(1) New High Precision parseDegrees() supports high-end Leica receivers with sub-centimeter accuracy, (2) Integral lat and long changed to degrees + billionths, (3) Allow time and date to be extracted from GPGGA and GPRMC even without fix. (4) Clean up spurious comments, (5) Library version now a string (0.92), (6) Improved KitchenSink sample, (7) Rewrote examples to support slightly changed API.

Author: mikalhart

TinyGPS++.cpp

@@ -36,11 +36,11 @@ TinyGPSPlus::TinyGPSPlus()
   ,  curSentenceType(GPS_SENTENCE_OTHER)
   ,  curTermNumber(0)
   ,  curTermOffset(0)
-  ,  gpsDataGood(false)
+  ,  sentenceHasFix(false)
   ,  customElts(0)
   ,  customCandidates(0)
   ,  encodedCharCount(0)
-  ,  goodSentenceCount(0)
+  ,  sentencesWithFixCount(0)
   ,  failedChecksumCount(0)
   ,  passedChecksumCount(0)
 {
@@ -81,7 +81,7 @@ bool TinyGPSPlus::encode(char c)
     parity = 0;
     curSentenceType = GPS_SENTENCE_OTHER;
     isChecksumTerm = false;
-    gpsDataGood = false;
+    sentenceHasFix = false;
     return false;
 
   default: // ordinary characters
@@ -127,21 +127,26 @@ int32_t TinyGPSPlus::parseDecimal(const char *term)
 
 // static
 // Parse degrees in that funny NMEA format DDMM.MMMM
-uint32_t TinyGPSPlus::parseDegrees(const char *term)
+void TinyGPSPlus::parseDegrees(const char *term, int16_t &degrees, uint32_t &billionths)
 {
-  unsigned long leftOfDecimal = atol(term);
-  unsigned long _100000thsOfMinute = (leftOfDecimal % 100UL) * 100000UL;
-  while (isdigit(*term)) ++term;
+  uint32_t leftOfDecimal = (uint32_t)atol(term);
+  uint16_t minutes = (uint16_t)(leftOfDecimal % 100);
+  uint32_t multiplier = 10000000UL;
+  uint32_t tenMillionthsOfMinutes = minutes * multiplier;
+
+  degrees = (int16_t)(leftOfDecimal / 100);
+
+  while (isdigit(*term))
+    ++term;
+
   if (*term == '.')
-  {
-    unsigned long mult = 10000;
     while (isdigit(*++term))
     {
-      _100000thsOfMinute += mult * (*term - '0');
-      mult /= 10;
+      multiplier /= 10;
+      tenMillionthsOfMinutes += (*term - '0') * multiplier;
     }
-  }
-  return (leftOfDecimal / 100) * 1000000 + (_100000thsOfMinute + 3) / 6;
+
+  billionths = (5 * tenMillionthsOfMinutes + 1) / 3;
 }
 
 #define COMBINE(sentence_type, term_number) (((unsigned)(sentence_type) << 5) | term_number)
@@ -150,34 +155,38 @@ uint32_t TinyGPSPlus::parseDegrees(const char *term)
 // Returns true if new sentence has just passed checksum test and is validated
 bool TinyGPSPlus::endOfTermHandler()
 {
-  // If it's the checksum term, and the checksum checks out and it's got "good" data, then commit it
+  // If it's the checksum term, and the checksum checks out, commit
   if (isChecksumTerm)
   {
     byte checksum = 16 * fromHex(term[0]) + fromHex(term[1]);
     if (checksum == parity)
     {
       passedChecksumCount++;
-      if (gpsDataGood)
-      {
-        ++goodSentenceCount;
+      if (sentenceHasFix)
+        ++sentencesWithFixCount;
 
