summaryrefslogtreecommitdiff
path: root/pseudonmea.c
blob: 99979b1084995def97508cedee823c3e81b68aef (plain)
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
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/*
 * This file is Copyright (c) 2010 by the GPSD project
 * BSD terms apply: see the file COPYING in the distribution root for details.
 */
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <time.h>

#include "gpsd.h"

/*
 * Support for generic binary drivers.  These functions dump NMEA for passing
 * to the client in raw mode.  They assume that (a) the public gps.h structure 
 * members are in a valid state, (b) that the private members hours, minutes, 
 * and seconds have also been filled in, (c) that if the private member
 * mag_var is not NAN it is a magnetic variation in degrees that should be
 * passed on, and (d) if the private member separation does not have the
 * value NAN, it is a valid WGS84 geoidal separation in meters for the fix.
 */

static double degtodm(double angle)
/* decimal degrees to GPS-style, degrees first followed by minutes */
{
    double fraction, integer;
    fraction = modf(angle, &integer);
    return floor(angle) * 100 + fraction * 60;
}

/*@ -mustdefine @*/
void gpsd_position_fix_dump(struct gps_device_t *session,
			    /*@out@*/ char bufp[], size_t len)
{
    struct tm tm;
    time_t intfixtime;

    intfixtime = (time_t) session->gpsdata.fix.time;
    (void)gmtime_r(&intfixtime, &tm);
    if (session->gpsdata.fix.mode > 1) {
	(void)snprintf(bufp, len,
		       "$GPGGA,%02d%02d%02d,%09.4f,%c,%010.4f,%c,%d,%02d,",
		       tm.tm_hour,
		       tm.tm_min,
		       tm.tm_sec,
		       degtodm(fabs(session->gpsdata.fix.latitude)),
		       ((session->gpsdata.fix.latitude > 0) ? 'N' : 'S'),
		       degtodm(fabs(session->gpsdata.fix.longitude)),
		       ((session->gpsdata.fix.longitude > 0) ? 'E' : 'W'),
		       session->gpsdata.status,
		       session->gpsdata.satellites_used);
	if (isnan(session->gpsdata.dop.hdop))
	    (void)strlcat(bufp, ",", len);
	else
	    (void)snprintf(bufp + strlen(bufp), len - strlen(bufp),
			   "%.2f,", session->gpsdata.dop.hdop);
	if (isnan(session->gpsdata.fix.altitude))
	    (void)strlcat(bufp, ",", len);
	else
	    (void)snprintf(bufp + strlen(bufp), len - strlen(bufp),
			   "%.2f,M,", session->gpsdata.fix.altitude);
	if (isnan(session->gpsdata.separation))
	    (void)strlcat(bufp, ",", len);
	else
	    (void)snprintf(bufp + strlen(bufp), len - strlen(bufp),
			   "%.3f,M,", session->gpsdata.separation);
	if (isnan(session->mag_var))
	    (void)strlcat(bufp, ",", len);
	else {
	    (void)snprintf(bufp + strlen(bufp),
			   len - strlen(bufp),
			   "%3.2f,", fabs(session->mag_var));
	    (void)strlcat(bufp, (session->mag_var > 0) ? "E" : "W", len);
	}
	nmea_add_checksum(bufp);
    }
}

/*@ +mustdefine @*/

static void gpsd_transit_fix_dump(struct gps_device_t *session,
				  char bufp[], size_t len)
{
    struct tm tm;
    time_t intfixtime;

    tm.tm_mday = tm.tm_mon = tm.tm_year = tm.tm_hour = tm.tm_min = tm.tm_sec =
	0;
    if (isnan(session->gpsdata.fix.time) == 0) {
	intfixtime = (time_t) session->gpsdata.fix.time;
	(void)gmtime_r(&intfixtime, &tm);
	tm.tm_mon++;
	tm.tm_year %= 100;
    }
#define ZEROIZE(x)	(isnan(x)!=0 ? 0.0 : x)
    /*@ -usedef @*/
    (void)snprintf(bufp, len,
		   "$GPRMC,%02d%02d%02d,%c,%09.4f,%c,%010.4f,%c,%.4f,%.3f,%02d%02d%02d,,",
		   tm.tm_hour,
		   tm.tm_min,
		   tm.tm_sec,
		   session->gpsdata.status ? 'A' : 'V',
		   ZEROIZE(degtodm(fabs(session->gpsdata.fix.latitude))),
		   ((session->gpsdata.fix.latitude > 0) ? 'N' : 'S'),
		   ZEROIZE(degtodm(fabs(session->gpsdata.fix.longitude))),
		   ((session->gpsdata.fix.longitude > 0) ? 'E' : 'W'),
		   ZEROIZE(session->gpsdata.fix.speed * MPS_TO_KNOTS),
		   ZEROIZE(session->gpsdata.fix.track),
		   tm.tm_mday, tm.tm_mon, tm.tm_year);
    /*@ +usedef @*/
#undef ZEROIZE
    nmea_add_checksum(bufp);
}

static void gpsd_binary_satellite_dump(struct gps_device_t *session,
				       char bufp[], size_t len)
{
    int i;
    char *bufp2 = bufp;
    bufp[0] = '\0';

