File content as of revision 0:e608fc311e4e:

/*
 * mbed program / cwdecoder using the FFT Algorithm
 *   tested on DISCO-F746G mbed board
 *
 *  Modified by Kenji Arai
 *      http://www.page.sannet.ne.jp/kenjia/index.html
 *      http://mbed.org/users/kenjiArai/
 *
 *      Started:  January  28th, 2017
 *      Revised:  Feburary  5th, 2017
 *
 *  Reference program:
 *  1)  2016/10/02, Copyright (c) 2016 MIKAMI, Naoki
 *      https://developer.mbed.org/users/MikamiUitOpen/code/F746_Spectrogram/
 *  2)  http://skovholm.com/cwdecoder
 *      by Hjalmar Skovholm Hansen OZ1JHM
 */
 
//  Include --------------------------------------------------------------------
#include "mbed.h"
#include "SAI_InOut.hpp"
#include "F746_GUI.hpp"
#include "Matrix.hpp"
#include "NumericLabel.hpp"
#include "FFT_Analysis.hpp"
#include "MethodCollection.hpp"

#warning "If you would like to run this program, you need modify mbed revision."
#warning "Please set mbed revision 131 (dated on Dec. 15, 2016)"

//  Definition -----------------------------------------------------------------
//#define METHOD_COLLECTION_HPP   // MethodCollection.hpp will NOT use

#define HIGH            1
#define LOW             0
#define MILLIS()        t.read_ms()

#define ONE_LINE        34
#define LINES           11
#define WORK_LINE       LINES
#define TOTAL_CHAR      (ONE_LINE * LINES)

#define USE_COM
//#define USE_DEBUG

#ifdef USE_COM
#define BAUD(x)         pc.baud(x)
#define GETC(x)         pc.getc(x)
#define PUTC(x)         pc.putc(x)
#define PRINTF(...)     pc.printf(__VA_ARGS__)
#define READABLE(x)     pc.readable(x)
#else
#define BAUD(x)         {;}
#define GETC(x)         {;}
#define PUTC(x)         {;}
#define PRINTF(...)     {;}
#define READABLE(x)     {;}
#endif

#ifdef USE_DEBUG
#define DEBUG(...)      pc.printf(__VA_ARGS__)
#else
#define DEBUG(...)      {;}
#endif

using namespace Mikami;

//  ROM / Constant data --------------------------------------------------------
const int FS     = I2S_AUDIOFREQ_32K;
const int N_FFT  = 512;
#define SLOT_750HZ 12       // 32KHz /512 * 12 = 750Hz

char *const open_msg[] = {
    "Center freq.:       750 Hz",
    "Sampling freq.       32 kHz",   
    "FFT / # of points:  512",
    "Two modes ",
    "(1) CW / MORSE Decoder",
    "(2) Show Spectram"
};

//  RAM ------------------------------------------------------------------------
float       magnitude ;
int16_t     magnitudelimit      = 100;
int16_t     magnitudelimit_low  = 100;
int16_t     realstate = LOW;
int16_t     realstatebefore     = LOW;
int16_t     filteredstate       = LOW;
int16_t     filteredstatebefore = LOW;
int16_t     nbtime              = 2;         // ms noise blanker         
int32_t     starttimehigh;
int32_t     highduration;
int32_t     lasthighduration;
int32_t     hightimesavg;
int32_t     lowtimesavg;
int32_t     startttimelow;
int32_t     lowduration;
int32_t     laststarttime       = 0;
char        code[32];
int16_t     stop                = LOW;
int16_t     wpm;
uint32_t    cycle               = 0;
uint8_t     msg_lcd[LINES + 1][48];
uint8_t     num_last_line       = 0;
Array<float> sn(N_FFT+1);
Array<float> db(N_FFT/2+1);
LCD_DISCO_F746NG *lcd = GuiBase::GetLcdPtr();

//  Object ---------------------------------------------------------------------
Timer       t;
DigitalOut  myled(LED1);
DigitalOut  data_in(D5);
DigitalOut  loop_trg(D6);
DigitalOut  out_code(D7);
Serial      pc(USBTX, USBRX);
SaiIO       mySai(SaiIO::INPUT, N_FFT+1, FS, INPUT_DEVICE_DIGITAL_MICROPHONE_2);
FftAnalyzer fftAnalyzer(N_FFT+1, N_FFT);

