DCF77_v0_4.ino

/***********************************************************************
   Copyright (c) 2016, Frank Bösing, f.boesing@gmx.de & Frank DD4WH, dd4wh.swl@gmail.com

    Teensy DCF77 Receiver & Real Time Clock

    uses only minimal hardware to receive accurate time signals

    For information on how to setup the antenna, see here:

    https://github.com/DD4WH/Teensy-DCF77/wiki
*/
#define VERSION     " v0.42"
/*
   Permission is hereby granted, free of charge, to any person obtaining a copy
   of this software and associated documentation files (the "Software"), to deal
   in the Software without restriction, including without limitation the rights
   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   copies of the Software, and to permit persons to whom the Software is
   furnished to do so, subject to the following conditions:

   The above copyright notice, development funding notice, and this permission
   notice shall be included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   THE SOFTWARE.

*/

#include <Time.h>
#include <TimeLib.h>

#include <Audio.h>
#include <SPI.h>
#include <Metro.h>
#include <ILI9341_t3.h>
#include "font_Arial.h"

time_t getTeensy3Time()
{
  return Teensy3Clock.get();
}

//#include <FlexiBoard.h>

  #define BACKLIGHT_PIN
  #define TFT_DC      20
  #define TFT_CS      21
  #define TFT_RST     32  // 255 = unused. connect to 3.3V
  #define TFT_MOSI     7
  #define TFT_SCLK    14
  #define TFT_MISO    12

ILI9341_t3 tft = ILI9341_t3(TFT_CS, TFT_DC, TFT_RST, TFT_MOSI, TFT_SCLK, TFT_MISO);

#define SAMPLE_RATE_MIN               0
#define SAMPLE_RATE_8K                0
#define SAMPLE_RATE_11K               1
#define SAMPLE_RATE_16K               2
#define SAMPLE_RATE_22K               3
#define SAMPLE_RATE_32K               4
#define SAMPLE_RATE_44K               5
#define SAMPLE_RATE_48K               6
#define SAMPLE_RATE_88K               7
#define SAMPLE_RATE_96K               8
#define SAMPLE_RATE_176K              9
#define SAMPLE_RATE_192K              10
#define SAMPLE_RATE_MAX               10


AudioInputI2S            i2s_in;         //xy=202,411
AudioSynthWaveformSine   sine1;          //xy=354,249
AudioFilterBiquad        biquad1;        //xy=394,403
AudioEffectMultiply      mult1;          //xy=594,250
AudioFilterBiquad        biquad2;        //xy=761,248
//AudioAnalyzeFFT256       myFFT;          //xy=962,434
AudioAnalyzeFFT1024       myFFT;          //xy=962,434
AudioOutputI2S           i2s_out;        //xy=975,247
AudioConnection          patchCord1(i2s_in, 0, biquad1, 0);
AudioConnection          patchCord2(sine1, 0, mult1, 1);
AudioConnection          patchCord3(biquad1, 0, mult1, 0);
AudioConnection          patchCord4(biquad1, myFFT);
AudioConnection          patchCord5(mult1, biquad2);
AudioConnection          patchCord6(biquad2, 0, i2s_out, 1);
AudioConnection          patchCord7(biquad2, 0, i2s_out, 0);
AudioControlSGTL5000     sgtl5000_1;

// Metro 1 second
Metro second_timer = Metro(1000);

const uint16_t FFT_points = 1024;
//const uint16_t FFT_points = 256;

int8_t mic_gain = 38 ;//start detecting with this MIC_GAIN in dB
const float bandpass_q = 10; // be careful when increasing Q, distortion can occur with higher Q because of fixed point 16bit math in the biquads
const float DCF77_FREQ = 77500.0; //DCF-77 77.65 kHz
// start detecting at this frequency, so that
// you can hear a 600Hz tone [77.5 - 76.9 = 0.6kHz]
unsigned int freq_real = DCF77_FREQ - 600;

