Fix #253 - Add support for $GNGGA NMEA sentences for MSL altitude

barbeau · Jan 28, 2019 · 5b434e8 · 5b434e8
1 parent 01e6f0f
commit 5b434e8
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Showing 2 changed files with 14 additions and 4 deletions.
diff --git a/GPSTest/src/main/java/com/android/gpstest/util/GpsTestUtil.java b/GPSTest/src/main/java/com/android/gpstest/util/GpsTestUtil.java
@@ -320,27 +320,29 @@ public static void writeGnssMeasurementToLog(GnssMeasurement measurement) {
     }
 
     /**
-     * Given a $GPGGA or $GNGNS NMEA sentence, return the altitude above mean sea level (geoid
+     * Given a $GPGGA, $GNGNS, or $GNGGA NMEA sentence, return the altitude above mean sea level (geoid
      * altitude),
      * or null if the altitude can't be parsed.
      *
      * Example inputs are:
      * $GPGGA,032739.0,2804.732835,N,08224.639709,W,1,08,0.8,19.2,M,-24.0,M,,*5B
      * $GNGNS,015002.0,2804.733672,N,08224.631117,W,AAN,09,1.1,78.9,-24.0,,*23
+     * $GNGGA,172814.00,2803.208136,N,08225.981423,W,1,08,1.1,-19.7,M,-24.8,M,,*5F
      *
      * Example outputs would be:
      * 19.2
      * 78.9
+     * -19.7
      *
-     * @param nmeaSentence a $GPGGA or $GNGNS NMEA sentence
+     * @param nmeaSentence a $GPGGA, $GNGNS, or $GNGGA NMEA sentence
      * @return the altitude above mean sea level (geoid altitude), or null if altitude can't be
      * parsed
      */
     public static Double getAltitudeMeanSeaLevel(String nmeaSentence) {
         final int ALTITUDE_INDEX = 9;
         String[] tokens = nmeaSentence.split(",");
 
-        if (nmeaSentence.startsWith("$GPGGA") || nmeaSentence.startsWith("$GNGNS")) {
+        if (nmeaSentence.startsWith("$GPGGA") || nmeaSentence.startsWith("$GNGNS") || nmeaSentence.startsWith("$GNGGA")) {
             String altitude;
             try {
                 altitude = tokens[ALTITUDE_INDEX];
@@ -361,7 +363,7 @@ public static Double getAltitudeMeanSeaLevel(String nmeaSentence) {
                 return null;
             }
         } else {
-            Log.w(TAG, "Input must be a $GPGGA or $GNGNS NMEA: " + nmeaSentence);
+            Log.w(TAG, "Input must be $GPGGA, $GNGNS, or $GNGGA NMEA: " + nmeaSentence);
             return null;
         }
     }

diff --git a/GPSTest/src/test/java/com/android/gpstest/GpsTestUtilTest.java b/GPSTest/src/test/java/com/android/gpstest/GpsTestUtilTest.java
@@ -35,13 +35,21 @@ public void testGetAltitudeFromNmea() {
                 = "$GPGGA,032739.0,2804.732835,N,08224.639709,W,1,08,0.8,19.2,M,-24.0,M,,*5B";
         final String gnssSentence
                 = "$GNGNS,015002.0,2804.733672,N,08224.631117,W,AAN,09,1.1,78.9,-24.0,,*23";
+        final String gnGga1 = "$GNGGA,114926.00,3206.341435,N,11850.092448,E,1,11,0.9,19.9,M,2.2,M,,*7E";
+        final String gnGga2 = "$GNGGA,172814.00,2803.208136,N,08225.981423,W,1,08,1.1,-19.7,M,-24.8,M,,*5F";
 
         altitude = GpsTestUtil.getAltitudeMeanSeaLevel(gpsSentence);
         assertEquals(19.2d, altitude);
 
         altitude = GpsTestUtil.getAltitudeMeanSeaLevel(gnssSentence);
         assertEquals(78.9d, altitude);
 
+        altitude = GpsTestUtil.getAltitudeMeanSeaLevel(gnGga1);
+        assertEquals(19.9d, altitude);
+
+        altitude = GpsTestUtil.getAltitudeMeanSeaLevel(gnGga2);
+        assertEquals(-19.7d, altitude);
+
         final String badGnssSentence
                 = "$GNGNS,015002.0,2804.733672,N,08224.631117,W,AAN,09,1.1,BAD,-24.0,,*23";
         altitude = GpsTestUtil.getAltitudeMeanSeaLevel(badGnssSentence);