    for (i = 0; i < session->gpsdata.satellites_visible; i++) {
	if (i % 4 == 0) {
	    bufp += strlen(bufp);
	    bufp2 = bufp;
	    len -= snprintf(bufp, len,
			    "$GPGSV,%d,%d,%02d",
			    ((session->gpsdata.satellites_visible - 1) / 4) +
			    1, (i / 4) + 1,
			    session->gpsdata.satellites_visible);
	}
	bufp += strlen(bufp);
	if (i < session->gpsdata.satellites_visible)
	    len -= snprintf(bufp, len,
			    ",%02d,%02d,%03d,%02.0f",
			    session->gpsdata.PRN[i],
			    session->gpsdata.elevation[i],
			    session->gpsdata.azimuth[i],
			    session->gpsdata.ss[i]);
	if (i % 4 == 3 || i == session->gpsdata.satellites_visible - 1) {
	    nmea_add_checksum(bufp2);
	    len -= 5;
	}
    }

#ifdef ZODIAC_ENABLE
    if (session->packet.type == ZODIAC_PACKET
	&& session->driver.zodiac.Zs[0] != 0) {
	bufp += strlen(bufp);
	bufp2 = bufp;
	(void)strlcpy(bufp, "$PRWIZCH", len);
	for (i = 0; i < ZODIAC_CHANNELS; i++) {
	    len -= snprintf(bufp + strlen(bufp), len,
			    ",%02u,%X",
			    session->driver.zodiac.Zs[i],
			    session->driver.zodiac.Zv[i] & 0x0f);
	}
	nmea_add_checksum(bufp2);
    }
#endif /* ZODIAC_ENABLE */
}

static void gpsd_binary_quality_dump(struct gps_device_t *session,
				     char bufp[], size_t len)
{
    int i, j;
    char *bufp2 = bufp;
    bool used_valid = (session->gpsdata.set & USED_IS) != 0;

    if (session->device_type != NULL && (session->gpsdata.set & MODE_IS) != 0) {
	(void)snprintf(bufp, len - strlen(bufp),
		       "$GPGSA,%c,%d,", 'A', session->gpsdata.fix.mode);
	j = 0;
	for (i = 0; i < session->device_type->channels; i++) {
	    if (session->gpsdata.used[i]) {
		bufp += strlen(bufp);
		(void)snprintf(bufp, len - strlen(bufp),
			       "%02d,",
			       used_valid ? session->gpsdata.used[i] : 0);
		j++;
	    }
	}
	for (i = j; i < session->device_type->channels; i++) {
	    bufp += strlen(bufp);
	    (void)strlcpy(bufp, ",", len);
	}
	bufp += strlen(bufp);
#define ZEROIZE(x)	(isnan(x)!=0 ? 0.0 : x)
	if (session->gpsdata.fix.mode == MODE_NO_FIX)
	    (void)strlcat(bufp, ",,,", len);
	else
	    (void)snprintf(bufp, len - strlen(bufp),
			   "%.1f,%.1f,%.1f*",
			   ZEROIZE(session->gpsdata.dop.pdop),
			   ZEROIZE(session->gpsdata.dop.hdop),
			   ZEROIZE(session->gpsdata.dop.vdop));
	nmea_add_checksum(bufp2);
	bufp += strlen(bufp);
    }
    if (isfinite(session->gpsdata.fix.epx)!=0
	&& isfinite(session->gpsdata.fix.epy)!=0
	&& isfinite(session->gpsdata.fix.epv)!=0
	&& isfinite(session->gpsdata.epe)!=0) {
	struct tm tm;
	time_t intfixtime;

	tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
	if (isnan(session->gpsdata.fix.time) == 0) {
	    intfixtime = (time_t) session->gpsdata.fix.time;
	    (void)gmtime_r(&intfixtime, &tm);
	}
	(void)snprintf(bufp, len - strlen(bufp),
		       "$GPGBS,%02d%02d%02d,%.2f,M,%.2f,M,%.2f,M",
		       tm.tm_hour, tm.tm_min, tm.tm_sec,
		       ZEROIZE(session->gpsdata.fix.epx),
		       ZEROIZE(session->gpsdata.fix.epy),
		       ZEROIZE(session->gpsdata.fix.epv));
	nmea_add_checksum(bufp);
    }
#undef ZEROIZE
}

/*@-compdef -mustdefine@*/
/* *INDENT-OFF* */
void nmea_tpv_dump(struct gps_device_t *session,
		   /*@out@*/ char bufp[], size_t len)
{
    bufp[0] = '\0';
    if ((session->gpsdata.set & LATLON_IS) != 0) {
	gpsd_position_fix_dump(session, bufp, len);
	gpsd_transit_fix_dump(session, bufp + strlen(bufp),
			      len - strlen(bufp));
    }
    if ((session->gpsdata.set
	 & (MODE_IS | DOP_IS | USED_IS | HERR_IS | VERR_IS)) != 0)
	gpsd_binary_quality_dump(session, bufp + strlen(bufp),
				 len - strlen(bufp));
}
/* *INDENT-ON* */

void nmea_sky_dump(struct gps_device_t *session,
		   /*@out@*/ char bufp[], size_t len)
{
    bufp[0] = '\0';
    if ((session->gpsdata.set & SATELLITE_IS) != 0)
	gpsd_binary_satellite_dump(session, bufp + strlen(bufp),
				   len - strlen(bufp));
}

/*@+compdef +mustdefine@*/

/* pseudonmea.c ends here */