//const unsigned int sample_rate = SAMPLE_RATE_176K;
//unsigned int sample_rate_real = 176400;
const unsigned int sample_rate = SAMPLE_RATE_192K;
unsigned int sample_rate_real = 192000;


unsigned int freq_LO = 7000;
float dcf_signal = 0;
float dcf_threshold = 0;
float dcf_med = 0;
unsigned int DCF_bin;// this is the FFT bin where the 77.5kHz signal is

bool timeflag = 0;
const int8_t pos_x_date = 14;
const int8_t pos_y_date = 68;
const int8_t pos_x_time = 14;
const int8_t pos_y_time = 114;
uint8_t hour10_old;
uint8_t hour1_old;
uint8_t minute10_old;
uint8_t minute1_old;
uint8_t second10_old;
uint8_t second1_old;
uint8_t precision_flag = 0;
int8_t mesz = -1;
int8_t mesz_old = 0;

const float displayscale = 2.5;

typedef struct SR_Descriptor
{
  const int SR_n;
  const char* const f1;
  const char* const f2;
  const char* const f3;
  const char* const f4;
  const float32_t x_factor;
} SR_Desc;

// Text and position for the FFT spectrum display scale
const SR_Descriptor SR[SAMPLE_RATE_MAX + 1] =
{
  //   SR_n ,  f1, f2, f3, f4, x_factor = pixels per f1 kHz in spectrum display
  {  SAMPLE_RATE_8K,  " 1", " 2", " 3", " 4", 64.0}, // which means 64 pixels per 1 kHz
  {  SAMPLE_RATE_11K,  " 1", " 2", " 3", " 4", 43.1},
  {  SAMPLE_RATE_16K,  " 2", " 4", " 6", " 8", 64.0},
  {  SAMPLE_RATE_22K,  " 2", " 4", " 6", " 8", 43.1},
  {  SAMPLE_RATE_32K,  "5", "10", "15", "20", 80.0},
  {  SAMPLE_RATE_44K,  "5", "10", "15", "20", 58.05},
  {  SAMPLE_RATE_48K,  "5", "10", "15", "20", 53.33},
  {  SAMPLE_RATE_88K,  "10", "20", "30", "40", 58.05},
  {  SAMPLE_RATE_96K,  "10", "20", "30", "40", 53.33},
  {  SAMPLE_RATE_176K,  "20", "40", "60", "80", 58.05},
  {  SAMPLE_RATE_192K,  "20", "40", "60", "80", 53.33} // which means 53.33 pixels per 20kHz
};

//const int myInput = AUDIO_INPUT_LINEIN;
const int myInput = AUDIO_INPUT_MIC;

//const char* const Days[7] = { "Samstag", "Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag"};
const char* const Days[7] = { "Saturday", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday"};

void setup();
void loop();

//=========================================================================

void setup() {

  Serial.begin(115200);

  setSyncProvider(getTeensy3Time);

  // Audio connections require memory.
  AudioMemory(16);

  // Enable the audio shield. select input. and enable output
  sgtl5000_1.enable();
  sgtl5000_1.inputSelect(myInput);
  sgtl5000_1.volume(0.9);
  sgtl5000_1.micGain (mic_gain);
  sgtl5000_1.adcHighPassFilterDisable(); // does not help too much!

  // Init TFT display
  pinMode( BACKLIGHT_PIN, OUTPUT );
  analogWrite( BACKLIGHT_PIN, 1023 );
  tft.begin();
  tft.setRotation( 3 );
  tft.fillScreen(ILI9341_BLACK);
  tft.setCursor(14, 7);
  tft.setTextColor(ILI9341_ORANGE);
  tft.setFont(Arial_12);
  tft.print("Teensy DCF77 Receiver "); tft.print(VERSION);
  tft.setTextColor(ILI9341_WHITE);
  //  display_settings();

  set_sample_rate (sample_rate);
  set_freq_LO (freq_real);
  //  decodeTelegram( 0x8b47c0501a821b80ULL );
  displayDate();
  displayClock();
  displayPrecisionMessage();
} // END SETUP


void loop() {

  if (myFFT.available())
  {
    agc();
    detectBit();
    spectrum();
    displayClock();
  }
  //  check_processor();
}

void set_mic_gain(int8_t gain) {
  // AudioNoInterrupts();
  sgtl5000_1.micGain (mic_gain);
  // AudioInterrupts();
  //  display_settings();
} // end function set_mic_gain

