summaryrefslogtreecommitdiff
path: root/pseudonmea.c
blob: 84a22050056f2470ed9eff8227dba3b6e1a880b9 (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
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
/*
 * This file is Copyright (c) 2010 by the GPSD project
 * SPDX-License-Identifier: BSD-2-clause
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>

#include "gpsd.h"
#include "strfuncs.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;
}

void gpsd_position_fix_dump(struct gps_device_t *session,
			    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 > MODE_NO_FIX) {
	(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 (0 == isfinite(session->gpsdata.dop.hdop))
	    (void)strlcat(bufp, ",", len);
	else
	    str_appendf(bufp, len, "%.2f,", session->gpsdata.dop.hdop);
	if (0 == isfinite(session->gpsdata.fix.altitude))
	    (void)strlcat(bufp, ",", len);
	else
	    str_appendf(bufp, len, "%.2f,M,", session->gpsdata.fix.altitude);
	if (0 == isfinite(session->gpsdata.separation))
	    (void)strlcat(bufp, ",", len);
	else
	    str_appendf(bufp, len, "%.3f,M,", session->gpsdata.separation);
	if (0 == isfinite(session->mag_var))
	    (void)strlcat(bufp, ",", len);
	else {
	    str_appendf(bufp, len, "%3.2f,", fabs(session->mag_var));
	    (void)strlcat(bufp, (session->mag_var > 0) ? "E" : "W", len);
	}
	nmea_add_checksum(bufp);
    }
}


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 (0 != isfinite(session->gpsdata.fix.time)) {
	intfixtime = (time_t) session->gpsdata.fix.time;
	(void)gmtime_r(&intfixtime, &tm);
	tm.tm_mon++;
	tm.tm_year %= 100;
    }
#define ZEROIZE(x)	(isfinite(x)==0 ? 0.0 : x)
    (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);
#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) {
	    bufp2 = bufp + strlen(bufp);
	    str_appendf(bufp, len,
			    "$GPGSV,%d,%d,%02d",
			    ((session->gpsdata.satellites_visible - 1) / 4) +
			    1, (i / 4) + 1,
			    session->gpsdata.satellites_visible);
	}
	if (i < session->gpsdata.satellites_visible) {
            if ( 0 == session->gpsdata.skyview[i].PRN) {
                /* bad prn, just make all zeros */
                str_appendf(bufp, len, ",00,00,000,00");
            } else {
                str_appendf(bufp, len,
			    ",%02d,%02d,%03d,%02.0f",
			    session->gpsdata.skyview[i].PRN,
			    session->gpsdata.skyview[i].elevation,
			    session->gpsdata.skyview[i].azimuth,
			    session->gpsdata.skyview[i].ss);
            }
        }
	if (i % 4 == 3 || i == session->gpsdata.satellites_visible - 1) {
	    nmea_add_checksum(bufp2);
	}
    }

#ifdef ZODIAC_ENABLE
    if (session->lexer.type == ZODIAC_PACKET
	&& session->driver.zodiac.Zs[0] != 0) {
	bufp2 = bufp + strlen(bufp);
	str_appendf(bufp, len, "$PRWIZCH");
	for (i = 0; i < ZODIAC_CHANNELS; i++) {
	    str_appendf(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)
{
    char *bufp2;
    bufp[0] = '\0';

    if (session->device_type != NULL) {
	int i, j;
	int max_channels = session->device_type->channels;

	/* GPGSA commonly has exactly 12 channels, enforce that as a MAX */
	if ( 12 < max_channels ) {
	    /* what to do with the excess channels? */
	    max_channels = 12;
	}