//  Function prototypes --------------------------------------------------------
void    setup(void);
void    loop(void);
void    docode(void);
void    printascii(char);
void    adc_convert(void);
float   SpectrumUpdate(FftAnalyzer &analyzer,
        const Array<float> &sn, const Array<float> &db);
void    cw_decoder(void);
void    spectrogram(void);
uint8_t mode_slect(void);
void    spectrum(void);
//------------------------------------------------------------------------------
//  Control Program
//------------------------------------------------------------------------------
int main()
{
    while (true){
        lcd->Clear(GuiBase::ENUM_BACK);
        uint8_t n = mode_slect();
        switch (n){
            case 0:
                cw_decoder();
                break;
            case 1:
                spectrum();
                break;
            default:
                break;
        }
    }
}

uint8_t mode_slect()
{
    Label obj0(240, 2, "Operationg Mode",
               Label::CENTER, Font24, LCD_COLOR_LIGHTGREEN);
    Label obj1(40,  30, open_msg[0], Label::LEFT, Font20);
    Label obj2(40,  50, open_msg[1], Label::LEFT, Font20);
    Label obj3(40,  70, open_msg[2], Label::LEFT, Font20);
    Label obj4(40, 100, open_msg[3], Label::LEFT, Font20, LCD_COLOR_LIGHTGREEN);
    Label obj5(70, 120, open_msg[4], Label::LEFT, Font20, LCD_COLOR_LIGHTGREEN);
    Label obj6(70, 140, open_msg[5], Label::LEFT, Font20, LCD_COLOR_LIGHTGREEN);
    Button button0( 50, 200, 180, 50, "CW/MORSE", Font24);
    Button button1(260, 200, 180, 50, "SPECTRAM", Font24);
    while (true){
        if (button0.Touched()){     return 0UL;}
        if (button1.Touched()){     return 1UL;}
        wait(0.02f);
    }
}

void spectrogram()
{
    lcd->Clear(GuiBase::ENUM_BACK);
    PRINTF("\r\nFFT Spectroram\r\n");
    Button button10(380, 240, 80, 30, "MENUE", Font16);
        spectrum();
        if (button10.Touched()){     return;}
}

void cw_decoder()
{
    lcd->Clear(GuiBase::ENUM_BACK);
    PRINTF("\r\nCW Decoder(FFT) by JH1PJL\r\n");
    Label myLabel1(120, 250, "CW Decoder(FFT) by JH1PJL",
                    Label::CENTER, Font16);
    Button button20(380, 240, 80, 30, "MENUE", Font16);
    printf("Sys=%u\r\n", SystemCoreClock);
    lcd->SetTextColor(LCD_COLOR_GREEN);
    lcd->SetFont(&Font20);
    mySai.RecordIn();
    t.start();
    while (true){
        loop_trg = !loop_trg;
        data_in = 1;
        while (mySai.IsCaptured() == false){;}
        for (int n=0; n<mySai.GetLength(); n++){
            int16_t xL, xR;
            mySai.Input(xL, xR);
            sn[n] = (float)xL;
        }
        data_in = 0;
        //magnitude = SpectrumUpdate(spectra, fftAnalyzer, sn, db);
        magnitude = SpectrumUpdate(fftAnalyzer, sn, db);
        //printf("%f\r\n", magnitude);
        if (magnitude > magnitudelimit_low){ // magnitude limit automatic
            magnitudelimit =    // moving average filter
                    (magnitudelimit +((magnitude - magnitudelimit) / 6.0f));
        }
        if (magnitudelimit < magnitudelimit_low){
            magnitudelimit = magnitudelimit_low;
        }
        // check for the magnitude
        if(magnitude > magnitudelimit * 0.9f){ // just to have some space up 
            realstate = HIGH; 
        } else {
            realstate = LOW;
        }
        // clean up the state with a noise blanker
        if (realstate != realstatebefore){
            laststarttime = MILLIS();
        }
        if ((MILLIS()-laststarttime)> nbtime){
            if (realstate != filteredstate){
                filteredstate = realstate;
            }
        }
        // durations on high and low
        if (filteredstate != filteredstatebefore){
            if (filteredstate == HIGH){
                starttimehigh = MILLIS();
                lowduration = (MILLIS() - startttimelow);
            }
            if (filteredstate == LOW){
                startttimelow = MILLIS();
                highduration = (MILLIS() - starttimehigh);
                if (highduration < (2.0f *hightimesavg) || hightimesavg == 0.0f){
                    // now we know avg dit time ( rolling 3 avg)
                    hightimesavg = (highduration+hightimesavg+hightimesavg) / 3.0f;
                }
                if (highduration > (5.0f * hightimesavg) ){
                    // if speed decrease fast ..
                    hightimesavg = highduration+hightimesavg;
                }
            }
        }
        // now we will check which kind of baud we have - dit or dah
        // and what kind of pause we do have 1 - 3 or 7 pause
        // we think that hightimeavg = 1 bit
        if (filteredstate != filteredstatebefore){
            stop = LOW;
            if (filteredstate == LOW){  //// we did end a HIGH
                // 0.6 filter out false dits
                if (highduration < (hightimesavg * 2.0f)
                     && highduration > (hightimesavg * 0.6f)){ 
                    strcat(code,".");
                    DEBUG(".");
                }
                if (highduration > (hightimesavg*2)
                     && highduration < (hightimesavg * 6.0f)){ 
                    strcat(code,"-");
                    DEBUG("-");
                    wpm = (wpm + (1200/((highduration)/3)))/2;
                }
            }
            if (filteredstate == HIGH){  // we did end a LOW
                float lacktime = 1;
                //  when high speeds we have to have a little more pause
                //  before new letter or new word
                if(wpm > 25){   lacktime = 1.0f;} 
                if(wpm > 30){   lacktime = 1.2f;}
                if(wpm > 35){   lacktime = 1.5f;}
                if(wpm > 40){   lacktime = 1.7f;}
                if(wpm > 45){   lacktime = 1.9f;}
                if(wpm > 50){   lacktime = 2.0f;}
                if (lowduration > (hightimesavg*(2.0f * lacktime))
                            && lowduration < hightimesavg*(5.0f * lacktime)){
                    docode();
                    code[0] = '\0';
                    DEBUG("/");
                }
                if (lowduration >= hightimesavg*(5.0f * lacktime)){ // word space
                    docode();
                    code[0] = '\0';
                    printascii(' ');
                    DEBUG("\r\n");
                }
            }
        }
        // write if no more letters
        if ((MILLIS() - startttimelow) > (highduration * 6.0f) && stop == LOW){
            docode();
            code[0] = '\0';
            stop = HIGH;
        }
        // we will turn on and off the LED
        // and the speaker
        if(filteredstate == HIGH){ 
            myled = HIGH;
        } else {
            myled = LOW;
        }
        // the end of main loop clean up
        realstatebefore = realstate;
        lasthighduration = highduration;
        filteredstatebefore = filteredstate;
        DEBUG("%d\r\n", t.read_ms());
        // return to menue or continue
        if (button20.Touched()){     return;}
    }
}

