不韋 呂 / F446_AD_DA_Multirate

　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． 　このライブラリを登録した際のプログラム： Demo_F446_AD_DA_Multirate. Library for built-in ADC and DAC in Nucleo-F446RE. Sampling rate for DAC is four times of that for ADC.

Dependencies:   Array_Matrix

Dependents:   F446_UpSampling_GraphicEqualizer F446_UpSampling_ReverbSystem F446_UpSampling_FrqShifter_Weaver Demo_F446_AD_DA_Multirate ... more

Biquad.hpp@0:2447a7d225b1, 2018-05-16 (annotated)

Committer:
MikamiUitOpen
Date:
Wed May 16 01:40:50 2018 +0000
Revision:
0:2447a7d225b1
Child:
7:6275fe158ae8
1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:2447a7d225b1 1 //--------------------------------------------------------------
MikamiUitOpen 0:2447a7d225b1 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 0:2447a7d225b1 3 // b0 は 1 と仮定している
MikamiUitOpen 0:2447a7d225b1 4 //
MikamiUitOpen 0:2447a7d225b1 5 // 2018/04/19, Copyright (c) 2017 MIKAMI, Naoki
MikamiUitOpen 0:2447a7d225b1 6 //--------------------------------------------------------------
MikamiUitOpen 0:2447a7d225b1 7
MikamiUitOpen 0:2447a7d225b1 8 #ifndef IIR_BIQUAD_HPP
MikamiUitOpen 0:2447a7d225b1 9 #define IIR_BIQUAD_HPP
MikamiUitOpen 0:2447a7d225b1 10
MikamiUitOpen 0:2447a7d225b1 11 #include "mbed.h"
MikamiUitOpen 0:2447a7d225b1 12
MikamiUitOpen 0:2447a7d225b1 13 // 2 次の IIR フィルタ
MikamiUitOpen 0:2447a7d225b1 14 class Biquad
MikamiUitOpen 0:2447a7d225b1 15 {
MikamiUitOpen 0:2447a7d225b1 16 public:
MikamiUitOpen 0:2447a7d225b1 17 // フィルタの係数をまとめて扱うための構造体
MikamiUitOpen 0:2447a7d225b1 18 struct Coefs { float a1, a2, b1, b2; };
MikamiUitOpen 0:2447a7d225b1 19
MikamiUitOpen 0:2447a7d225b1 20 // デフォルト･コンストラクタ
MikamiUitOpen 0:2447a7d225b1 21 // 係数は構造体 Ceofs で与える
MikamiUitOpen 0:2447a7d225b1 22 Biquad(const Coefs ck = (Coefs){0, 0, 0, 0})
MikamiUitOpen 0:2447a7d225b1 23 : a1_(ck.a1), a2_(ck.a2), b1_(ck.b1), b2_(ck.b2)
MikamiUitOpen 0:2447a7d225b1 24 { Clear(); }
MikamiUitOpen 0:2447a7d225b1 25
MikamiUitOpen 0:2447a7d225b1 26 // 係数を個別に与えるコンストラクタ
MikamiUitOpen 0:2447a7d225b1 27 Biquad(float a1, float a2, float b1, float b2)
MikamiUitOpen 0:2447a7d225b1 28 : a1_(a1), a2_(a2), b1_(b1), b2_(b2)
MikamiUitOpen 0:2447a7d225b1 29 { Clear(); }
MikamiUitOpen 0:2447a7d225b1 30
MikamiUitOpen 0:2447a7d225b1 31 // 2 次のフィルタを実行する
MikamiUitOpen 0:2447a7d225b1 32 float Execute(float xn)
MikamiUitOpen 0:2447a7d225b1 33 {
MikamiUitOpen 0:2447a7d225b1 34 float un = xn + a1_*un1_ + a2_*un2_;
MikamiUitOpen 0:2447a7d225b1 35 float yn = un + b1_*un1_ + b2_*un2_;
MikamiUitOpen 0:2447a7d225b1 36
MikamiUitOpen 0:2447a7d225b1 37 un2_ = un1_;
MikamiUitOpen 0:2447a7d225b1 38 un1_ = un;
MikamiUitOpen 0:2447a7d225b1 39
MikamiUitOpen 0:2447a7d225b1 40 return yn;
MikamiUitOpen 0:2447a7d225b1 41 }
MikamiUitOpen 0:2447a7d225b1 42
MikamiUitOpen 0:2447a7d225b1 43 // 係数を設定する
MikamiUitOpen 0:2447a7d225b1 44 void SetCoefs(const Coefs ck)
MikamiUitOpen 0:2447a7d225b1 45 {
MikamiUitOpen 0:2447a7d225b1 46 a1_ = ck.a1;
MikamiUitOpen 0:2447a7d225b1 47 a2_ = ck.a2;
MikamiUitOpen 0:2447a7d225b1 48 b1_ = ck.b1;
MikamiUitOpen 0:2447a7d225b1 49 b2_ = ck.b2;
MikamiUitOpen 0:2447a7d225b1 50 }
MikamiUitOpen 0:2447a7d225b1 51
MikamiUitOpen 0:2447a7d225b1 52 // 内部変数（遅延器）のクリア
MikamiUitOpen 0:2447a7d225b1 53 void Clear() { un1_ = un2_ = 0; }
MikamiUitOpen 0:2447a7d225b1 54
MikamiUitOpen 0:2447a7d225b1 55 private:
MikamiUitOpen 0:2447a7d225b1 56 float a1_, a2_, b1_, b2_;
MikamiUitOpen 0:2447a7d225b1 57 float un1_, un2_;
MikamiUitOpen 0:2447a7d225b1 58
MikamiUitOpen 0:2447a7d225b1 59 // コピー･コンストラクタ禁止
MikamiUitOpen 0:2447a7d225b1 60 Biquad(const Biquad&);
MikamiUitOpen 0:2447a7d225b1 61 // 代入禁止
MikamiUitOpen 0:2447a7d225b1 62 Biquad& operator=(const Biquad&);
MikamiUitOpen 0:2447a7d225b1 63 };
MikamiUitOpen 0:2447a7d225b1 64
MikamiUitOpen 0:2447a7d225b1 65 #endif // IIR_BIQUAD_HPP