nmea.h

Construct NMEA packet in GPS module

#ifndef NMEA_H
#define NMEA_H

/* #define SIM_MODE **/



#define MAX_NMEA_FIELD	 25
#define MAX_NMEA_BUFFER  300
#define MAX_NMEA_SENTENCE 82



/**
 *  Sentence strings.
 **/
#define NMEA_SENTENCE_START "$"
#define NMEA_SENTENCE_COMMA ","
#define NMEA_SENTENCE_CR    '0D'
#define NMEA_SENTENCE_LF    '0A'
#define NMEA_SENTENCE_ASTERISK "*"

#define NMEA_SENTENCE_DGPS_STATION_ID "0000"
#define NMEA_SENTENCE_DUMMY_CHECK_SUM "00"

#define NMEA_SENTENCE_NORTH "N"
#define NMEA_SENTENCE_SOUTH "S"
#define NMEA_SENTENCE_EAST  "E"
#define NMEA_SENTENCE_WEST  "W"

#define NMEA_UNITS_METERS   "M"

typedef enum _NMEA_E_W_N_S
{
  NMEA_EAST,
  NMEA_WEST,
  NMEA_NORTH,
  NMEA_SOUTH
} NMEA_E_W_N_S;



#define NMEA_SENTENCE_GPGGA "GPGGA"
#define NMEA_SENTENCE_GPGSV "GPGSV"
#define NMEA_SENTENCE_GPGSA "GPGSA"
#define NMEA_SENTENCE_GPVTG "GPVTG"
#define NMEA_SENTENCE_GPRMC "GPRMC"
#define NMEA_SENTENCE_GPZDA "GPZDA"


typedef enum _NMEA_STATUS
{
  NMEA_SUCCESS,
  NMEA_FAILED
} NMEA_STATUS;

typedef enum _NMEA_FIX_QUALITY
{
  NMEA_FIX_QUALITY_INVALID,
  NMEA_FIX_QUALITY_SPS
} NMEA_FIX_QUALITY;


typedef struct _NMEA_GGA_DATA
{
  double TimeOfFixUTC;          /* 0 */
  double Lat;                   /* 1 */
  int NorthSouth;               /* 2 */
  double Long;                  /* 3 */
  int EastWest;                 /* 4 */
  int FixQuality;               /* 5 */
  int NumberOfTrackingSV;       /* 6 */
  int HDOP;                     /* 7 */
  double Altitude;              /* 8 */
  int AltitudeUnits;            /* 9 */
  double HeightOfGeoid;         /* 10 Height of geoid above WGS84 ellipsoid */
  int GeoidUnits;               /* 11 */
  int TimeSinceLastDGPSFix;     /* 12 */
  int DGPSID;                   /* 13 */
} NMEA_GGA_DATA, *pNMEA_GGA_DATA;

typedef struct _SV_VIEW_DATA
{
  int Valid;                    /*  Does it contain data */
  int SatellitePRN;             /*  Satellite PRN  */
  int Elevation;                /*  Elevation, degrees */
  int Azimuth;                  /*  Azimuth */
  int SNR;                       
} SV_VIEW_DATA, *pSV_VIEW_DATA;

#define MAX_NMEA_SATELLITES_IN_VIEW 12

typedef struct _NMEA_GSV_DATA
{
  int NumberOfSentences;        /* 0 Number of sentences for full data */
  int SequenceNumber;           /* 1 */
  int NumberOfSatellites;       /* 2 */

  SV_VIEW_DATA SvViewData[MAX_NMEA_SATELLITES_IN_VIEW];

} NMEA_GSV_DATA, *pNMEA_GSV_DATA;

#define NMEA_TRUE_HEADING "T"
#define NMEA_MAG_HEADING  "M"
#define NMEA_KNOTS        "N"
#define NMEA_KILOS        "K"

typedef struct _NMEA_VTG_DATA
{
  double TrueHeading;
  double MagHeading;
  double GroundSpeedKnots;
  double GroundSpeedKilos;
} NMEA_VTG_DATA, *pNMEA_VTG_DATA;

#define NMEA_FIX_MODE_NO_FIX 1
#define NMEA_FIX_MODE_2D_FIX 2
#define NMEA_FIX_MODE_3D_FIX 3

#define NMEA_MODE_A_STR "A"
#define NMEA_MODE_M_STR "M"
#define NMEA_MODE_A      1
#define NMEA_MODE_M      2

typedef struct _NMEA_GSA_DATA
{
  /* Field 0  "A" = Auto selection "M" = Force  2D/3D fix (M = manual) */
  int Mode;               
  int FixMode;         /* Field 1  1 = No Fix 2 = 2D Fix 3 = 3D Fix */
  int PRNs[12];
  float PDOP;
  float HDOP;
  float VDOP;
} NMEA_GSA_DATA, *pNMEA_GSA_DATA;

#define NMEA_ACTIVE_STR "A"
#define NMEA_VOID_STR   "V"
#define NMEA_ACTIVE      1
#define NMEA_VOID        2

typedef struct _NMEA_RMC_DATA
{
  double TimeOfFixUTC;
  int Status;
  double Lat;
  int NorthSouth;
  double Long;
  int EastWest;
  double GroundSpeedKnots;
  double TrueHeading;
  unsigned long DateOfFix;
  int MagVar;
  int MagEastWest;
} NMEA_RMC_DATA, *pNMEA_RMC_DATA;

typedef struct _NMEA_ZDA_DATA
{
  double HrMinSecUTC;
  int Day;
  int Month;
  int Year;
  int LocalTimeZoneHr;
  int LocalTimeZoneMin;
} NMEA_ZDA_DATA, *pNMEA_ZDA_DATA;


void SendNMEA (void);

NMEA_STATUS NMEASendGPGGA (void);

NMEA_STATUS NMEAGetGPGGAData (pNMEA_GGA_DATA pNmeaData);

NMEA_STATUS NMEASendGPGSV (void);

NMEA_STATUS NMEAGetGPGSVData (pNMEA_GSV_DATA pNmeaGSVData);

NMEA_STATUS NMEASendGPGSA (void);

NMEA_STATUS NMEAGetGPGSAData (pNMEA_GSA_DATA pNmeaGSAData);

NMEA_STATUS NMEASendGPVTG (void);

NMEA_STATUS NMEAGetGPVTGData (pNMEA_VTG_DATA pNmeaVTGData);

NMEA_STATUS NMEASendGPRMC (void);

NMEA_STATUS NMEAGetGPRMCData (pNMEA_RMC_DATA pNmeaRMCData);

NMEA_STATUS NMEASendGPZDA (void);

NMEA_STATUS NMEAGetGPRZDAata (pNMEA_ZDA_DATA pNmeaZDAData);



void ftoa (float value, char *strFloat);
void ftod (double value, char *strDouble);
void ftod4 (double value, char *strDouble);
void ftodPrecision1 (double value, char *strDouble);


#endif /* NMEA_H */