	bufp2 = bufp + strlen(bufp);
	(void)snprintf(bufp, len,
		       "$GPGSA,%c,%d,", 'A', session->gpsdata.fix.mode);
	j = 0;
	for (i = 0; i < max_channels; i++) {
	    if (session->gpsdata.skyview[i].used == true){
		str_appendf(bufp, len, "%d,", session->gpsdata.skyview[i].PRN);
	        j++;
	    }
	}
	for (i = j; i < max_channels; i++) {
	    /* fill out the empty slots */
	    (void)strlcat(bufp, ",", len);
	}
	if (session->gpsdata.fix.mode == MODE_NO_FIX)
	    (void)strlcat(bufp, ",,,", len);
	else {
            /* output the DOPs, NaN as blanks */
	    if ( 0 != isfinite( session->gpsdata.dop.pdop ) ) {
		str_appendf(bufp, len, "%.1f,", session->gpsdata.dop.pdop);
	    } else {
		(void)strlcat(bufp, ",", len);
	    }
	    if ( 0 != isfinite( session->gpsdata.dop.hdop ) ) {
		str_appendf(bufp, len, "%.1f,", session->gpsdata.dop.hdop);
	    } else {
		(void)strlcat(bufp, ",", len);
	    }
	    if ( 0 != isfinite( session->gpsdata.dop.vdop ) ) {
		str_appendf(bufp, len, "%.1f*", session->gpsdata.dop.vdop);
	    } else {
		(void)strlcat(bufp, "*", len);
	    }
	}
	nmea_add_checksum(bufp2);
    }
    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 (0 != isfinite(session->gpsdata.fix.time)) {
	    intfixtime = (time_t) session->gpsdata.fix.time;
	    (void)gmtime_r(&intfixtime, &tm);
	}
	bufp2 = bufp + strlen(bufp);
#define ZEROIZE(x)      (isfinite(x)==0 ? 0.0 : x)
	str_appendf(bufp, len,
		       "$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(bufp2);
    }
#undef ZEROIZE
}

static void gpsd_binary_time_dump(struct gps_device_t *session,
				     char bufp[], size_t len)
{
    struct tm tm;
    double integral;
    time_t integral_time;

    if (session->newdata.mode > MODE_NO_FIX) {
	double fractional = modf(session->newdata.time, &integral);
	integral_time = (time_t) integral;
	(void)gmtime_r(&integral_time, &tm);
	/*
	 * We pin this report to the GMT/UTC timezone.  This may be technically
	 * incorrect; our sources on ZDA suggest that it should report local
	 * timezone. But no GPS we've ever seen actually does this, because it
	 * would require embedding a location-to-TZ database in the receiver.
	 * And even if we could do that, it would make our regression tests
	 * break any time they were run in a timezone different from the one
	 * where they were generated.
	 */
	(void)snprintf(bufp, len,
		       "$GPZDA,%02d%02d%05.2f,%02d,%02d,%04d,00,00",
		       tm.tm_hour,
		       tm.tm_min,
		       (double)tm.tm_sec + fractional,
		       tm.tm_mday,
		       tm.tm_mon + 1,
		       tm.tm_year + 1900);
	nmea_add_checksum(bufp);
    }
}

static void gpsd_binary_almanac_dump(struct gps_device_t *session,
				     char bufp[], size_t len)
{
    if ( session->gpsdata.subframe.is_almanac ) {
	(void)snprintf(bufp, len,
			"$GPALM,1,1,%02d,%04d,%02x,%04x,%02x,%04x,%04x,%05x,%06x,%06x,%06x,%03x,%03x",
		       (int)session->gpsdata.subframe.sub5.almanac.sv,
		       (int)session->context->gps_week % 1024,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.svh,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.e,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.toa,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.deltai,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.Omegad,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.sqrtA,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.omega,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.Omega0,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.M0,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.af0,
		       (unsigned int)session->gpsdata.subframe.sub5.almanac.af1);
	nmea_add_checksum(bufp);
    }
}

#ifdef AIVDM_ENABLE

#define GETLEFT(a) (((a%6) == 0) ? 0 : (6 - (a%6)))

static void gpsd_binary_ais_dump(struct gps_device_t *session,
				     char bufp[], size_t len)
{
    char type[8] = "!AIVDM";
    unsigned char data[256];
    unsigned int msg1, msg2;
    char numc[4];
    char channel;
    unsigned int left;
    unsigned int datalen;
    unsigned int offset;

    channel = 'A';
    if (session->driver.aivdm.ais_channel == 'B') {
        channel = 'B';
    }