float SpectrumUpdate(FftAnalyzer &analyzer,
                    const Array<float> &sn, const Array<float> &db)
{
    analyzer.Execute(sn, db);
    return (db[SLOT_750HZ] - 20) * 2;
}

// translate cw code to ascii
void docode()
{
    //PRINTF("decording<%s>", code);
    if (code[0] == '.'){             // .
        if (code[1] == '.'){         // ..
            if (code[2] == '.'){     // ...
                if (code[3] == '.'){ // ....
                    if (strcmp(code,"...."   ) == 0){ printascii('H'); return;}
                    if (strcmp(code,"....."  ) == 0){ printascii('5'); return;}
                    if (strcmp(code,"....-"  ) == 0){ printascii('4'); return;}
                } else if (code[3] == '-'){     // ...-
                    if (code[4] == '.'){        // ...-.
                        if (strcmp(code,"...-."  ) == 0)
                                                    { printascii(126); return;}
                        if (strcmp(code,"...-.-" ) == 0)
                                                    { printascii(62);  return;}
                        if (strcmp(code,"...-..-") == 0)
                                                    { printascii(36);  return;}
                    } else if (code[4] == '-'){ // ...--
                        if (strcmp(code,"...--"  ) == 0)
                                                    { printascii('3'); return;}
                    } else {
                        if (strcmp(code,"...-"   ) == 0)
                                                    { printascii('V'); return;} 
                    }
                } else {                        // ...
                    if (strcmp(code,"..."    ) == 0){ printascii('S'); return;}
                }
            } else if (code[2] == '-'){ // ..-
                if (strcmp(code,"..-"    ) == 0){ printascii('U');  return;}
                if (strcmp(code,"..-."   ) == 0){ printascii('F');  return;}
                if (strcmp(code,"..---"  ) == 0){ printascii('2');  return;}
                if (strcmp(code,"..--.." ) == 0){ printascii(63);   return;}
            } else {                    // ..
                if (strcmp(code,".."      ) == 0){ printascii('I');  return;}
            }
        } else if (code[1] == '-'){         // .-
            if (code[2] == '.'){            // .-.
                if (code[3] == '.'){        // .-..
                    if (strcmp(code,".-.."   ) == 0){ printascii('L'); return;}
                    if (strcmp(code,".-..."  ) == 0){ printascii(95);  return;}
                } else if (code[3] == '-'){ // .-.-
                    if (strcmp(code,".-.-"   ) == 0){ printascii(3);   return;}
                    if (strcmp(code,".-.-."  ) == 0){ printascii(60);  return;}
                    if (strcmp(code,".-.-.-" ) == 0){ printascii(46);  return;}
                } else {                    // .-.
                    if (strcmp(code,".-."    ) == 0){ printascii('R'); return;}
                }
            } else if (code[2] == '-'){     // .--
                if (code[3] == '.'){        // .--.
                    if (strcmp(code,".--."   ) == 0){ printascii('P'); return;}
                    if (strcmp(code,".--.-"  ) == 0){ printascii('-'); return;}
                    if (strcmp(code,".--.-." ) == 0){ printascii(64);  return;}
                } else if (code[3] == '-'){ // .---
                    if (strcmp(code,".---"   ) == 0){ printascii('J'); return;}
                    if (strcmp(code,".----"  ) == 0){ printascii('1'); return;}
                } else {                    // .--
                    if (strcmp(code,".--"    ) == 0){ printascii('W'); return;}
                }
            } else {                        // .-
                if (strcmp(code,".-") == 0){ printascii('A'); return;}
            }
        } else {    // .
