不韋 呂 / Mbed 2 deprecated UIT2_Dualphase_Oscillator

Dual-phase oscillator using 2nd-order IIR filter.

Dependencies:   UITDSP_ADDA mbed

Files at this revision

API Documentation at this revision

Revision 1:60bb239847c3, committed 2016-02-23

Comitter:
MikamiUitOpen
Date:
Tue Feb 23 00:28:02 2016 +0000
Parent:
0:45f7919cc254
Commit message:
2

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file 
--- a/main.cpp	Tue Feb 16 06:50:27 2016 +0000
+++ b/main.cpp	Tue Feb 23 00:28:02 2016 +0000
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 //  cos波，sin波の同時発生，2次の IIR フィルタを使う方法
 //  アルゴリズム検証用プログラムのため，無駄な部分あり
-//  2016/02/16, Copyright (c) 2016 MIKAMI, Naoki
+//  2016/02/23, Copyright (c) 2016 MIKAMI, Naoki
 //------------------------------------------------------------------------------
 
 #include "ADC_BuiltIn.hpp"      // かならず必要
@@ -25,21 +25,20 @@
 
     float un1 = 0;  // u[-1] = 0;
     float un2 = 0;  // u[-2] = 0;
-    float xn1 = 1;  // x[-1]
-
+    float xn  = 1;  // x[n], 単位インパルス
     while (true)
     {
-        float xn = adc_.Read();         // A0 からの入力信号を読み込む（ダミー）
+        adc_.Read();    // 標本化クロックと同期をとるために必要
         //-----------------------------------------------
-        xn = 0;
-        float un = a1*un1 - un2  + xn1;
+        float un = a1*un1 - un2  + xn;
         
         float ynS = un1*b1S;        // sin
         float ynC = un - un1*b1C;   // cos
         
-        xn1 = xn;
         un2 = un1;
         un1 = un;
+
+        xn = 0;         // 単位インパルスなので次からは 0
         //-----------------------------------------------
         myDac_.Write(0.8f*ynS, 0.8f*ynC);   // DAC へ出力する
     }