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/* gps.h -- interface of the libgps library */
#ifndef gps_h
# define gps_h 1
#ifdef __cplusplus
extern "C" {
#endif
#include <sys/types.h>
#include <sys/time.h>
#include <time.h>
#include "gpsutils.h"
#define MAXCHANNELS 12 /* maximum GPS channels (*not* satellites!) */
#define MAXTAGLEN 6 /* maximum length of sentence tag name */
/*
* The structure describing an uncertainty volume in kinematic space.
* This is what GPSes are meant to produce; all the other info is
* technical impedimenta.
*
* Values of 0 for ep[thvdsc] mean the corresponding error estimate
* is not available.
*
* Usually all the information in this structure was considered valid
* by the GPS at the time of update. This will be so if you are using
* a GPS chipset that speaks SiRF binary, Garmin binary, or Zodiac binary.
* This covers over 80% of GPS products in early 2005.
*
* If you are using a chipset that speaks NMEA, this structure is updated
* in bits by GPRMC (lat/lon, track, speed), GPGGA (alt, climb), GPGLL
* (lat/lon), and GPGSA (eph, epv). Most NMEA GPSes take a single fix
* at the beginning of a 1-second cycle and report the same timestamp in
* GPRMC, GPGGA, and GPGLL; for these, all info is guaranteed correctly
* synced to the time member, but you'll get different stages of the same
* update depending on where in the cycle you poll. A very few GPSes,
* like the Garmin 48, take a new fix before more than one of of
* GPRMC/GPGGA/GPGLL during a single cycle; thus, they may have different
* timestamps and some data in this structure can be up to 1 cycle (usually
* 1 second) older than the fix time.
*
* Time uncertainty is expected value (mean).
* Position and velocity uncertainties are 1-sigma values with a mean of zero.
*/
struct gps_fix_t {
double time; /* Time of update, seconds since Unix epoch */
int mode; /* Mode of fix */
#define MODE_NOT_SEEN 0 /* mode update not seen yet */
#define MODE_NO_FIX 1 /* none */
#define MODE_2D 2 /* good for latitude/longitude */
#define MODE_3D 3 /* good for altitude/climb too */
double ept; /* Expected time uncertainty */
double latitude; /* Latitude in degrees (valid if mode >= 2) */
double longitude; /* Longitude in degrees (valid if mode >= 2) */
double eph; /* Horizontal position uncertainty, meters */
double altitude; /* Altitude in meters (valid if mode == 3) */
#define ALTITUDE_NOT_VALID -999
double epv; /* Vertical position uncertainty, meters */
double track; /* Course made good (relative to true north) */
#define TRACK_NOT_VALID -1 /* No course/speed data yet */
double epd; /* Track uncertainty, degrees */
double speed; /* Speed over ground */
double eps; /* Speed uncertainty, meters/sec */
double climb; /* Vertical speed, meters/sec */
double epc; /* Vertical speed uncertainty */
};
struct gps_data_t {
unsigned long valid; /* validity mask */
#define ONLINE_SET 0x000001
#define TIME_SET 0x000002
#define TIMERR_SET 0x000004
#define LATLON_SET 0x000008
#define ALTITUDE_SET 0x000010
#define SPEED_SET 0x000020
#define TRACK_SET 0x000040
#define CLIMB_SET 0x000080
#define STATUS_SET 0x000100
#define MODE_SET 0x000200
#define HDOP_SET 0x000400
#define VDOP_SET 0x000800
#define PDOP_SET 0x001000
#define HERR_SET 0x002000
#define VERR_SET 0x004000
#define PERR_SET 0x008000
#define SATELLITE_SET 0x010000
#define SPEEDERR_SET 0x020000
#define TRACKERR_SET 0x040000
#define CLIMBERR_SET 0x080000
#define ERROR_SET 0x100000
double online; /* NZ if GPS is on line, 0 if not.
*
* Note: gpsd clears this flag when sentences
* fail to show up within the GPS's normal
* send cycle time. If the host-to-GPS
* link is lossy enough to drop entire
* sentences, this flag will be
* prone to false negatives.
