Kenji Arai / Mbed 2 deprecated CW_Decoder_using_FFT_on_DiscoF746NG

CW Decoder (Morse code decoder) 1st release version. mbed = 131 revision (Not latest) is used. Only run on DISCO-F746NG mbed board.

Dependencies:   BSP_DISCO_F746NG F746_GUI F746_SAI_IO LCD_DISCO_F746NG TS_DISCO_F746NG UIT_FFT_Real mbed

Base on F746_Spectrogram program created by 不韋 呂-san.
/users/MikamiUitOpen/code/F746_Spectrogram/
Thanks 不韋 呂-san to use fundamental parts such as FFT, SAI, GUI and other useful subroutines.
You do NOT need any modification for mbed hardware and NO additional circuits.
The mbed board read CW tone from your receiver speaker via MEMES microphone (on board) and show it on the screen.

MySpectrogram/Hamming.hpp

Committer:
kenjiArai
Date:
2017-02-05
Revision:
0:e608fc311e4e

File content as of revision 0:e608fc311e4e:

//-------------------------------------------------------------------
//  Hamming windowing with zero-padding
//
//  2016/07/23, Copyright (c) 2016 MIKAMI, Naoki
//-------------------------------------------------------------------

#ifndef HAMMING_WINDOW_HPP
#define HAMMING_WINDOW_HPP

#include "mbed.h"
#include "Array.hpp"

namespace Mikami
{
    class HammingWindow
    {
    public:
        // Constructor
        HammingWindow(uint16_t nData, uint16_t nFft)
                : N_(nData), NFFT_(nFft), w_(nData)
        {
            float pi2L = 6.283185f/(float)nData;
            for (int k=0; k<nData; k++)
                w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
        }
        
        // Destructor
        virtual ~HammingWindow() {}
        
        // Windowing
        void Execute(const float x[], float y[])
        {
            for (int n=0; n<N_; n++) y[n] = x[n]*w_[n];
            for (int n=N_; n<NFFT_; n++) y[n] = 0;
        }

    private:
        const int N_;
        const int NFFT_;
                
        Array<float> w_;

        // disallow copy constructor and assignment operator
        HammingWindow(const HammingWindow& );
        HammingWindow& operator=(const HammingWindow& );
    };
}
#endif  // HAMMING_WINDOW_HPP