-        switch(curSentenceType)
+      switch(curSentenceType)
+      {
+      case GPS_SENTENCE_GPRMC:
+        date.commit();
+        time.commit();
+        if (sentenceHasFix)
         {
-        case GPS_SENTENCE_GPRMC:
-           date.commit();
-           time.commit();
            location.commit();
            speed.commit();
            course.commit();
-          break;
-        case GPS_SENTENCE_GPGGA:
-           time.commit();
-           location.commit();
-           altitude.commit();
-           satellites.commit();
-           hdop.commit();
-          break;
         }
+        break;
+      case GPS_SENTENCE_GPGGA:
+        time.commit();
+        if (sentenceHasFix)
+        {
+          location.commit();
+          altitude.commit();
+        }
+        satellites.commit();
+        hdop.commit();
+        break;
       }
 
       // Commit all custom listeners of this sentence type
@@ -220,7 +229,7 @@ bool TinyGPSPlus::endOfTermHandler()
       time.setTime(term);
       break;
     case COMBINE(GPS_SENTENCE_GPRMC, 2): // GPRMC validity
-      gpsDataGood = term[0] == 'A';
+      sentenceHasFix = term[0] == 'A';
       break;
     case COMBINE(GPS_SENTENCE_GPRMC, 3): // Latitude
     case COMBINE(GPS_SENTENCE_GPGGA, 2):
@@ -229,7 +238,7 @@ bool TinyGPSPlus::endOfTermHandler()
     case COMBINE(GPS_SENTENCE_GPRMC, 4): // N/S
     case COMBINE(GPS_SENTENCE_GPGGA, 3):
       if (term[0] == 'S')
-        location.newlat = -location.newlat;
+        location.iNewLatDegrees = -location.iNewLatDegrees;
       break;
     case COMBINE(GPS_SENTENCE_GPRMC, 5): // Longitude
     case COMBINE(GPS_SENTENCE_GPGGA, 4):
@@ -238,7 +247,7 @@ bool TinyGPSPlus::endOfTermHandler()
     case COMBINE(GPS_SENTENCE_GPRMC, 6): // E/W
     case COMBINE(GPS_SENTENCE_GPGGA, 5):
       if (term[0] == 'W')
-        location.newlng = -location.newlng;
+        location.iNewLngDegrees = -location.iNewLngDegrees;
       break;
     case COMBINE(GPS_SENTENCE_GPRMC, 7): // Speed (GPRMC)
       speed.set(term);
@@ -250,7 +259,7 @@ bool TinyGPSPlus::endOfTermHandler()
       date.setDate(term);
       break;
     case COMBINE(GPS_SENTENCE_GPGGA, 6): // Fix data (GPGGA)
-      gpsDataGood = term[0] > '0';
+      sentenceHasFix = term[0] > '0';
       break;
     case COMBINE(GPS_SENTENCE_GPGGA, 7): // Satellites used (GPGGA)
       satellites.set(term);
@@ -320,39 +329,44 @@ double TinyGPSPlus::courseTo(double lat1, double long1, double lat2, double long
 const char *TinyGPSPlus::cardinal(double course)
 {
   static const char* directions[] = {"N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE", "S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW"};
-
   int direction = (int)((course + 11.25f) / 22.5f);
   return directions[direction % 16];
 }
 
 void TinyGPSLocation::commit()
 {
-   ilat = newlat;
-   ilng = newlng;
+   iLatDegrees = iNewLatDegrees;
+   uLatBillionths = uNewLatBillionths;
+   iLngDegrees = iNewLngDegrees;
+   uLngBillionths = uNewLngBillionths;
    lastCommitTime = millis();
    valid = updated = true;
 }
 
 void TinyGPSLocation::setLatitude(const char *term)
 {
-   newlat = TinyGPSPlus::parseDegrees(term);
+   TinyGPSPlus::parseDegrees(term, iNewLatDegrees, uNewLatBillionths);
 }
 
 void TinyGPSLocation::setLongitude(const char *term)
 {
-   newlng = TinyGPSPlus::parseDegrees(term);
+   TinyGPSPlus::parseDegrees(term, iNewLngDegrees, uNewLngBillionths);
 }
 
