5b7187753d | 25 | : a1_(ck.a1), a2_(ck.a2), b1_(ck.b1), b2_(ck.b2) |
MikamiUitOpen | 0:3e5b7187753d | 26 | { Clear(); } |
MikamiUitOpen | 0:3e5b7187753d | 27 | |
MikamiUitOpen | 0:3e5b7187753d | 28 | // 係数を個別に与えるコンストラクタ |
MikamiUitOpen | 0:3e5b7187753d | 29 | Biquad(float a1, float a2, float b1, float b2) |
MikamiUitOpen | 0:3e5b7187753d | 30 | : a1_(a1), a2_(a2), b1_(b1), b2_(b2) |
MikamiUitOpen | 0:3e5b7187753d | 31 | { Clear(); } |
MikamiUitOpen | 0:3e5b7187753d | 32 | |
MikamiUitOpen | 0:3e5b7187753d | 33 | // 2 次のフィルタを実行する |
MikamiUitOpen | 0:3e5b7187753d | 34 | float Execute(float xn) |
MikamiUitOpen | 0:3e5b7187753d | 35 | { |
MikamiUitOpen | 0:3e5b7187753d | 36 | float un = xn + a1_*un1_ + a2_*un2_; |
MikamiUitOpen | 0:3e5b7187753d | 37 | float yn = un + b1_*un1_ + b2_*un2_; |
MikamiUitOpen | 0:3e5b7187753d | 38 | |
MikamiUitOpen | 0:3e5b7187753d | 39 | un2_ = un1_; |
MikamiUitOpen | 0:3e5b7187753d | 40 | un1_ = un; |
MikamiUitOpen | 0:3e5b7187753d | 41 | |
MikamiUitOpen | 0:3e5b7187753d | 42 | return yn; |
MikamiUitOpen | 0:3e5b7187753d | 43 | } |
MikamiUitOpen | 0:3e5b7187753d | 44 | |
MikamiUitOpen | 0:3e5b7187753d | 45 | // 係数を設定する |
MikamiUitOpen | 0:3e5b7187753d | 46 | void SetCoefs(const Coefs ck) |
MikamiUitOpen | 0:3e5b7187753d | 47 | { |
MikamiUitOpen | 0:3e5b7187753d | 48 | a1_ = ck.a1; |
MikamiUitOpen | 0:3e5b7187753d | 49 | a2_ = ck.a2; |
MikamiUitOpen | 0:3e5b7187753d | 50 | b1_ = ck.b1; |
MikamiUitOpen | 0:3e5b7187753d | 51 | b2_ = ck.b2; |
MikamiUitOpen | 0:3e5b7187753d | 52 | } |
MikamiUitOpen | 0:3e5b7187753d | 53 | |
MikamiUitOpen | 0:3e5b7187753d | 54 | // 内部変数(遅延器)のクリア |
MikamiUitOpen | 0:3e5b7187753d | 55 | void Clear() { un1_ = un2_ = 0; } |
MikamiUitOpen | 0:3e5b7187753d | 56 | |
MikamiUitOpen | 0:3e5b7187753d | 57 | private: |
MikamiUitOpen | 0:3e5b7187753d | 58 | float a1_, a2_, b1_, b2_; |
MikamiUitOpen | 0:3e5b7187753d | 59 | float un1_, un2_; |
MikamiUitOpen | 0:3e5b7187753d | 60 | |
MikamiUitOpen | 0:3e5b7187753d | 61 | // コピー・コンストラクタ禁止 |
MikamiUitOpen | 0:3e5b7187753d | 62 | Biquad(const Biquad&); |
MikamiUitOpen | 0:3e5b7187753d | 63 | }; |
MikamiUitOpen | 0:3e5b7187753d | 64 | } |
MikamiUitOpen | 0:3e5b7187753d | 65 | #endif // IIR_BIQUAD_HPP |