不韋 呂 / Mbed 2 deprecated UIT2_IIR_Cascade_Biquad

IIR filter of cascade form using Biquad class for ST Nucleo F401RE.

Dependencies:   UITDSP_ADDA mbed

main.cpp@7:ee6c82112718, 2015-09-04 (annotated)

Committer:
MikamiUitOpen
Date:
Fri Sep 04 09:07:38 2015 +0000
Revision:
7:ee6c82112718
Parent:
5:14bb865c7eee 
8

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:24c904911225 1 //--------------------------------------------------------------
MikamiUitOpen 0:24c904911225 2 // IIR フィルタ，縦続形，float で演算, Biquad クラス利用
MikamiUitOpen 0:24c904911225 3 // Analog Input : A0
MikamiUitOpen 0:24c904911225 4 // Analog Output: MCP4922 using SPI
MikamiUitOpen 7:ee6c82112718 5 // 2015/07/03, Copyright (c) 2015 MIKAMI, Naoki
MikamiUitOpen 0:24c904911225 6 //--------------------------------------------------------------
MikamiUitOpen 0:24c904911225 7
MikamiUitOpen 7:ee6c82112718 8 #include "ADC_BuiltIn.hpp" // for ADC not using interrupt
MikamiUitOpen 7:ee6c82112718 9 #include "DAC_MCP4921.hpp" // for DAC MCP4921, MCP4922
MikamiUitOpen 0:24c904911225 10 #include "Biquad.hpp" // 2nd-ordered IIR filter
MikamiUitOpen 0:24c904911225 11
MikamiUitOpen 0:24c904911225 12 using namespace Mikami;
MikamiUitOpen 0:24c904911225 13
MikamiUitOpen 0:24c904911225 14 const int ORDER_ = 6; // order
MikamiUitOpen 0:24c904911225 15
MikamiUitOpen 0:24c904911225 16 // 低域通過フィルタ
MikamiUitOpen 0:24c904911225 17 // 連立チェビシェフ特性
MikamiUitOpen 0:24c904911225 18 // 次数　　　　：6 次
MikamiUitOpen 0:24c904911225 19 // 標本化周波数： 12.00 kHz
MikamiUitOpen 0:24c904911225 20 // 遮断周波数　： 0.40 kHz
MikamiUitOpen 0:24c904911225 21 // 通過域のリップル： 0.50 dB
MikamiUitOpen 0:24c904911225 22 // 阻止域の減衰量　：40.00 dB
MikamiUitOpen 0:24c904911225 23 const Biquad::Coefs ck_[ORDER_/2] = {
MikamiUitOpen 1:ec14a181cab8 24 { 1.837790E+00f, -8.507293E-01f, -1.603320E+00f, 1.0E+00f}, // 1段目
MikamiUitOpen 1:ec14a181cab8 25 { 1.904445E+00f, -9.382561E-01f, -1.919647E+00f, 1.0E+00f}, // 2段目
MikamiUitOpen 1:ec14a181cab8 26 { 1.942552E+00f, -9.865720E-01f, -1.942961E+00f, 1.0E+00f}}; // 3段目
MikamiUitOpen 0:24c904911225 27 const float g0_ = 1.000028E-02f; // 利得定数
MikamiUitOpen 0:24c904911225 28
MikamiUitOpen 7:ee6c82112718 29 const int FS_ = 12000; // Sampling frequency: 12 kHz
MikamiUitOpen 7:ee6c82112718 30 ADC_BuiltIn adc_(A0, FS_); // for AD
MikamiUitOpen 7:ee6c82112718 31 DAC_MCP4921 myDac_; // for DA
MikamiUitOpen 0:24c904911225 32
MikamiUitOpen 0:24c904911225 33 int main()
MikamiUitOpen 0:24c904911225 34 {
MikamiUitOpen 5:14bb865c7eee 35 myDac_.ScfClockTim3(500000); // cutoff frequency: 5 kHz
MikamiUitOpen 0:24c904911225 36
MikamiUitOpen 0:24c904911225 37 Biquad hn[ORDER_/2];
MikamiUitOpen 0:24c904911225 38 for (int k=0; k<ORDER_/2; k++)
MikamiUitOpen 0:24c904911225 39 hn[k] = Biquad(ck_[k]);
MikamiUitOpen 0:24c904911225 40
MikamiUitOpen 0:24c904911225 41 while (true)
MikamiUitOpen 0:24c904911225 42 {
MikamiUitOpen 0:24c904911225 43 float xn = adc_.Read(); // Read from A0
MikamiUitOpen 0:24c904911225 44 //-----------------------------------------------
MikamiUitOpen 0:24c904911225 45
MikamiUitOpen 0:24c904911225 46 float yn = g0_*xn;
MikamiUitOpen 0:24c904911225 47 for (int k=0; k<ORDER_/2; k++)
MikamiUitOpen 0:24c904911225 48 yn = hn[k].Execute(yn);
MikamiUitOpen 0:24c904911225 49
MikamiUitOpen 0:24c904911225 50 //-----------------------------------------------
MikamiUitOpen 0:24c904911225 51 myDac_.Write(yn); // Write to DAC
MikamiUitOpen 0:24c904911225 52 }
MikamiUitOpen 0:24c904911225 53 }
MikamiUitOpen 0:24c904911225 54
MikamiUitOpen 0:24c904911225 55