*/
struct gps_fix_t fix; /* PVT data */
/* GPS status -- always valid */
int status; /* Do we have a fix? */
#define STATUS_NO_FIX 0 /* no */
#define STATUS_FIX 1 /* yes, without DGPS */
#define STATUS_DGPS_FIX 2 /* yes, with DGPS */
/* precision of fix -- valid if satellites_used > 0 */
int satellites_used; /* Number of satellites used in solution */
int used[MAXCHANNELS]; /* Used in last fix? */
double pdop, hdop, vdop; /* Dilution of precision */
/* redundant with the estimate elments in the fix structure */
double epe; /* estimated spherical position error, 1 sigma (meters) */
/* satellite status -- valid when satellites > 0 */
int satellites; /* # of satellites in view */
int PRN[MAXCHANNELS]; /* PRNs of satellite */
int elevation[MAXCHANNELS]; /* elevation of satellite */
int azimuth[MAXCHANNELS]; /* azimuth */
int ss[MAXCHANNELS]; /* signal strength */
int part, await; /* for tracking GSV parts */
/* what type gpsd thinks the device is */
char *gps_id; /* only valid if non-null. */
unsigned int baudrate, stopbits; /* RS232 link paramters */
unsigned int driver_mode; /* whether driver is in native mode or not */
/* profiling data for last sentence */
int profiling; /* profiling enabled? */
char tag[MAXTAGLEN+1]; /* tag of last sentence processed */
int sentence_length; /* character count of last sentence */
double sentence_time; /* sentence timestamp */
double d_xmit_time; /* beginning of sentence transmission */
double d_recv_time; /* daemon receipt time (-> E1+T1) */
double d_decode_time; /* daemon end-of-decode time (-> D1) */
double poll_time; /* daemon poll time (-> W) */
double emit_time; /* emission time (-> E2) */
double c_recv_time; /* client receipt time (-> T2) */
double c_decode_time; /* client end-of-decode time (-> D2) */
unsigned int cycle; /* refresh cycle time in seconds */
/* these members are private */
int gps_fd; /* socket or file descriptor to GPS */
void (*raw_hook)(struct gps_data_t *, char *);/* Raw-mode hook for GPS data. */
int seen_sentences; /* track which sentences have been seen */
#define GPRMC 0x01
#define GPGGA 0x02
#define GPGLL 0x04
#define GPVTG 0x08
#define GPGSA 0x10
#define GPGSV 0x20
#define GPZDA 0x40
#define PGRME 0x80
struct tm nmea_date;
double subseconds;
};
struct gps_data_t *gps_open(const char *host, const char *port);
int gps_close(struct gps_data_t *);
int gps_query(struct gps_data_t *gpsdata, const char *requests);
int gps_poll(struct gps_data_t *gpsdata);
void gps_set_raw_hook(struct gps_data_t *gpsdata, void (*hook)(struct gps_data_t *sentence, char *buf));
/* some multipliers for interpreting GPS output */
#define METERS_TO_FEET 3.2808399 /* Meters to U.S./British feet */
#define METERS_TO_MILES 0.00062137119 /* Meters to miles */
#define KNOTS_TO_MPH 1.1507794 /* Knots to miles per hour */
#define KNOTS_TO_KPH 1.852 /* Knots to kilometers per hour */
#define MPS_TO_KNOTS 1.9437 /* Meters per second to knots */
/* miles and knots are both the international standard versions of the units */
/* angle conversion multipliers */
#define PI 3.1415926535897932384626433832795029L
#define RAD_2_DEG 57.2957795130823208767981548141051703L
#define DEG_2_RAD 0.0174532925199432957692369076848861271L
/* gps_open() errno return values */
#define NL_NOSERVICE -1 /* can't get service entry */
#define NL_NOHOST -2 /* can't get host entry */
#define NL_NOPROTO -3 /* can't get protocol entry */
#define NL_NOSOCK -4 /* can't create socket */
#define NL_NOSOCKOPT -5 /* error SETSOCKOPT SO_REUSEADDR */
#define NL_NOCONNECT -6 /* can't connect to host */
#define DEFAULT_GPSD_PORT "2947" /* IANA assignment */
#ifdef __cplusplus
} /* End of the 'extern "C"' block */
#endif
#endif /* gps_h */
/* gps.h ends here */
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