1 files changed, 135 insertions, 0 deletions
diff --git a/wwvb.c b/wwvb.c
new file mode 100644
index 0000000..12fc4d5
--- /dev/null
+++ b/wwvb.c
@@ -0,0 +1,135 @@
+#include "project.h"
+
+
+static void wwvb_make_bits (UTC u, uint8_t *b)
+{
+
+  bzero (b, 60);
+
+  b[0]=2;
+  bcd_set (b, 1, 3, u.minute/10);
+  b[4]=0;
+  bcd_set (b, 5, 8, u.minute);
+  b[9]=2;
+  b[10]=0;
+  b[11]=0;
+  bcd_set (b, 12, 13, u.hour/10);
+  b[14]=0;
+  bcd_set (b, 15, 18, u.hour);
+  b[19]=2;
+  b[20]=0;
+  b[21]=0;
+  bcd_set (b, 22, 23, u.jday/100);
+  b[24]=0;
+  bcd_set (b, 25, 28, u.jday/10);
+  b[29]=2;
+  bcd_set (b, 30, 33, u.jday);
+  b[34]=0;
+  b[35]=0;
+  b[36]=1; //DUT1+
+  b[37]=0;
+  b[38]=1; //DUT1+
+  b[39]=2;
+
+  b[40]=0; //DUT1=0
+  b[41]=0;
+  b[42]=0;
+  b[43]=0;
+
+  b[44]=0;
+
+
+
+
+
+  bcd_set (b, 45, 48, (u.year % 100)/10);
+  b[49]=2;
+  bcd_set (b, 50, 53, (u.year % 100));
+
+  b[55]=!(u.year % 400) ^ !(u.year % 100) ^ !(u.year%4);
+
+
+  b[56]=0; //no leap second
+
+  b[57]=0; //no DST
+  b[58]=0; 
+
+  b[59]=2;
+
+}
+
+static void process_bits (uint8_t *b)
+{
+  UTC u;
+
+if (b[0]!=2) return;
+if (b[4]) return;
+if (b[9]!=2) return;
+if (b[10]) return;
+if (b[11]) return;
+if (b[14]) return;
+if (b[19]!=2) return;
+if (b[20]) return;
+if (b[21]) return;
+if (b[24]) return;
+if (b[29]!=2) return;
+if (b[34]) return;
+if (b[35]) return;
+if (b[39]!=2) return;
+if (b[59]!=2) return;
+
+  if (check_parity (b, 12, 18, !b[36])) return;
+  if (check_parity (b, 1, 8, !b[37])) return;
+
+  u.jday = bcd(b,22,23);
+  u.jday*=10;
+  u.jday += bcd(b,25,28);
+  u.jday*=10;
+  u.jday+=bcd(b,30,33);
+  u.year = bcd (b, 41, 48);
+  u.hour = bcd (b, 12, 13);
+  u.hour*=10;
+  u.hour += bcd (b, 15, 18);
+  u.minute = bcd (b, 1, 3);
+  u.minute*=10;
+  u.minute += bcd (b, 5, 8);
+  u.wday=bcd(b,50,52);
+
+  u.second = 0;
+  u.nanosecond = 0;
+
+
+
+  printf ("JJY: decoded %02d-%03d (DOW %d)  %02d:%02d\r\n", u.year, u.jday,u.wday, u.hour, u.minute);
+}
+
+
+
+void wwvb_make_stream (uint8_t *v, UTC u)
+{
+  unsigned s;
+  uint8_t b[60];
+  uint8_t *pb;
+
+  wwvb_make_bits (u, b);
+  process_bits ( b);
+
+  bzero (v, 600);
+
+  for (s = 0, pb = b; s < 60; ++s, v += 10, ++pb) {
+	   memset(v,0,10);
+   switch(*pb) {
+	case 0:
+	   memset(v+8,1,2);
+  	   break;
+	case 1:
+	   memset(v+5,1,5);
+  	   break;
+	case 2:
+	   memset(v+2,1,8);
+  	   break;
+    }
+  }
+}
+
+