 double TinyGPSLocation::lat()
 {
    updated = false;
-   return ilat / 1000000.0;
+   return iLatDegrees > 0 ? 
+      (iLatDegrees + uLatBillionths / 1000000000.0) :
+      (iLatDegrees - uLatBillionths / 1000000000.0);
 }
 
 double TinyGPSLocation::lng()
 {
    updated = false;
-   return ilng / 1000000.0;
+   return iLngDegrees > 0 ? 
+      (iLngDegrees + uLngBillionths / 1000000000.0) :
+      (iLngDegrees - uLngBillionths / 1000000000.0);
 }
 
 void TinyGPSDate::commit()

TinyGPS++.h

@@ -31,29 +31,14 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #endif
 #include <limits.h>
 
-#define _GPS_VERSION 1 // software version of this library
+#define _GPS_VERSION "0.92" // software version of this library
 #define _GPS_MPH_PER_KNOT 1.15077945
 #define _GPS_MPS_PER_KNOT 0.51444444
 #define _GPS_KMPH_PER_KNOT 1.852
 #define _GPS_MILES_PER_METER 0.00062137112
 #define _GPS_KM_PER_METER 0.001
 #define _GPS_FEET_PER_METER 3.2808399
 #define _GPS_MAX_FIELD_SIZE 15
-/*
-   Field       Type    Format    Source                   Notes
-   -----       ----    ------    ------                   -----
-   Time        u32     hhmmsscc  GPRMC.1 OR GPGGA.1       Decimal
-   RmcValid    bool    isvalid   GPRMC.2                  =='A'
-   Latitude:   i32     dmill     GPRMC.3/4 OR GPGGA 2/3   Degrees (N/S)
-   Longitude   i32     dmill     GPRMC.5/6 or GPGGA.4/5   Degrees (E/W)
-   Speed       u32     kn100     GPRMC.7                  Decimal
-   Course      u32     deg100    GPRMC.8                  Decimal
-   Date        u32     ddmmyy    GPRMC.9
-   FixValid    bool    isgood    GPGGA.6                  > '0'
-   Satellites  u8      sats      GPGGA.7                  Decimal
-   HDOP        u32     hdop100   GPGGA.8                  Decimal
-   Altitude    i32     cm        GPGGA.9                  Decimal
-*/
 
 struct TinyGPSLocation
 {
@@ -63,17 +48,21 @@ struct TinyGPSLocation
    bool isUpdated() const  { return updated; }
    uint32_t age() const    { return valid ? millis() - lastCommitTime : (uint32_t)ULONG_MAX; }
 
-   int32_t rawLat()        { updated = false; return ilat; }
-   int32_t rawLng()        { updated = false; return ilng; }
-   double  lat();
-   double  lng();
+   int16_t rawLatDegrees()     { updated = false; return iLatDegrees; }
+   int16_t rawLngDegrees()     { updated = false; return iLngDegrees; }
+   uint32_t rawLatBillionths() { updated = false; return uLatBillionths; }
+   uint32_t rawLngBillionths() { updated = false; return uLngBillionths; }
+   double lat();
+   double lng();
 
-   TinyGPSLocation() : valid(false), updated(false), ilat(0), ilng(0)
+   TinyGPSLocation() : valid(false), updated(false), 
+      iLatDegrees(0), iLngDegrees(0), uLatBillionths(0), uLngBillionths(0)
    {}
 
 private:
    bool valid, updated;
-   int32_t ilat, newlat, ilng, newlng;
+   int16_t iLatDegrees, iNewLatDegrees, iLngDegrees, iNewLngDegrees;
+   uint32_t uLatBillionths, uNewLatBillionths, uLngBillionths, uNewLngBillionths;
    uint32_t lastCommitTime;
    void commit();
    void setLatitude(const char *term);
@@ -233,19 +222,19 @@ class TinyGPSPlus
   TinyGPSInteger satellites;
   TinyGPSDecimal hdop;
 
