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/* gpsd.h -- fundamental types and structures for the GPS daemon */
#include "config.h"
#include "gps.h"
#include <setjmp.h>
/* Some internal capabilities depend on which drivers we're compiling. */
#define ZODIAC_ENABLE EARTHMATE_ENABLE
#define BINARY_ENABLE (ZODIAC_ENABLE || SIRF_ENABLE || GARMIN_ENABLE)
#define NON_NMEA_ENABLE (TRIPMATE_ENABLE || BINARY_ENABLE)
#define NMEA_MAX 82 /* max length of NMEA sentence */
#define NMEA_BIG_BUF (2*NMEA_MAX+1) /* longer than longest NMEA sentence */
/*
* User Equivalent Range Error
* UERE is the square root of the sum of the squares of individual
* errors. We compute based on the following error budget for
* satellite range measurements. Note: this is only used if the
* GPS doesn't report estimated position error itself.
*
* From R.B Langley's 1997 "The GPS error budget".
* GPS World , Vol. 8, No. 3, pp. 51-56
*
* Atmospheric error -- ionosphere 7.0m
* Atmospheric error -- troposphere 0.7m
* Clock and ephemeris error 3.6m
* Receiver noise 1.5m
* Multipath effect 1.2m
*
* From Hoffmann-Wellenhof et al. (1997), "GPS: Theory and Practice", 4th
* Ed., Springer.
*
* Code range noise (C/A) 0.3m
* Code range noise (P-code) 0.03m
* Phase range 0.005m
*
* Taking the square root of the sum of aa squares...
* UERE=sqrt(7.0^2 + 0.7^2 + 3.6^2 + 1.5^2 + 1.2^2 + 0.3^2 + 0.03^2 + 0.005^2)
*
* See http://www.seismo.berkeley.edu/~battag/GAMITwrkshp/lecturenotes/unit1/
* for discussion.
*
* DGPS corrects for atmospheric distortion, ephemeris error, and satellite/
* receiver clock error. Thus:
* UERE = sqrt(1.5^2 + 1.2^2 + 0.3^2 + 0.03^2 + 0.005^2)
*/
#define UERE_NO_DGPS 8.1382
#define UERE_WITH_DGPS 1.9444
#define UERE(session) ((session->dsock==-1) ? UERE_NO_DGPS : UERE_WITH_DGPS)
struct gps_session_t;
struct gps_type_t {
/* GPS method table, describes how to talk to a particular GPS type */
char *typename, *trigger;
int (*probe)(struct gps_session_t *session);
void (*initializer)(struct gps_session_t *session);
void (*handle_input)(struct gps_session_t *session);
int (*rtcm_writer)(struct gps_session_t *session, char *rtcmbuf, int rtcmbytes);
int (*speed_switcher)(struct gps_session_t *session, int speed);
void (*wrapup)(struct gps_session_t *session);
int cycle;
};
#if defined (HAVE_SYS_TERMIOS_H)
#include <sys/termios.h>
#else
#if defined (HAVE_TERMIOS_H)
#include <termios.h>
#endif
#endif
/*
* The packet buffers need to be as long than the longest packet we
* expect to see in any protocol, because we have to be able to hold
* an entire packet for checksumming. Thus, in particular, they need
* to be as long as a SiRF MID 4 packet, 188 bytes payload plus eight bytes
* of header/length/checksum/trailer. But making this longer also
* slows down the autobauding.
*/
#define MAX_PACKET_LENGTH 193 /* 188 + 8 + 1 */
struct gps_session_t {
/* session object, encapsulates all global state */
struct gps_data_t gNMEAdata;
struct gps_type_t *device_type;
char *gpsd_device; /* where to find the GPS */
int dsock; /* socket to DGPS server */
int sentdgps; /* have we sent a DGPS correction? */
int fixcnt; /* count of good fixes seen */
struct termios ttyset, ttyset_old;
/* packet-getter internals */
int packet_type;
#define BAD_PACKET -1
#define NMEA_PACKET 0
#define SIRF_PACKET 1
#define ZODIAC_PACKET 2
unsigned char inbuffer[MAX_PACKET_LENGTH+1];
unsigned short inbuflen;
unsigned char *inbufptr;
unsigned char outbuffer[MAX_PACKET_LENGTH+1];
unsigned short outbuflen;
jmp_buf packet_error;
double poll_times[__FD_SETSIZE]; /* last daemon poll time */
#ifdef BINARY_ENABLE
#ifdef GARMIN_ENABLE /* private housekeeping stuff for the Garmin driver */
unsigned char GarminBuffer[4096 + 12]; /* Garmin packet buffer */
long GarminBufferLen; /* current GarminBuffer Length */
#endif /* GARMIN_ENABLE */
double separation; /* Geoidal separation */
#define NO_SEPARATION -99999 /* must be out of band */
int year, month, day;
int hours, minutes;
double seconds;
unsigned int driverstate; /* for private use */
#define SIRF_LT_231 0x01 /* SiRF at firmware rev < 231 */
#ifdef ZODIAC_ENABLE /* private housekeeping stuff for the Zodiac driver */
unsigned short sn; /* packet sequence number */
double mag_var; /* Magnetic variation in degrees */
/*
* Zodiac chipset channel status from PRWIZCH. Keep it so raw-mode
* translation of Zodiac binary protocol can send it up to the client.
*/
int Zs[MAXCHANNELS]; /* satellite PRNs */
int Zv[MAXCHANNELS]; /* signal values (0-7) */
#endif /* ZODIAC_ENABLE */
#endif /* BINARY_ENABLE */
};
#define PREFIX(pref, sentence) !strncmp(pref, sentence, sizeof(pref)-1)
#define TIME2DOUBLE(tv) (tv.tv_sec + tv.tv_usec/1e6)
/* here are the available GPS drivers */
extern struct gps_type_t **gpsd_drivers;
/* GPS library internal prototypes */
extern int nmea_parse(char *, struct gps_data_t *);
extern int nmea_send(int, const char *, ... );
extern int nmea_sane_satellites(struct gps_data_t *);
extern void nmea_add_checksum(char *);
extern int packet_sniff(struct gps_session_t *);
extern int packet_get_nmea(struct gps_session_t *);
extern int packet_get_sirf(struct gps_session_t *);
extern void packet_accept(struct gps_session_t *);
extern int gpsd_open(struct gps_session_t *);
extern int gpsd_switch_driver(struct gps_session_t *, char *);
extern int gpsd_set_speed(struct gps_session_t *, unsigned int, unsigned int);
extern int gpsd_get_speed(struct termios *);
extern void gpsd_close(struct gps_session_t *);
extern void gpsd_zero_satellites(struct gps_data_t *);
extern void gpsd_binary_fix_dump(struct gps_session_t *, char *);
extern void gpsd_binary_satellite_dump(struct gps_session_t *, char *);
extern void gpsd_binary_quality_dump(struct gps_session_t *, char *);
extern int netlib_connectsock(const char *, const char *, const char *);
/* External interface */
extern struct gps_session_t * gpsd_init(char *);
extern int gpsd_activate(struct gps_session_t *);
extern void gpsd_deactivate(struct gps_session_t *);
extern int gpsd_poll(struct gps_session_t *);
extern void gpsd_wrap(struct gps_session_t *);
/* caller should supply this */
void gpsd_report(int, const char *, ...);
#define DEFAULT_DEVICE_NAME "/dev/gps"
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