スペクトログラム このプログラムの説明は,CQ出版社「トランジスタ技術」の2021年10月号から開始された連載記事「STM32マイコンではじめるPC計測」の中にあります.このプログラムといっしょに使うPC側のプログラムについても同誌を参照してください.

Dependencies:   Array_Matrix mbed SerialTxRxIntr DSP_ADDA UIT_FFT_Real Window

Committer:
MikamiUitOpen
Date:
Thu Sep 09 08:55:42 2021 +0000
Revision:
0:3bf11d2ab6ad
1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:3bf11d2ab6ad 1 //--------------------------------------------------------------
MikamiUitOpen 0:3bf11d2ab6ad 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 0:3bf11d2ab6ad 3 // b0 は 1 と仮定している
MikamiUitOpen 0:3bf11d2ab6ad 4 //
MikamiUitOpen 0:3bf11d2ab6ad 5 // 2020/11/04, Copyright (c) 2020 MIKAMI, Naoki
MikamiUitOpen 0:3bf11d2ab6ad 6 //--------------------------------------------------------------
MikamiUitOpen 0:3bf11d2ab6ad 7
MikamiUitOpen 0:3bf11d2ab6ad 8 #include "mbed.h"
MikamiUitOpen 0:3bf11d2ab6ad 9
MikamiUitOpen 0:3bf11d2ab6ad 10 #ifndef IIR_BIQUAD_HPP
MikamiUitOpen 0:3bf11d2ab6ad 11 #define IIR_BIQUAD_HPP
MikamiUitOpen 0:3bf11d2ab6ad 12
MikamiUitOpen 0:3bf11d2ab6ad 13 class Biquad
MikamiUitOpen 0:3bf11d2ab6ad 14 {
MikamiUitOpen 0:3bf11d2ab6ad 15 public:
MikamiUitOpen 0:3bf11d2ab6ad 16 // フィルタの係数をまとめて扱うための構造体
MikamiUitOpen 0:3bf11d2ab6ad 17 struct Coefs { float a1, a2, b1, b2; };
MikamiUitOpen 0:3bf11d2ab6ad 18
MikamiUitOpen 0:3bf11d2ab6ad 19 // デフォルト・コンストラクタ
MikamiUitOpen 0:3bf11d2ab6ad 20 // 係数は構造体 Ceofs で与える
MikamiUitOpen 0:3bf11d2ab6ad 21 Biquad(const Coefs ck = (Coefs){0, 0, 0, 0})
MikamiUitOpen 0:3bf11d2ab6ad 22 : a1_(ck.a1), a2_(ck.a2), b1_(ck.b1), b2_(ck.b2),
MikamiUitOpen 0:3bf11d2ab6ad 23 un1_(0), un2_(0) {}
MikamiUitOpen 0:3bf11d2ab6ad 24
MikamiUitOpen 0:3bf11d2ab6ad 25 // 係数を個別に与えるコンストラクタ
MikamiUitOpen 0:3bf11d2ab6ad 26 Biquad(float a1, float a2, float b1, float b2)
MikamiUitOpen 0:3bf11d2ab6ad 27 : a1_(a1), a2_(a2), b1_(b1), b2_(b2), un1_(0), un2_(0) {}
MikamiUitOpen 0:3bf11d2ab6ad 28
MikamiUitOpen 0:3bf11d2ab6ad 29 virtual ~Biquad() {}
MikamiUitOpen 0:3bf11d2ab6ad 30
MikamiUitOpen 0:3bf11d2ab6ad 31 // 2 次のフィルタを実行する
MikamiUitOpen 0:3bf11d2ab6ad 32 float Execute(float xn)
MikamiUitOpen 0:3bf11d2ab6ad 33 {
MikamiUitOpen 0:3bf11d2ab6ad 34 float un = xn + a1_*un1_ + a2_*un2_;
MikamiUitOpen 0:3bf11d2ab6ad 35 float yn = un + b1_*un1_ + b2_*un2_;
MikamiUitOpen 0:3bf11d2ab6ad 36
MikamiUitOpen 0:3bf11d2ab6ad 37 un2_ = un1_;
MikamiUitOpen 0:3bf11d2ab6ad 38 un1_ = un;
MikamiUitOpen 0:3bf11d2ab6ad 39
MikamiUitOpen 0:3bf11d2ab6ad 40 return yn;
MikamiUitOpen 0:3bf11d2ab6ad 41 }
MikamiUitOpen 0:3bf11d2ab6ad 42
MikamiUitOpen 0:3bf11d2ab6ad 43 // 係数を設定する
MikamiUitOpen 0:3bf11d2ab6ad 44 void SetCoefs(const Coefs ck)
MikamiUitOpen 0:3bf11d2ab6ad 45 {
MikamiUitOpen 0:3bf11d2ab6ad 46 a1_ = ck.a1;
MikamiUitOpen 0:3bf11d2ab6ad 47 a2_ = ck.a2;
MikamiUitOpen 0:3bf11d2ab6ad 48 b1_ = ck.b1;
MikamiUitOpen 0:3bf11d2ab6ad 49 b2_ = ck.b2;
MikamiUitOpen 0:3bf11d2ab6ad 50 }
MikamiUitOpen 0:3bf11d2ab6ad 51
MikamiUitOpen 0:3bf11d2ab6ad 52 // 内部変数(遅延器)のクリア
MikamiUitOpen 0:3bf11d2ab6ad 53 void Clear() { un1_ = un2_ = 0; }
MikamiUitOpen 0:3bf11d2ab6ad 54
MikamiUitOpen 0:3bf11d2ab6ad 55 private:
MikamiUitOpen 0:3bf11d2ab6ad 56 float a1_, a2_, b1_, b2_; // フィルタの係数
MikamiUitOpen 0:3bf11d2ab6ad 57 float un1_, un2_; // 遅延器
MikamiUitOpen 0:3bf11d2ab6ad 58
MikamiUitOpen 0:3bf11d2ab6ad 59 // コピー・コンストラクタ禁止
MikamiUitOpen 0:3bf11d2ab6ad 60 Biquad(const Biquad&);
MikamiUitOpen 0:3bf11d2ab6ad 61 };
MikamiUitOpen 0:3bf11d2ab6ad 62 #endif // IIR_BIQUAD_HPP