void       set_freq_LO(int freq) {
  // audio lib thinks we are still in 44118sps sample rate
  // therefore we have to scale the frequency of the local oscillator
  // in accordance with the REAL sample rate
  freq_LO = freq * (AUDIO_SAMPLE_RATE_EXACT / sample_rate_real);
  // if we switch to LOWER samples rates, make sure the running LO
  // frequency is allowed ( < 22k) ! If not, adjust consequently, so that
  // LO freq never goes up 22k, also adjust the variable freq_real
  if (freq_LO > 22000) {
    freq_LO = 22000;
    freq_real = freq_LO * (sample_rate_real / AUDIO_SAMPLE_RATE_EXACT) + 9;
  }
  AudioNoInterrupts();
  sine1.frequency(freq_LO);
  AudioInterrupts();
  //  display_settings();
} // END of function set_freq_LO

void      display_settings() {
  tft.fillRect(14, 32, 200, 17, ILI9341_BLACK);
  tft.setCursor(14, 32);
  tft.setFont(Arial_12);
  tft.print("gain: "); tft.print (mic_gain);
  tft.print("     ");
  tft.print("freq: "); tft.print (freq_real);
  tft.print("    ");
  tft.fillRect(232, 32, 88, 17, ILI9341_BLACK);
  tft.setCursor(232, 32);
  tft.print("       ");
  tft.print(sample_rate_real / 1000); tft.print("k");
}

void      set_sample_rate (int sr) {
  switch (sr) {
    case SAMPLE_RATE_8K:
      sample_rate_real = 8000;
      break;
    case SAMPLE_RATE_11K:
      sample_rate_real = 11025;
      break;
    case SAMPLE_RATE_16K:
      sample_rate_real = 16000;
      break;
    case SAMPLE_RATE_22K:
      sample_rate_real = 22050;
      break;
    case SAMPLE_RATE_32K:
      sample_rate_real = 32000;
      break;
    case SAMPLE_RATE_44K:
      sample_rate_real = 44100;
      break;
    case SAMPLE_RATE_48K:
      sample_rate_real = 48000;
      break;
    case SAMPLE_RATE_88K:
      sample_rate_real = 88200;
      break;
    case SAMPLE_RATE_96K:
      sample_rate_real = 96000;
      break;
    case SAMPLE_RATE_176K:
      sample_rate_real = 176400;
      break;
    case SAMPLE_RATE_192K:
      sample_rate_real = 192000;
      break;
  }
  AudioNoInterrupts();
  sample_rate_real = setI2SFreq(sample_rate_real);

  delay(200); // this delay seems to be very essential !
  set_freq_LO (freq_real);

  // never set the lowpass freq below 1700 (empirically derived by ear ;-))
  // distortion will occur because of precision issues due to fixed point 16bit in the biquads
  biquad2.setLowpass(0, 1700, 0.54);
  biquad2.setLowpass(1, 1700, 1.3);
  biquad2.setLowpass(2, 1700, 0.54);
  biquad2.setLowpass(3, 1700, 1.3);

  biquad1.setBandpass(0, DCF77_FREQ * (AUDIO_SAMPLE_RATE_EXACT / sample_rate_real), bandpass_q);
  biquad1.setBandpass(1, DCF77_FREQ * (AUDIO_SAMPLE_RATE_EXACT / sample_rate_real), bandpass_q);
  biquad1.setBandpass(2, DCF77_FREQ * (AUDIO_SAMPLE_RATE_EXACT / sample_rate_real), bandpass_q);
  biquad1.setBandpass(3, DCF77_FREQ * (AUDIO_SAMPLE_RATE_EXACT / sample_rate_real), bandpass_q);

  AudioInterrupts();
  delay(20);
  DCF_bin = round((DCF77_FREQ / (sample_rate_real / 2.0)) * (FFT_points / 2));
  Serial.print("DCF77_bin number: "); Serial.println(DCF_bin);

  //  display_settings();
  prepare_spectrum_display();

