// RPi3 DCF77 Second/Minute Monitor
// 24.01.2018. Author: YT2FSG - Goran Stankovic dipl.ing.el.
// email: goranstank@gmail.com, web: http://www.qsl.net/yt2fsg
//
// gcc -Wall -o dcf774 dcf77.c -l wiringPi
// sudo ./dcf77
//
// "0" =  7...13 
// "1" = 17...23
// sec = 90...105
// sync= 195...205

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>

#include <wiringPi.h>
#include <wiringPiSPI.h>

#define	TRUE	            (1==1)
#define	FALSE	            (!TRUE)
#define CHAN_CONFIG_SINGLE  8
#define CHAN_CONFIG_DIFF    0

char vr[80]={0};
char min, hour, day, d_v, mon, year, p1, p2, p3, zon, zlb;
char *d_vv[8]={"   ","Pon","Uto","Sre","Cet","Pet","Sub","Ned"};
char *zl[2]  ={"Zimsko","Letnje"};
char *utc[4] ={"UTC  ","UTC+1","UTC+2","UTC+3"};

char *amon[2]={"Second","Minute"};
char *usage  = "Usage: dcf77 [-s] [-m]";
// -s   = sekund monitor
// -m   = minut monitor
int moni=0;

char parity(int start, int end)
{
  int i;
  char par=0;
  for (i=start; i<=end; i++)
  {
	par = par ^ vr[i];
  }
  return par;
}

void decode(void)
{
  zlb = vr[16];
  zon = vr[18]+vr[17]*2;
  min = vr[21]+vr[22]*2+vr[23]*4+vr[24]*8+vr[25]*10+vr[26]*20+vr[27]*40;
  hour= vr[29]+vr[30]*2+vr[31]*4+vr[32]*8+vr[33]*10+vr[34]*20;
  day = vr[36]+vr[37]*2+vr[38]*4+vr[39]*8+vr[40]*10+vr[41]*20;
  d_v = vr[42]+vr[43]*2+vr[44]*4;
  mon = vr[45]+vr[46]*2+vr[47]*4+vr[48]*8+vr[49]*10;
  year= vr[50]+vr[51]*2+vr[52]*4+vr[53]*8+vr[54]*10+vr[55]*20+vr[56]*40+vr[57]*80;
}


int main (int argc, char *argv [])
{
    if (argc < 2)
    {
        fprintf (stderr, "%s\n", usage) ;
        return 1 ;
    }
    if((strcasecmp (argv [1], "-s") == 0) ){
        moni = 1;}
    else if (strcasecmp (argv [1], "-m") == 0){
        moni = 2;}
    else { moni = 2; }

	wiringPiSetup () ;
	pinMode (0, INPUT) ;	// BCM 17 = GPIO 0 = pin 11

    unsigned char sec=0, nf=0, pf=0;
    int in, cp=0, cn=0;
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    printf("*** RPi3 DCF77 - %s Monitor ***\n",amon[moni-1]);
    printf("by: YT2FSG - Goran Stankovic dipl.ing.el. (goranstank@gmail.com)\n\n");

if (moni==1)
{
    printf("     0       100       200       300       400       500       600       700       800       900      1000 ms\n");
    printf("     |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   \n");
}
else if (moni==2)
{
    printf("0        10        20        30        40        50      58 \n");
    printf("|    |    |    |    |    |    |    |    |    |    |    |  | \n");
    printf("               |1122||Minut 1| Sat 2| Dan |d||Mes.|Godina 3 \n");
    printf("M--------------RAZZAS1248124P124812P1248121241248112481248P \n");
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  while (1)
  {
    in = digitalRead(0);
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   if (in==0)
   {
      if (moni==1)
      {
	if (nf==0)
	{
		nf=1;
		printf("\n%02d : ", sec);
		sec++;
	}
	printf("*");
	pf=0;
     }
     else if (moni==2)
     {
	  if (cp > 170)
	  {
	    if (sec==59)
	    {
	    	decode();
	    	printf(" %02d.%02d.20%d. %02d:%02d:00 %s - %s %s \n",day,mon,year,hour,min, d_vv[d_v], zl[zlb], utc[zon]);
	    }
	    else
	    {
		printf("\n");
	    }
	    sec=0;
	  }
     }
     cp=0;
     cn++;
     if (cn>100)
     {
	cn=0;
	printf("\n");
     }

  }
  else
  {
     if (moni==1)
     {
	printf("-");
	if ((cp+cn) > 98)
	{
	  if (pf==0)
	  {
	    pf=1;
	    printf("\nSync ");
	    sec++;
	  }
	  if (cp > 150)
	  {
	    sec=0;
	  }
	}
	nf=0;
     }
     else if (moni==2)
     {
	if ((cn > 7)&&(cn < 13))
	{
	    vr[sec]=0;
	    sec++;
	    printf("-");
	}
	else if ((cn > 17)&&(cn < 23))
	{
	    vr[sec]=1;
	    sec++;
	    printf("*");
	}
    }
     cn=0;
     cp++;
     if (cp>200)
     {
	cp=0;
	printf("\n");
     }
  }
    delay(10);  //10ms
 } 
  return 0;
}