Add $--ZDA sentences

* Expand LDLIBS var in Makefile
* Add parser zda
* Extend sentence_id
* Add example

example.c

@@ -107,6 +107,24 @@ int main(void)
                }
             } break;
 
+            case MINMEA_SENTENCE_ZDA: {
+                struct minmea_sentence_zda frame;
+                if (minmea_parse_zda(&frame, line)) {
+                    printf(INDENT_SPACES "$xxZDA: %d:%d:%d %02d.%02d.%d UTC%+03d:%02d\n",
+                           frame.time.hours,
+                           frame.time.minutes,
+                           frame.time.seconds,
+                           frame.date.day,
+                           frame.date.month,
+                           frame.date.year,
+                           frame.hour_offset,
+                           frame.minute_offset);
+                }
+                else {
+                    printf(INDENT_SPACES "$xxZDA sentence is not parsed\n");
+                }
+            } break;
+
             case MINMEA_INVALID: {
                 printf(INDENT_SPACES "$xxxxx sentence is not valid\n");
             } break;

minmea.c

@@ -372,6 +372,8 @@ enum minmea_sentence_id minmea_sentence_id(const char *sentence, bool strict)
         return MINMEA_SENTENCE_GSV;
     if (!strcmp(type+2, "VTG"))
         return MINMEA_SENTENCE_VTG;
+    if (!strcmp(type+2, "ZDA"))
+        return MINMEA_SENTENCE_ZDA;
 
     return MINMEA_UNKNOWN;
 }
@@ -584,6 +586,32 @@ bool minmea_parse_vtg(struct minmea_sentence_vtg *frame, const char *sentence)
     return true;
 }
 
+bool minmea_parse_zda(struct minmea_sentence_zda *frame, const char *sentence)
+{
+  // $GPZDA,201530.00,04,07,2002,00,00*60
+  char type[6];
+
+  if(!minmea_scan(sentence, "tTiiiii",
+          type,
+          &frame->time,
+          &frame->date.day,
+          &frame->date.month,
+          &frame->date.year,
+          &frame->hour_offset,
+          &frame->minute_offset))
+      return false;
+  if (strcmp(type+2, "ZDA"))
+      return false;
+
+  // check offsets
+  if (abs(frame->hour_offset) > 13 ||
+      frame->minute_offset > 59 ||
+      frame->minute_offset < 0)
+      return false;
+
+  return true;
+}
+
 int minmea_gettime(struct timespec *ts, const struct minmea_date *date, const struct minmea_time *time_)
 {
     if (date->year == -1 || time_->hours == -1)

minmea.h

@@ -32,6 +32,7 @@ enum minmea_sentence_id {
     MINMEA_SENTENCE_GST,
     MINMEA_SENTENCE_GSV,
     MINMEA_SENTENCE_VTG,
+    MINMEA_SENTENCE_ZDA,
 };
 
 struct minmea_float {
@@ -152,6 +153,13 @@ struct minmea_sentence_vtg {
     enum minmea_faa_mode faa_mode;
 };
 
+struct minmea_sentence_zda {
+    struct minmea_time time;
+    struct minmea_date date;
+    int hour_offset;
+    int minute_offset;
+};
+
 /**
  * Calculate raw sentence checksum. Does not check sentence integrity.
  */
@@ -195,6 +203,7 @@ bool minmea_parse_gll(struct minmea_sentence_gll *frame, const char *sentence);
 bool minmea_parse_gst(struct minmea_sentence_gst *frame, const char *sentence);
 bool minmea_parse_gsv(struct minmea_sentence_gsv *frame, const char *sentence);
 bool minmea_parse_vtg(struct minmea_sentence_vtg *frame, const char *sentence);
+bool minmea_parse_zda(struct minmea_sentence_zda *frame, const char *sentence);
 
 /**
  * Convert GPS UTC date/time representation to a UNIX timestamp.