} // END function set_sample_rate

void prepare_spectrum_display() {
  int base_y = 211;
  int b_x = 10;
  int x_f = SR[sample_rate].x_factor;
  tft.fillRect(0, base_y, 320, 240 - base_y, ILI9341_BLACK);
  //    tft.drawFastHLine(b_x, base_y + 2, 256, ILI9341_PURPLE);
  //    tft.drawFastHLine(b_x, base_y + 3, 256, ILI9341_PURPLE);
  tft.drawFastHLine(b_x, base_y + 2, 256, ILI9341_MAROON);
  tft.drawFastHLine(b_x, base_y + 3, 256, ILI9341_MAROON);
  // vertical lines
  tft.drawFastVLine(b_x - 4, base_y + 1, 10, ILI9341_YELLOW);
  tft.drawFastVLine(b_x - 3, base_y + 1, 10, ILI9341_YELLOW);
  tft.drawFastVLine( x_f + b_x,  base_y + 1, 10, ILI9341_YELLOW);
  tft.drawFastVLine( x_f + 1 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
  tft.drawFastVLine( x_f * 2 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
  tft.drawFastVLine( x_f * 2 + 1 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
  if (x_f * 3 + b_x < 256 + b_x) {
    tft.drawFastVLine( x_f * 3 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
    tft.drawFastVLine( x_f * 3 + 1 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
  }
  if (x_f * 4 + b_x < 256 + b_x) {
    tft.drawFastVLine( x_f * 4 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
    tft.drawFastVLine( x_f * 4 + 1 + b_x,  base_y + 1, 10, ILI9341_YELLOW);
  }
  tft.drawFastVLine( x_f * 0.5 + b_x,  base_y + 1, 6, ILI9341_YELLOW);
  tft.drawFastVLine( x_f * 1.5 + b_x,  base_y + 1, 6, ILI9341_YELLOW);
  tft.drawFastVLine( x_f * 2.5 + b_x,  base_y + 1, 6, ILI9341_YELLOW);
  if (x_f * 3.5 + b_x < 256 + b_x) {
    tft.drawFastVLine( x_f * 3.5 + b_x,  base_y + 1, 6, ILI9341_YELLOW);
  }
  if (x_f * 4.5 + b_x < 256 + b_x) {
    tft.drawFastVLine( x_f * 4.5 + b_x,  base_y + 1, 6, ILI9341_YELLOW);
  }
  // text
  tft.setTextColor(ILI9341_WHITE);
  tft.setFont(Arial_9);
  int text_y_offset = 16;
  int text_x_offset = - 5;
  // zero
  tft.setCursor (b_x + text_x_offset, base_y + text_y_offset);
  tft.print(0);
  tft.setCursor (b_x + x_f + text_x_offset, base_y + text_y_offset);
  tft.print(SR[sample_rate].f1);
  tft.setCursor (b_x + x_f * 2 + text_x_offset, base_y + text_y_offset);
  tft.print(SR[sample_rate].f2);
  tft.setCursor (b_x + x_f * 3 + text_x_offset, base_y + text_y_offset);
  tft.print(SR[sample_rate].f3);
  tft.setCursor (b_x + x_f * 4 + text_x_offset, base_y + text_y_offset);
  tft.print(SR[sample_rate].f4);
  //    tft.setCursor (b_x + text_x_offset + 256, base_y + text_y_offset);
  tft.print(" kHz");

  tft.setFont(Arial_14);
} // END prepare_spectrum_display


void agc() {
  static unsigned long tspeed = millis(); //Timer for startup

  const float speed_agc_start = 0.995;   //initial speed AGC
  const float speed_agc_run   = 0.9995;
  static float speed_agc = speed_agc_start;
  static unsigned long tagc = millis(); //Timer for AGC

  const float speed_thr = 0.995;

  //  tft.drawFastHLine(14, 220 - dcf_med, 256, ILI9341_BLACK);
  tft.drawFastHLine(220, 220 - dcf_med, 46, ILI9341_BLACK);
  dcf_signal = (abs(myFFT.output[DCF_bin]) + abs(myFFT.output[DCF_bin + 1])) * displayscale;
  if (dcf_signal > 175) dcf_signal  = 175;
  else if (dcf_med == 0) dcf_med = dcf_signal;
  dcf_med = (1 - speed_agc) * dcf_signal + speed_agc * dcf_med;
  tft.drawFastHLine(220, 220 - dcf_med, 46, ILI9341_ORANGE);

  tft.drawFastHLine(220, 220 - dcf_threshold, 46, ILI9341_BLACK);
  dcf_threshold = (1 - speed_thr) * dcf_signal + speed_thr * dcf_threshold;
  tft.drawFastHLine(220, 220 - dcf_threshold, 46, ILI9341_GREEN);