-  static int libraryVersion() { return _GPS_VERSION; }
+  static const char *libraryVersion() { return _GPS_VERSION; }
 
   static double distanceBetween(double lat1, double long1, double lat2, double long2);
   static double courseTo(double lat1, double long1, double lat2, double long2);
   static const char *cardinal(double course);
 
   static int32_t parseDecimal(const char *term);
-  static uint32_t parseDegrees(const char *term);
+  static void parseDegrees(const char *term, int16_t &degrees, uint32_t &billionths);
 
-  uint32_t charsProcessed() const { return encodedCharCount; }
-  uint32_t goodSentences()  const { return goodSentenceCount; }
-  uint32_t failedChecksum() const { return failedChecksumCount; }
-  uint32_t passedChecksum() const { return passedChecksumCount; }
+  uint32_t charsProcessed()   const { return encodedCharCount; }
+  uint32_t sentencesWithFix() const { return sentencesWithFixCount; }
+  uint32_t failedChecksum()   const { return failedChecksumCount; }
+  uint32_t passedChecksum()   const { return passedChecksumCount; }
 
 private:
   enum {GPS_SENTENCE_GPGGA, GPS_SENTENCE_GPRMC, GPS_SENTENCE_OTHER};
@@ -257,7 +246,7 @@ class TinyGPSPlus
   uint8_t curSentenceType;
   uint8_t curTermNumber;
   uint8_t curTermOffset;
-  bool gpsDataGood;
+  bool sentenceHasFix;
 
   // custom element support
   friend class TinyGPSCustom;
@@ -267,7 +256,7 @@ class TinyGPSPlus
 
   // statistics
   uint32_t encodedCharCount;
-  uint32_t goodSentenceCount;
+  uint32_t sentencesWithFixCount;
   uint32_t failedChecksumCount;
   uint32_t passedChecksumCount;
 

examples/FullExample/FullExample.ino

@@ -66,7 +66,7 @@ void loop()
   printStr(gps.location.isValid() ? cardinalToLondon : "*** ", 6);
 
   printInt(gps.charsProcessed(), true, 6);
-  printInt(gps.goodSentences(), true, 10);
+  printInt(gps.sentencesWithFix(), true, 10);
   printInt(gps.failedChecksum(), true, 9);
   Serial.println();
 
@@ -156,4 +156,4 @@ static void printStr(const char *str, int len)
   for (int i=0; i<len; ++i)
     Serial.print(i<slen ? str[i] : ' ');
   smartDelay(0);
-}
+}

examples/KitchenSink/KitchenSink.ino

@@ -40,10 +40,14 @@ void loop()
     Serial.print(F("LOCATION   Fix Age="));
     Serial.print(gps.location.age());
     Serial.print(F("ms Raw Lat="));
-    Serial.print(gps.location.rawLat());
-    Serial.print(F(" Raw Long="));
-    Serial.print(gps.location.rawLng());
-    Serial.print(F(" Lat="));
+    Serial.print(gps.location.rawLatDegrees());
+    Serial.print(" and ");
+    Serial.print(gps.location.rawLatBillionths());
+    Serial.print(F(" billionths,  Raw Long="));
+    Serial.print(gps.location.rawLngDegrees());
+    Serial.print(".");
+    Serial.print(gps.location.rawLngBillionths());
+    Serial.print(F(" billionths,  Lat="));
     Serial.print(gps.location.lat(), 6);
     Serial.print(F(" Long="));
     Serial.println(gps.location.lng(), 6);
@@ -167,8 +171,8 @@ void loop()
 
     Serial.print(F("DIAGS      Chars="));
     Serial.print(gps.charsProcessed());
-    Serial.print(F(" Good-sentences="));
-    Serial.print(gps.goodSentences());
+    Serial.print(F(" Sentences-with-Fix="));
+    Serial.print(gps.sentencesWithFix());
     Serial.print(F(" Failed-checksum="));
     Serial.print(gps.failedChecksum());
     Serial.print(F(" Passed-checksum="));