            if (strcmp(code,".") == 0){ printascii('E'); return;}
        }
    } else if (code[0] == '-'){             // -
        if (code[1] == '.'){                // -.
            if (code[2] == '.'){            // -..
                if (code[3] == '.'){        // -...
                    if (strcmp(code,"-..."   ) == 0){ printascii('B'); return;}
                    if (strcmp(code,"-...."  ) == 0){ printascii('6'); return;}
                    if (strcmp(code,"-....-" ) == 0){ printascii('-'); return;}
                } else if (code[3] == '-'){ // -..-
                    if (strcmp(code,"-..-"   ) == 0){ printascii('X'); return;}
                    if (strcmp(code,"-..-."  ) == 0){ printascii(47);  return;}
                } else {
                    if (strcmp(code,"-.."    ) == 0){ printascii('D'); return;}
                }
            } else if (code[2] == '-'){     // -.-
                if (code[3] == '.'){        // -.-.
                    if (strcmp(code,"-.-."   ) == 0){ printascii('C'); return;}
                    if (strcmp(code,"-.-.--" ) == 0){ printascii(33);  return;}
                } else if (code[3] == '-'){ // -.--
                    if (strcmp(code,"-.--"   ) == 0){ printascii('Y'); return;}
                    if (strcmp(code,"-.--."  ) == 0){ printascii(40);  return;}
                    if (strcmp(code,"-.--.-" ) == 0){ printascii(41);  return;}
                } else {                    // -.-
                    if (strcmp(code,"-.-"    ) == 0){ printascii('K'); return;}
                }
            } else {                        // -.
                if (strcmp(code,"-.") == 0){ printascii('N'); return;}
            }
        } else if (code[1] == '-'){         // -
            if (code[2] == '.'){            // --.
                if (strcmp(code,"--."    ) == 0){ printascii('G'); return;}
                if (strcmp(code,"--.."   ) == 0){ printascii('Z'); return;}
                if (strcmp(code,"--.-"   ) == 0){ printascii('Q'); return;}
                if (strcmp(code,"--..."  ) == 0){ printascii('7'); return;}
                if (strcmp(code,"--..--" ) == 0){ printascii(44);  return;}                                         
            } else if (code[2] == '-'){     // ---
                if (code[3] == '.'){        // ---.
                    if (strcmp(code,"---.."  ) == 0){ printascii('8'); return;}
                    if (strcmp(code,"---."   ) == 0){ printascii(4);   return;}
                    if (strcmp(code,"---..." ) == 0){ printascii(58);  return;}
                } else if (code[3] == '-'){ // ----
                    if (strcmp(code,"----."  ) == 0){ printascii('9'); return;}
                    if (strcmp(code,"-----"  ) == 0){ printascii('0'); return;}
                } else {                    // ---
                    if (strcmp(code,"---"    ) == 0){ printascii('O'); return;}
                } 
            } else {        // --
                if (strcmp(code,"--") == 0){ printascii('M'); return;}
            }
        } else {    // -
            if (strcmp(code,"-") == 0){ printascii('T'); return;}
        }
    }   
}

void printascii(char c)
{
    uint8_t i,j;

    out_code = 1;
    PRINTF("%c", c);
    msg_lcd[WORK_LINE][num_last_line++] = c;
    if (num_last_line == ONE_LINE){
        for (j = 0; j < LINES; j++){ // scroll one line
            for (i =0; i < ONE_LINE; i++){
                msg_lcd[j][i] = msg_lcd[j+1][i];
            }
        }
        for (i =0; i < ONE_LINE; i++){  // Clear last line
            msg_lcd[WORK_LINE][i] = ' ';
        }
        num_last_line = 0;
        for (i =0; i < (WORK_LINE + 1); i++){
            lcd->DisplayStringAtLine( i, &msg_lcd[i][0]);
        }
    } else {
        lcd->DisplayStringAtLine(WORK_LINE, &msg_lcd[WORK_LINE][0]);
    }
    out_code = 0;
}