  unsigned long t = millis();
  //Slow down speed after a while
  if ((t - tspeed > 1500) && (t - tspeed < 3500) ) {
    if (speed_agc < speed_agc_run) {
      speed_agc = speed_agc_run;
      Serial.printf("Set AGC-Speed %f\n", speed_agc);
    }
  }

  if ((t - tagc > 2221) || (speed_agc == speed_agc_start)) {
    tagc = t;
    if ((dcf_med > 160) && (mic_gain > 30)) {
      mic_gain--;
      set_mic_gain(mic_gain);
      Serial.printf("(Gain: %d)", mic_gain);
    }
    if ((dcf_med < 100) && (mic_gain < 58)) {
      mic_gain++;
      set_mic_gain(mic_gain);
      Serial.printf("(Gain: %d)", mic_gain);
    }
  }
}

int getParity(uint32_t value) {
  int par = 0;
  while (value) {
    value = value & (value - 1);
    par = ~par;
  }
  return par & 1;
}


int decodeTelegram(uint64_t telegram) {
  uint16_t minute, hour, day, weekday, month, year, v10;
  int parity;

  //Plausibility checks and decoding telegram
  //Example-Data: 0x8b47c14f468f9ec0ULL : 2016/11/20

  //https://de.wikipedia.org/wiki/DCF77

  //TODO : more plausibility-checks to prevent false positives

  //Check fixed - bits:
  if ( ((telegram & 1) != 0) || ((telegram >> 20) & 1) == 0) {
    Serial.println("Fixed-Bit error\n");
    return 0;
  }

  //MESZ Central European Summer Time ?
  mesz = (telegram >> 17) & 1;
  if ( mesz != (~(telegram >> 18) & 1) ) {
    Serial.println("MESZ-Bit error\n");
    return 0;
  }

  //1. decode date & date-parity-bit
  parity = telegram >> 58 & 0x01;
  if (getParity( (telegram >> 36) & 0x3fffff) != parity) return 0;
  year = ((telegram >> 54) & 0x0f) * 10 + ((telegram >> 50) & 0x0f);
  if (year < 16) return 0;

  month = ((telegram >> 45) & 0x0f);
  if (month > 9) return 0;

  month = ((telegram >> 49) & 0x01) * 10 + month;
  if ((month == 0) || (month > 12)) return 0;

  weekday = ((telegram >> 42) & 0x07);
  if (weekday == 0) return 0;

  day = ((telegram >> 36) & 0x0f);
  if (day > 9) return 0;
  day = ((telegram >> 40) & 0x03) * 10 + day;
  if ( (day == 0) || (day > 31) ) return 0;//Todo add check on 29.feb, 30/31 and more...


  //2. decode time & parity-bit
  parity = telegram >> 35 & 0x01;
  if  (getParity( (telegram >> 29) & 0x3f) != parity) return 0;
  hour = (telegram >> 29 & 0x0f);
  if (hour > 9) return 0;
  v10 = (telegram >> 33 & 0x03);
  if (v10 > 2) return 0;
  hour = v10 * 10 + hour;
  if (hour > 23) return 0;

  parity = telegram >> 28 & 0x01;
  if (getParity( (telegram >> 21) & 0x7f ) != parity) return 0;
  minute = (telegram >> 21 & 0x0f);
  if (minute > 9) return 0;
  v10 = (telegram >> 25 & 0x07);
  if (v10 > 5) return 0;
  minute = v10 * 10 + minute;
  if (minute > 59) return 0;


  //All data seem to be ok.
  Serial.printf("Time set: %d.%d.20%d %d:%02d %s\n", day, month, year, hour, minute, mesz ? "MESZ" : "MEZ");
  setTime (hour, minute, 0, day, month, year);
  Teensy3Clock.set(now());
  displayDate();
  return 1;
}

void displayPrecisionMessage() {
  if (precision_flag) {
    tft.fillRect(14, 32, 300, 18, ILI9341_BLACK);
    tft.setCursor(14, 32);
    tft.setFont(Arial_11);
    tft.setTextColor(ILI9341_GREEN);
    tft.print("Full precision of time and date");
    tft.drawRect(290, 4, 20, 20, ILI9341_GREEN);
  }
  else
  {
    tft.fillRect(14, 32, 300, 18, ILI9341_BLACK);
    tft.setCursor(14, 32);
    tft.setFont(Arial_11);
    tft.setTextColor(ILI9341_RED);
    tft.print("Unprecise, trying to collect data");
    tft.drawRect(290, 4, 20, 20, ILI9341_RED);
  }
} // end function displayPrecisionMessage

