Realtime spectrogram for DISCO-F746NG. On-board MEMS microphone is used for input sound signal. リアルタイムスペクトログラム.入力:MEMSマイク

Dependencies:   F746_GUI F746_SAI_IO UIT_FFT_Real

Revision:
0:9470a174c910
Child:
2:1f092ac020e1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MyClasses_Functions/FFT_Analysis.cpp	Sun May 22 06:28:40 2016 +0000
@@ -0,0 +1,28 @@
+//-------------------------------------------------------
+//  Class for spectrum analysis using FFT
+//
+//  2015/12/15, Copyright (c) 2015 MIKAMI, Naoki
+//-------------------------------------------------------
+
+#include "FFT_Analysis.hpp"
+
+namespace Mikami
+{
+    FftAnalyzer::FftAnalyzer(int nData, int nFft)
+        : AnalyzerBase(nData, nFft, nFft),
+          yFft_(new Complex[nFft/2+1]) {}
+
+    FftAnalyzer::~FftAnalyzer()
+    {
+        delete[] yFft_;
+    }
+
+    void FftAnalyzer::Analyze(const float xn[], float yn[])
+    {
+        fft_.Execute(xn, yFft_);    // Execute FFT
+        
+        // Translate to dB
+        for (int n=0; n<=N_FFT_/2; n++)
+            yn[n] = 10.0f*log10f(Norm(yFft_[n]));
+    }
+}