    memset(data, 0, sizeof(data));
    datalen = ais_binary_encode(&session->gpsdata.ais, &data[0], 0);
    if (datalen > 6*60) {
	static int number1 = 0;
        msg1 = datalen / (6*60);
	if ((datalen % (6*60)) != 0) {
	    msg1 += 1;
	}
	numc[0] = '0' + (char)(number1 & 0x0f);
	numc[1] = '\0';
	number1 += 1;
	if (number1 > 9) {
	    number1 = 0;
	}
	offset = 0;
	for (msg2=1;msg2<=msg1;msg2++) {
	    unsigned char old;

	    old = '\0';
	    if (strlen((char *)&data[(msg2-1)*60]) > 60) {
	        old = data[(msg2-0)*60];
	        data[(msg2-0)*60] = '\0';
	    }
	    if (datalen >= (6*60)) {
	        left = 0;
		datalen -= 6*60;
	    } else {
	        left = GETLEFT(datalen);
	    }
	    (void)snprintf(&bufp[offset], len-offset,
			   "%s,%u,%u,%s,%c,%s,%u",
			   type,
			   msg1,
			   msg2,
			   numc,
			   channel,
			   (char *)&data[(msg2-1)*60],
			   left);

	    nmea_add_checksum(&bufp[offset]);
	    if (old != (unsigned char)'\0') {
		data[(msg2-0)*60] = old;
	    }
	    offset = (unsigned int) strlen(bufp);
	}
    } else if (datalen > 0) {
        msg1 = 1;
	msg2 = 1;
	numc[0] = '\0';
        left = GETLEFT(datalen);
	(void)snprintf(bufp, len,
		       "%s,%u,%u,%s,%c,%s,%u",
		       type,
		       msg1,
		       msg2,
		       numc,
		       channel,
		       (char *)data,
		       left);

	nmea_add_checksum(bufp);
    }

    if (session->gpsdata.ais.type == 24) {
        msg1 = 1;
	msg2 = 1;
	numc[0] = '\0';

        memset(data, 0, sizeof(data));
	datalen = ais_binary_encode(&session->gpsdata.ais, &data[0], 1);
	if (datalen > 0) {
	    left = GETLEFT(datalen);
	    offset = (unsigned int)strlen(bufp);
	    (void)snprintf(&bufp[offset], len-offset,
		           "%s,%u,%u,%s,%c,%s,%u",
		           type,
		           msg1,
		           msg2,
		           numc,
		           channel,
		           (char *)data,
		           left);
	nmea_add_checksum(bufp+offset);
	}
    }
}
#endif /* AIVDM_ENABLE */

/* *INDENT-OFF* */
void nmea_tpv_dump(struct gps_device_t *session,
		   char bufp[], size_t len)
{
    bufp[0] = '\0';
    if ((session->gpsdata.set & TIME_SET) != 0)
	gpsd_binary_time_dump(session, bufp + strlen(bufp),
			      len - strlen(bufp));
    if ((session->gpsdata.set & LATLON_SET) != 0) {
	gpsd_position_fix_dump(session, bufp + strlen(bufp),
			       len - strlen(bufp));
	gpsd_transit_fix_dump(session, bufp + strlen(bufp),
			      len - strlen(bufp));
    }
    if ((session->gpsdata.set
	 & (MODE_SET | DOP_SET | USED_IS | HERR_SET | VERR_SET)) != 0)
	gpsd_binary_quality_dump(session, bufp + strlen(bufp),
				 len - strlen(bufp));
}
/* *INDENT-ON* */

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

void nmea_subframe_dump(struct gps_device_t *session,
		   char bufp[], size_t len)
{
    bufp[0] = '\0';
    if ((session->gpsdata.set & SUBFRAME_SET) != 0)
	gpsd_binary_almanac_dump(session, bufp + strlen(bufp),
				   len - strlen(bufp));
}

#ifdef AIVDM_ENABLE
void nmea_ais_dump(struct gps_device_t *session,
		   char bufp[], size_t len)
{
    bufp[0] = '\0';
    if ((session->gpsdata.set & AIS_SET) != 0)
	gpsd_binary_ais_dump(session, bufp + strlen(bufp),
				   len - strlen(bufp));
}
#endif /* AIVDM_ENABLE */


/* pseudonmea.c ends here */