int decode(unsigned long t) {
  static uint64_t data = 0;
  static int sec = 0;
  static unsigned long tlastBit = 0;
  int bit;
  unsigned long m;

  m = millis();
  if ( m - tlastBit > 1600) {
    Serial.printf(" End Of Telegram. Data: 0x%llx %d Bits\n", data, sec);
    tft.fillRect(14, 54, 59 * 5, 3, ILI9341_BLACK);
    if (sec == 59) {
      precision_flag = decodeTelegram(data);
      displayPrecisionMessage();
    }

    sec = 0;
    data = 0;
  }
  tlastBit = m;

  bit = (t > 150) ? 1 : 0;
  Serial.print(bit);

  // plot horizontal bar
  tft.fillRect(14 + 5 * sec, 54, 3, 3, bit ? ILI9341_YELLOW : ILI9341_PURPLE);
  data = ( data >> 1) | ((uint64_t)bit << 58);

  sec++;
  if (sec > 59) { // just to prevent accidents with weak signals ;-)
    sec = 0;
  }
  return bit;
}

void detectBit() {
  static float dcf_threshold_last = 1000;
  static unsigned long secStart = 0;

  if ( dcf_threshold <= dcf_threshold_last)
  {
    if (secStart == 0) {
      secStart = millis();
    }
  }

  else {
    unsigned long t = millis() - secStart;
    if ((secStart > 0) && (t > 90)) {
      int bit = decode(t);
      
      tft.fillRect(291, 5, 18, 18, ILI9341_BLACK);
      tft.setFont(Arial_12);
      tft.setTextColor(ILI9341_WHITE);
      tft.setCursor(295, 8);
      tft.print(bit);
    }
    secStart = 0;
  }
  dcf_threshold_last = dcf_threshold;
}


void spectrum() { // spectrum analyser code by rheslip - modified

  static int barm [512];

  for (unsigned int x = 2; x < FFT_points / 2; x++) {
    int bar = abs(myFFT.output[x]) * (int)(displayscale * 2.0);
    if (bar > 175) bar = 175;

    // this is a very simple first order IIR filter to smooth the reaction of the bars
    bar = 0.05 * bar + 0.95 * barm[x];
    tft.drawPixel(x / 2 + 10, 210 - barm[x], ILI9341_BLACK);
    tft.drawPixel(x / 2 + 10, 210 - bar, ILI9341_WHITE);
    barm[x] = bar;
  }
} // end void spectrum



int setI2SFreq(int freq) {
  typedef struct {
    uint8_t mult;
    uint16_t div;
  } tmclk;

  const int numfreqs = 14;
  const int samplefreqs[numfreqs] = { 8000, 11025, 16000, 22050, 32000, 44100, (int)44117.64706 , 48000, 88200, (int)44117.64706 * 2, 96000, 176400, (int)44117.64706 * 4, 192000};

