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@7:6275fe158ae8, 2018-10-11 (annotated)

Committer:
MikamiUitOpen
Date:
Thu Oct 11 11:42:48 2018 +0000
Revision:
7:6275fe158ae8
Parent:
0:2447a7d225b1 
8

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 7:6275fe158ae8 5 // 2018/10/11, 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 7:6275fe158ae8 14 namespace Mikami
MikamiUitOpen 0:2447a7d225b1 15 {
MikamiUitOpen 7:6275fe158ae8 16 class Biquad
MikamiUitOpen 7:6275fe158ae8 17 {
MikamiUitOpen 7:6275fe158ae8 18 public:
MikamiUitOpen 7:6275fe158ae8 19 // フィルタの係数をまとめて扱うための構造体
MikamiUitOpen 7:6275fe158ae8 20 struct Coefs { float a1, a2, b1, b2; };
MikamiUitOpen 0:2447a7d225b1 21
MikamiUitOpen 7:6275fe158ae8 22 // デフォルト･コンストラクタ
MikamiUitOpen 7:6275fe158ae8 23 // 係数は構造体 Ceofs で与える
MikamiUitOpen 7:6275fe158ae8 24 Biquad(const Coefs ck = (Coefs){0, 0, 0, 0})
MikamiUitOpen 7:6275fe158ae8 25 : a1_(ck.a1), a2_(ck.a2), b1_(ck.b1), b2_(ck.b2)
MikamiUitOpen 7:6275fe158ae8 26 { Clear(); }
MikamiUitOpen 0:2447a7d225b1 27
MikamiUitOpen 7:6275fe158ae8 28 // 係数を個別に与えるコンストラクタ
MikamiUitOpen 7:6275fe158ae8 29 Biquad(float a1, float a2, float b1, float b2)
MikamiUitOpen 7:6275fe158ae8 30 : a1_(a1), a2_(a2), b1_(b1), b2_(b2)
MikamiUitOpen 7:6275fe158ae8 31 { Clear(); }
MikamiUitOpen 7:6275fe158ae8 32
MikamiUitOpen 7:6275fe158ae8 33 // 2 次のフィルタを実行する
MikamiUitOpen 7:6275fe158ae8 34 float Execute(float xn)
MikamiUitOpen 7:6275fe158ae8 35 {
MikamiUitOpen 7:6275fe158ae8 36 float un = xn + a1_*un1_ + a2_*un2_;
MikamiUitOpen 7:6275fe158ae8 37 float yn = un + b1_*un1_ + b2_*un2_;
MikamiUitOpen 0:2447a7d225b1 38
MikamiUitOpen 7:6275fe158ae8 39 un2_ = un1_;
MikamiUitOpen 7:6275fe158ae8 40 un1_ = un;
MikamiUitOpen 7:6275fe158ae8 41
MikamiUitOpen 7:6275fe158ae8 42 return yn;
MikamiUitOpen 7:6275fe158ae8 43 }
MikamiUitOpen 0:2447a7d225b1 44
MikamiUitOpen 7:6275fe158ae8 45 // 係数を設定する
MikamiUitOpen 7:6275fe158ae8 46 void SetCoefs(const Coefs ck)
MikamiUitOpen 7:6275fe158ae8 47 {
MikamiUitOpen 7:6275fe158ae8 48 a1_ = ck.a1;
MikamiUitOpen 7:6275fe158ae8 49 a2_ = ck.a2;
MikamiUitOpen 7:6275fe158ae8 50 b1_ = ck.b1;
MikamiUitOpen 7:6275fe158ae8 51 b2_ = ck.b2;
MikamiUitOpen 7:6275fe158ae8 52 }
MikamiUitOpen 0:2447a7d225b1 53
MikamiUitOpen 7:6275fe158ae8 54 // 内部変数（遅延器）のクリア
MikamiUitOpen 7:6275fe158ae8 55 void Clear() { un1_ = un2_ = 0; }
MikamiUitOpen 0:2447a7d225b1 56
MikamiUitOpen 7:6275fe158ae8 57 private:
MikamiUitOpen 7:6275fe158ae8 58 float a1_, a2_, b1_, b2_;
MikamiUitOpen 7:6275fe158ae8 59 float un1_, un2_;
MikamiUitOpen 7:6275fe158ae8 60
MikamiUitOpen 7:6275fe158ae8 61 // コピー･コンストラクタ禁止
MikamiUitOpen 7:6275fe158ae8 62 Biquad(const Biquad&);
MikamiUitOpen 7:6275fe158ae8 63 };
MikamiUitOpen 7:6275fe158ae8 64 }
MikamiUitOpen 0:2447a7d225b1 65 #endif // IIR_BIQUAD_HPP