src/Device/Parser.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_DEVICE_PARSER_HPP
  25 #define XCSOAR_DEVICE_PARSER_HPP
  26
  27 #include "Math/fixed.hpp"
  28
  29 struct NMEAInfo;
  30 struct BrokenDateTime;
  31 class NMEAInputLine;
  32 struct GeoPoint;
  33 struct BrokenDate;
  34
  35 class NMEAParser
  36 {
  37   bool ignore_checksum;
  38   static int start_day;
  39   fixed last_time;
  40
  41 public:
  42   bool real;
  43
  44   bool use_geoid;
  45
  46 public:
  47   NMEAParser(bool ignore_checksum = false);
  48
  49   /**
  50    * Resets the NMEAParser
  51    */
  52   void Reset();
  53
  54   void SetReal(bool _real) {
  55     real = _real;
  56   }
  57
  58   void SetIgnoreChecksum(bool _ignore_checksum) {
  59     ignore_checksum = _ignore_checksum;
  60   }
  61
  62   void DisableGeoid() {
  63     use_geoid = false;
  64   }
  65
  66   /**
  67    * Parses a provided NMEA String into a NMEA_INFO struct
  68    * @param line NMEA string
  69    * @param info NMEA_INFO output struct
  70    * @return Parsing success
  71    */
  72   bool ParseLine(const char *line, NMEAInfo &info);
  73
  74 public:
  75   /**
  76    * Calculates the checksum of the provided NMEA string and
  77    * compares it to the provided checksum
  78    * @param String NMEA string
  79    * @return True if checksum correct
  80    */
  81   static bool NMEAChecksum(const char *string);
  82
  83   /**
  84    * Checks whether time has advanced since last call and
  85    * updates the last_time reference if necessary
  86    * @return True if time has advanced since last call
  87    */
  88   static bool TimeHasAdvanced(fixed this_time, fixed &last_time, NMEAInfo &info);
  89
  90   /**
  91    * Calculates a seconds-based FixTime and corrects it
  92    * in case over passing the UTC midnight mark
  93    * @param FixTime NMEA format fix time (HHMMSS)
  94    * @param info NMEA_INFO struct to parse into
  95    * @return Seconds-based FixTime
  96    */
  97   static fixed TimeModify(fixed fix_time, BrokenDateTime &date_time,
  98                           bool date_available);
  99
 100   static bool ReadGeoPoint(NMEAInputLine &line, GeoPoint &value_r);
 101
 102   static bool ReadDate(NMEAInputLine &line, BrokenDate &date);
 103
 104 private:
 105
 106   /**
 107    * Verifies the given fix time.  If it is smaller than LastTime, but
 108    * within a certain tolerance, the LastTime is returned, otherwise
 109    * the specified time is returned without modification.
 110    *
 111    * This is used to reduce quirks when the time stamps in GPGGA and
 112    * GPRMC are off by a second.  Without this workaround, XCSoar loses
 113    * the GPS fix every now and then, because GPRMC is ignored most of
 114    * the time.
 115    */
 116   gcc_pure
 117   fixed TimeAdvanceTolerance(fixed time) const;
 118
 119   /**
 120    * Checks whether time has advanced since last call and
 121    * updates the GPS_info if necessary
 122    * @param ThisTime Current time
 123    * @param info NMEA_INFO struct to update
 124    * @return True if time has advanced since last call
 125    */
 126   bool TimeHasAdvanced(fixed this_time, NMEAInfo &info);
 127
 128   /**
 129    * Parses a GLL sentence
 130    *
 131    * @param line A NMEAInputLine instance that can be used for parsing
 132    * @param info NMEA_INFO struct to parse into
 133    * @return Parsing success
 134    */
 135   bool GLL(NMEAInputLine &line, NMEAInfo &info);
 136
 137   /**
 138    * Parses a GGA sentence
 139    *
 140    * @param line A NMEAInputLine instance that can be used for parsing
 141    * @param info NMEA_INFO struct to parse into
 142    * @return Parsing success
 143    */
 144   bool GGA(NMEAInputLine &line, NMEAInfo &info);
 145
 146   /**
 147    * Parses a GSA sentence
 148    *
 149    * @param line A NMEAInputLine instance that can be used for parsing
 150    * @param info NMEA_INFO struct to parse into
 151    * @return Parsing success
 152    */
 153   bool GSA(NMEAInputLine &line, NMEAInfo &info);
 154
 155   /**
 156    * Parses a RMC sentence
 157    *
 158    * @param line A NMEAInputLine instance that can be used for parsing
 159    * @param info NMEA_INFO struct to parse into
 160    * @return Parsing success
 161    */
 162   bool RMC(NMEAInputLine &line, NMEAInfo &info);
 163
 164   /**
 165    * Parses a PGRMZ sentence (Garmin proprietary).
 166    *
 167    * @param line A NMEAInputLine instance that can be used for parsing
 168    * @param info NMEA_INFO struct to parse into
 169    * @return Parsing success
 170    */
 171   bool RMZ(NMEAInputLine &line, NMEAInfo &info);
 172
 173   /**
 174    * Parses a PTAS1 sentence (Tasman Instruments proprietary).
 175    *
 176    * @param line A NMEAInputLine instance that can be used for parsing
 177    * @param info NMEA_INFO struct to parse into
 178    * @return Parsing success
 179    */
 180   static bool PTAS1(NMEAInputLine &line, NMEAInfo &info);
 181 };
 182
 183 #endif