#if (F_PLL==16000000)
  const tmclk clkArr[numfreqs] = {{16, 125}, {148, 839}, {32, 125}, {145, 411}, {64, 125}, {151, 214}, {12, 17}, {96, 125}, {151, 107}, {24, 17}, {192, 125}, {127, 45}, {48, 17}, {255, 83} };
#elif (F_PLL==72000000)
  const tmclk clkArr[numfreqs] = {{32, 1125}, {49, 1250}, {64, 1125}, {49, 625}, {128, 1125}, {98, 625}, {8, 51}, {64, 375}, {196, 625}, {16, 51}, {128, 375}, {249, 397}, {32, 51}, {185, 271} };
#elif (F_PLL==96000000)
  const tmclk clkArr[numfreqs] = {{8, 375}, {73, 2483}, {16, 375}, {147, 2500}, {32, 375}, {147, 1250}, {2, 17}, {16, 125}, {147, 625}, {4, 17}, {32, 125}, {151, 321}, {8, 17}, {64, 125} };
#elif (F_PLL==120000000)
  const tmclk clkArr[numfreqs] = {{32, 1875}, {89, 3784}, {64, 1875}, {147, 3125}, {128, 1875}, {205, 2179}, {8, 85}, {64, 625}, {89, 473}, {16, 85}, {128, 625}, {178, 473}, {32, 85}, {145, 354} };
#elif (F_PLL==144000000)
  const tmclk clkArr[numfreqs] = {{16, 1125}, {49, 2500}, {32, 1125}, {49, 1250}, {64, 1125}, {49, 625}, {4, 51}, {32, 375}, {98, 625}, {8, 51}, {64, 375}, {196, 625}, {16, 51}, {128, 375} };
#elif (F_PLL==168000000)
  const tmclk clkArr[numfreqs] = {{32, 2625}, {21, 1250}, {64, 2625}, {21, 625}, {128, 2625}, {42, 625}, {8, 119}, {64, 875}, {84, 625}, {16, 119}, {128, 875}, {168, 625}, {32, 119}, {189, 646} };
#elif (F_PLL==180000000)
  const tmclk clkArr[numfreqs] = {{46, 4043}, {49, 3125}, {73, 3208}, {98, 3125}, {183, 4021}, {196, 3125}, {16, 255}, {128, 1875}, {107, 853}, {32, 255}, {219, 1604}, {214, 853}, {64, 255}, {219, 802} };
#elif (F_PLL==192000000)
  const tmclk clkArr[numfreqs] = {{4, 375}, {37, 2517}, {8, 375}, {73, 2483}, {16, 375}, {147, 2500}, {1, 17}, {8, 125}, {147, 1250}, {2, 17}, {16, 125}, {147, 625}, {4, 17}, {32, 125} };
#elif (F_PLL==216000000)
  const tmclk clkArr[numfreqs] = {{32, 3375}, {49, 3750}, {64, 3375}, {49, 1875}, {128, 3375}, {98, 1875}, {8, 153}, {64, 1125}, {196, 1875}, {16, 153}, {128, 1125}, {226, 1081}, {32, 153}, {147, 646} };
#elif (F_PLL==240000000)
  const tmclk clkArr[numfreqs] = {{16, 1875}, {29, 2466}, {32, 1875}, {89, 3784}, {64, 1875}, {147, 3125}, {4, 85}, {32, 625}, {205, 2179}, {8, 85}, {64, 625}, {89, 473}, {16, 85}, {128, 625} };
#endif

  for (int f = 0; f < numfreqs; f++) {
    if ( freq == samplefreqs[f] ) {
      while (I2S0_MCR & I2S_MCR_DUF) ;
      I2S0_MDR = I2S_MDR_FRACT((clkArr[f].mult - 1)) | I2S_MDR_DIVIDE((clkArr[f].div - 1));
      return round(((float)F_PLL / 256.0) * clkArr[f].mult / clkArr[f].div); //return real freq
    }
  }
  return 0;
}

void check_processor() {
  if (second_timer.check() == 1) {
    Serial.print("Proc = ");
    Serial.print(AudioProcessorUsage());
    Serial.print(" (");
    Serial.print(AudioProcessorUsageMax());
    Serial.print("),  Mem = ");
    Serial.print(AudioMemoryUsage());
    Serial.print(" (");
    Serial.print(AudioMemoryUsageMax());
    Serial.println(")");
    /*      tft.fillRect(100,120,200,80,ILI9341_BLACK);
          tft.setCursor(10, 120);
          tft.setTextSize(2);
          tft.setTextColor(ILI9341_WHITE);
          tft.setFont(Arial_14);
          tft.print ("Proc = ");
          tft.setCursor(100, 120);
          tft.print (AudioProcessorUsage());
          tft.setCursor(180, 120);
          tft.print (AudioProcessorUsageMax());
          tft.setCursor(10, 150);
          tft.print ("Mem  = ");
          tft.setCursor(100, 150);
          tft.print (AudioMemoryUsage());
          tft.setCursor(180, 150);
          tft.print (AudioMemoryUsageMax());
    */
    AudioProcessorUsageMaxReset();
    AudioMemoryUsageMaxReset();
  }
} // END function check_processor

