src/Device/Driver/Volkslogger/Parser.cpp

   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 #include "Internal.hpp"
  25 #include "NMEA/Info.hpp"
  26 #include "NMEA/InputLine.hpp"
  27 #include "NMEA/Checksum.hpp"
  28
  29 // RMN: Volkslogger
  30 // Source data:
  31 // $PGCS,1,0EC0,FFF9,0C6E,02*61
  32 // $PGCS,1,0EC0,FFFA,0C6E,03*18
  33 static bool
  34 vl_PGCS1(NMEAInputLine &line, NMEAInfo &info)
  35 {
  36   if (line.Read(1) != 1)
  37     return false;
  38
  39   /* pressure sensor */
  40   line.Skip();
  41
  42   // four characers, hex, barometric altitude
  43   unsigned u_altitude;
  44   if (line.ReadHexChecked(u_altitude)) {
  45     int altitude(u_altitude);
  46     if (altitude > 60000)
  47       /* Assuming that altitude has wrapped around.  60 000 m occurs
  48          at QNH ~2000 hPa */
  49       altitude -= 65535;
  50
  51     info.ProvidePressureAltitude(fixed(altitude));
  52   }
  53
  54   // ExtractParameter(String,ctemp,3);
  55   // four characters, hex, constant.  Value 1371 (dec)
  56
  57   // nSatellites = (int)(min(12,HexStrToDouble(ctemp, NULL)));
  58
  59   return false;
  60 }
  61
  62 bool
  63 VolksloggerDevice::ParseNMEA(const char *String, NMEAInfo &info)
  64 {
  65   if (!VerifyNMEAChecksum(String))
  66     return false;
  67
  68   NMEAInputLine line(String);
  69   char type[16];
  70   line.Read(type, 16);
  71
  72   if (StringIsEqual(type, "$PGCS"))
  73     return vl_PGCS1(line, info);
  74   else
  75     return false;
  76 }