1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/* gpsd.h -- fundamental types and structures for the GPS daemon */
#include "config.h"
#include "gps.h"
#include "gpsutils.h"
/* Some internal capabilities depend on which drivers we're compiling. */
#ifdef EARTHMATE_ENABLE
#define ZODIAC_ENABLE
#endif
#if defined(ZODIAC_ENABLE) || defined(SIRF_ENABLE) || defined(GARMIN_ENABLE)
#define BINARY_ENABLE
#endif
#if defined(TRIPMATE_ENABLE) || defined(BINARY_ENABLE)
#define NON_NMEA_ENABLE
#endif
#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)
*
* Note: we're assume these are 1-sigma error ranges. This needs to
* be checked in the sources.
*
* 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_device_t;
struct gps_type_t {
/* GPS method table, describes how to talk to a particular GPS type */
char *typename, *trigger;
int (*probe)(struct gps_device_t *session);
void (*initializer)(struct gps_device_t *session);
int (*get_packet)(struct gps_device_t *session, int waiting);
int (*parse_packet)(struct gps_device_t *session);
int (*rtcm_writer)(struct gps_device_t *session, char *rtcmbuf, int rtcmbytes);
int (*speed_switcher)(struct gps_device_t *session, int speed);
void (*mode_switcher)(struct gps_device_t *session, int mode);
void (*wrapup)(struct gps_device_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.
*/
#define MAX_PACKET_LENGTH 196 /* 188 + 8 */
struct gps_device_t {
/* session object, encapsulates all global state */
struct gps_data_t gpsdata;
struct gps_type_t *device_type;
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_full; /* do we presently see a full packet? */
int packet_type;
#define BAD_PACKET -1
#define NMEA_PACKET 0
#define SIRF_PACKET 1
#define ZODIAC_PACKET 2
unsigned int packet_state;
unsigned int packet_length;
unsigned char inbuffer[MAX_PACKET_LENGTH*2+1];
unsigned short inbuflen;
unsigned char *inbufptr;
unsigned char outbuffer[MAX_PACKET_LENGTH+1];
unsigned short outbuflen;
unsigned long counter;
#ifdef BINARY_ENABLE
struct gps_fix_t lastfix; /* use to compute uncertainties */
unsigned int driverstate; /* for private use */
double separation; /* Geoidal separation, MSL - WGS84 (Meters) */
#define NO_SEPARATION -99999 /* must be out of band */
double mag_var; /* Magnetic variation in degrees */
#ifdef GARMIN_ENABLE /* private housekeeping stuff for the Garmin driver */
void *GarminBuffer; /* Pointer Garmin packet buffer
void *, to keep the packet details out of the
gloabl contect and save spave */
long GarminBufferLen; /* current GarminBuffer Length */
#endif /* GARMIN_ENABLE */
#ifdef ZODIAC_ENABLE /* private housekeeping stuff for the Zodiac driver */
unsigned short sn; /* packet sequence number */
/*
* 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 */
#ifdef NTPSHM_ENABLE
struct shmTime *shmTime;
unsigned int time_seen;
#define TIME_SEEN_GPS_1 0x01 /* Seen GPS time variant 1? */
#define TIME_SEEN_GPS_2 0x02 /* Seen GPS time variant 1? */
#define TIME_SEEN_UTC_1 0x04 /* Seen UTC time variant 1? */
#define TIME_SEEN_UTC_2 0x08 /* Seen UTC time variant 1? */
#define TIME_SEEN_PPS 0x10 /* Seen PPS signal? */
#endif /* NTPSHM_ENABLE */
double poll_times[FD_SETSIZE]; /* last daemon poll time */
};
#define IS_HIGHEST_BIT(v,m) !(v & ~((m<<1)-1))
/* 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 void nmea_add_checksum(char *);
extern int sirf_parse(struct gps_device_t *, unsigned char *, int);
extern int packet_get(struct gps_device_t *, int);
extern int packet_sniff(struct gps_device_t *);
extern int gpsd_open(struct gps_device_t *);
extern int gpsd_switch_driver(struct gps_device_t *, char *);
extern int gpsd_set_speed(struct gps_device_t *, unsigned int, unsigned int);
extern int gpsd_get_speed(struct termios *);
extern void gpsd_close(struct gps_device_t *);
extern void gpsd_raw_hook(struct gps_device_t *, char *);
extern void gpsd_zero_satellites(struct gps_data_t *);
extern void gpsd_binary_fix_dump(struct gps_device_t *, char *);
extern void gpsd_binary_satellite_dump(struct gps_device_t *, char *);
extern void gpsd_binary_quality_dump(struct gps_device_t *, char *);
extern int netlib_connectsock(const char *, const char *, const char *);
extern int ntpshm_init(struct gps_device_t *);
extern int ntpshm_put(struct gps_device_t *, double);
extern void ecef_to_wgs84fix(struct gps_fix_t *,
double, double, double,
double, double, double);
/* External interface */
extern int gpsd_open_dgps(char *);
extern struct gps_device_t * gpsd_init(char *device);
extern int gpsd_activate(struct gps_device_t *);
extern void gpsd_deactivate(struct gps_device_t *);
extern int gpsd_poll(struct gps_device_t *);
extern void gpsd_wrap(struct gps_device_t *);
/* caller should supply this */
void gpsd_report(int, const char *, ...);
|