void displayClock() {

  uint8_t hour10 = hour() / 10 % 10;
  uint8_t hour1 = hour() % 10;
  uint8_t minute10 = minute() / 10 % 10;
  uint8_t minute1 = minute() % 10;
  uint8_t second10 = second() / 10 % 10;
  uint8_t second1 = second() % 10;
  uint8_t time_pos_shift = 26;
  tft.setFont(Arial_28);
  tft.setTextColor(ILI9341_WHITE);
  uint8_t dp = 14;

  if (mesz != mesz_old && mesz >= 0) {
    tft.setTextColor(ILI9341_ORANGE);
    tft.setFont(Arial_16);    
    tft.setCursor(pos_x_date, pos_y_date+20);
    tft.fillRect(pos_x_date, pos_y_date+20, 150-pos_x_date, 20, ILI9341_BLACK);
    tft.printf((mesz==0)?"(CET)":"(CEST)");
  }

  tft.setFont(Arial_28);
  tft.setTextColor(ILI9341_WHITE);

  // set up ":" for time display
  if (!timeflag) {
    tft.setCursor(pos_x_time + 2 * time_pos_shift, pos_y_time);
    tft.print(":");
    tft.setCursor(pos_x_time + 4 * time_pos_shift + dp, pos_y_time);
    tft.print(":");
    tft.setCursor(pos_x_time + 7 * time_pos_shift + 2 * dp, pos_y_time);
    //      tft.print("UTC");
  }

  if (hour10 != hour10_old || !timeflag) {
    tft.setCursor(pos_x_time, pos_y_time);
    tft.fillRect(pos_x_time, pos_y_time, time_pos_shift, time_pos_shift + 2, ILI9341_BLACK);
    if (hour10) tft.print(hour10);  // do not display, if zero
  }
  if (hour1 != hour1_old || !timeflag) {
    tft.setCursor(pos_x_time + time_pos_shift, pos_y_time);
    tft.fillRect(pos_x_time  + time_pos_shift, pos_y_time, time_pos_shift, time_pos_shift + 2, ILI9341_BLACK);
    tft.print(hour1);  // always display
  }
  if (minute1 != minute1_old || !timeflag) {
    tft.setCursor(pos_x_time + 3 * time_pos_shift + dp, pos_y_time);
    tft.fillRect(pos_x_time  + 3 * time_pos_shift + dp, pos_y_time, time_pos_shift, time_pos_shift + 2, ILI9341_BLACK);
    tft.print(minute1);  // always display
  }
  if (minute10 != minute10_old || !timeflag) {
    tft.setCursor(pos_x_time + 2 * time_pos_shift + dp, pos_y_time);
    tft.fillRect(pos_x_time  + 2 * time_pos_shift + dp, pos_y_time, time_pos_shift, time_pos_shift + 2, ILI9341_BLACK);
    tft.print(minute10);  // always display
  }
  if (second10 != second10_old || !timeflag) {
    tft.setCursor(pos_x_time + 4 * time_pos_shift + 2 * dp, pos_y_time);
    tft.fillRect(pos_x_time  + 4 * time_pos_shift + 2 * dp, pos_y_time, time_pos_shift, time_pos_shift + 2, ILI9341_BLACK);
    tft.print(second10);  // always display
  }
  if (second1 != second1_old || !timeflag) {
    tft.setCursor(pos_x_time + 5 * time_pos_shift + 2 * dp, pos_y_time);
    tft.fillRect(pos_x_time  + 5 * time_pos_shift + 2 * dp, pos_y_time, time_pos_shift, time_pos_shift + 2, ILI9341_BLACK);
    tft.print(second1);  // always display
  }

  hour1_old = hour1;
  hour10_old = hour10;
  minute1_old = minute1;
  minute10_old = minute10;
  second1_old = second1;
  second10_old = second10;
  mesz_old = mesz;
  timeflag = 1;

} // end function displayTime

void displayDate() {
  char string99 [20];
  tft.fillRect(pos_x_date, pos_y_date, 320 - pos_x_date, 20, ILI9341_BLACK); // erase old string
  tft.setTextColor(ILI9341_ORANGE);
  tft.setFont(Arial_16);
  tft.setCursor(pos_x_date, pos_y_date);
  //  Date: %s, %d.%d.20%d P:%d %d", Days[weekday-1], day, month, year
  sprintf(string99, "%s, %02d.%02d.%04d", Days[weekday()], day(), month(), year());
  tft.print(string99);
} // end function displayDate