//------------------------------------------------
//  リアルタイム・スペクトログラム
//      入力： MEMS マイク
//
//  2016/10/02, Copyright (c) 2016 MIKAMI, Naoki
//  modified by JH1PJL
//------------------------------------------------
void spectrum()
{
    const int FS = I2S_AUDIOFREQ_16K;   // 標本化周波数：　16 kHz
    const int N_FFT = 512;              // FFT の点数
    const float FRAME = (N_FFT/(float)FS)*1000.0f;  // 1 フレームに対応する時間（単位：ms）

    const int X0    = 40;           // 表示領域の x 座標の原点
    const int Y0    = 200;          // 表示領域の y 座標の原点
    const int H0    = 160;          // 表示する際の周波数軸の長さ（5 kHz に対応）
    const uint16_t PX_1KHZ = H0/5;  // 1 kHz に対応するピクセル数
    const int W0    = 360;          // 横方向の全体の表示の幅（単位：ピクセル）
    const int H_BAR = 2;            // 表示する際の 1 フレームに対応する横方向のピクセル数
    const int SIZE_X = W0/H_BAR;
    const uint16_t MS100 = 100*H_BAR/FRAME; // 100 ms に対応するピクセル数
    const uint32_t AXIS_COLOR = LCD_COLOR_WHITE;//0xFFCCFFFF;
    
    Matrix<uint32_t> spectra(SIZE_X, H0+1, GuiBase::ENUM_BACK);

    SaiIO mySai(SaiIO::INPUT, N_FFT+1, FS,
                INPUT_DEVICE_DIGITAL_MICROPHONE_2);

    LCD_DISCO_F746NG *lcd = GuiBase::GetLcdPtr();   // LCD 表示器のオブジェクト
    lcd->Clear(GuiBase::ENUM_BACK);
    Label myLabel1(240, 2, "Real-time spectrogram", Label::CENTER, Font16);

    // ButtonGroup の設定
    const uint16_t B_W = 50;
    const uint16_t B_Y = 242;
    const uint16_t B_H = 30;
    const string RUN_STOP[3] = {"MENUE","RUN", "STOP"};
    ButtonGroup runStop(285, B_Y, B_W, B_H, 3, RUN_STOP, 0, 0, 3, 1);
    
    Button clear(430, B_Y, B_W, B_H, "CLEAR");
    clear.Inactivate();
    // ButtonGroup の設定（ここまで）

    // 座標軸
    DrawAxis(X0, Y0, W0, H0, AXIS_COLOR, MS100, PX_1KHZ, lcd);

    Array<float> sn(N_FFT+1);
    Array<float> db(N_FFT/2+1);

    // 色と dB の関係の表示
    ColorDb(Y0, AXIS_COLOR, lcd);
        
    FftAnalyzer fftAnalyzer(N_FFT+1, N_FFT);

    // ループ内で使う変数の初期化
    int stop = 1;       // 0: run, 1: stop

    while(!runStop.GetTouchedNumber(stop)) {}
    // データ読み込み開始
    mySai.RecordIn();
  
    while (true)
    {
        runStop.GetTouchedNumber(stop);

        if (stop == 0){
            NVIC_SystemReset();
        }
        else if (stop == 1)
        {
            clear.Inactivate();
            if (mySai.IsCaptured())
            {
                // １フレーム分の信号の入力
                for (int n=0; n<mySai.GetLength(); n++)
                {
                    int16_t xL, xR;
                    mySai.Input(xL, xR);
                    sn[n] = (float)xL;
                }
                //mySai.ResetCaptured();

                // スペクトルの更新
                SpectrumUpdate(spectra, fftAnalyzer, sn, db);
                // スペクトルの表示
                DisplaySpectrum(spectra, X0, Y0, H_BAR, lcd);
            }
        }
        else if (stop == 2)
        {
            if (!clear.IsActive()) clear.Activate();
            if (clear.Touched())
            {
                spectra.Fill(GuiBase::ENUM_BACK);   // スペクトルの表示をクリア
                DisplaySpectrum(spectra, X0, Y0, H_BAR, lcd);
                clear.Draw();
            }
        }
    }
}