summaryrefslogtreecommitdiff
path: root/driver_evermore.c
blob: 0566f567d65c9028f88a22e6f1027382046f9206 (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
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
/*
 *
 * This is the gpsd driver for EverMore GPSes.  They have both an NMEA and
 * a binary reporting mode, with the interesting property that they will
 * cheerfully accept binary commands (such as speed changes) while in NMEA
 * mode.
 *
 * Binary mode would give us atomic fix reports, but it has one large drawback:
 * the Navigation Data Out message doesn't report a leap-second offset, so it
 * is not actually possible to collect a leap-second offset from it. Therefore
 * we'll normally run the driver in NMEA mode.
 *
 * About the only thing binary mode gives that NMEA won't is TDOP and raw
 * pseudoranges, but gpsd does its own DOPs from skyview. By default we'll
 * trade away raw data to get accurate time.
 *
 * The vendor site is <http://www.emt.com.tw>.
 *
 * This driver was written by Petr Slansky based on a framework by Eric S.
 * Raymond.  The following remarks are by Petr Slansky.
 *
 * Snooping on the serial the communication between a Windows program and
 * an Evermore chipset reveals some messages not described in the vendor
 * documentation (Issue C of Aug 2002):
 *
 * 10 02 06 84 00 00 00 84 10 03	switch to binary mode (84 00 00 00)
 * 10 02 06 84 01 00 00 85 10 03	switch to NMEA mode (84 01 00 00)
 *
 * 10 02 06 89 01 00 00 8a 10 03        set baud rate 4800
 * 10 02 06 89 01 01 00 8b 10 03        set baud rate 9600
 * 10 02 06 89 01 02 00 8c 10 03        set baud rate 19200
 * 10 02 06 89 01 03 00 8d 10 03        set baud rate 38400
 *
 * 10 02 06 8D 00 01 00 8E 10 03        switch to datum ID 001 (WGS-84)
 * 10 02 06 8D 00 D8 00 65 10 03        switch to datum ID 217 (WGS-72)
 *
 * These don't entail a reset of GPS as the 0x80 message does.
 *
 * 10 02 04 38 85 bd 10 03     answer from GPS to 0x85 message; ACK message
 * 10 02 04 38 8d c5 10 03     answer from GPS to 0x8d message; ACK message
 * 10 02 04 38 8e c6 10 03     answer from GPS to 0x8e message; ACK message
 * 10 02 04 38 8f c7 10 03     answer from GPS to 0x8f message; ACK message
 *
 * The chip sometimes sends vendor extension messages with the prefix
 * $PEMT,100. After restart, it sends a $PEMT,100 message describing the
 * chip's configuration. Here is a sample:
 *
 * $PEMT,100,05.42g,100303,180,05,1,20,15,08,0,0,2,1*5A
 * 100 - message type
 * 05.42g - firmware version
 * 100303 - date of firmware release DDMMYY
 * 180 -  datum ID; 001 is WGS-84
 * 05 - default elevation mask; see message 0x86
 * 1 - default DOP select, 1 is auto DOP mask; see message 0x87
 * 20 - default GDOP; see message 0x87
 * 15 - default PDOP
 * 08 - default HDOP
 * 0 - Normal mode, without 1PPS
 * 0 - default position pinning control (0 disable, 1 enable)
 * 2 - altitude hold mode (0 disable, 1 always, 2 auto)
 * 1 - 2/1 satellite nav mode (0,1,2,3,4)
 *          0 disable 2/1 sat nav mode
 *          1 hold direction (2 sat)
 *          2 clock hold only (2 sat)
 *          3 direction hold then clock hold (1 sat)
 *          4 clock hold then direction hold (1 sat)
 *
 * Message $PEMT,100 could be forced with message 0x85 (restart):
 * 10 02 12 85 00 00 00 00 00 01 01 00 00 00 00 00 00 00 00 87 10 03
 * 0x85 ID, Restart
 * 0x00 restart mode (0 default, 1 hot, 2 warm, 3 cold, 4 test)
 * 0x00 test start search PRN (1-32)
 * 0x00 UTC second (0-59)
 * 0x00 UTC Minute (0-59)
 * 0x00 UTC Hour (0-23)
 * 0x01 UTC Day (1-31)
 * 0x01 UTC Month (1-12)
 * 0x0000 UTC year (1980+x, uint16)
 * 0x0000 Latitude WGS-84 (+/-900, 1/10 degree, + for N, int16)
 * 0x0000 Longtitude WGS-84 (+/-1800, 1/10 degree, + for E, int16)
 * 0x0000 Altitude WGS-84 (-1000..+18000, meters, int16)
 * 0x87 CRC
 *
 * With message 0x8e it is possible to define how often each NMEA
 * message is sent (0-255 seconds). It is possible with message 0x8e
 * to activate PEMT,101 messages that have information about time,
 * position, velocity and HDOP.
 *
 * $PEMT,101,1,02,00.0,300906190446,5002.5062,N,01427.6166,E,00259,000,0000*27
 * $PEMT,101,2,06,02.1,300906185730,5002.7546,N,01426.9524,E,00323,020,0011*26
 * 101 - message type, Compact Navigation Solution
 * 2 - position status (1,2,3,4,5,6)
 *      (1 invalid, 2 2D fix, 3 3D fix, 4 2D with DIFF, 5 3D with DIFF,
 *       6 2/1 sat degrade mode)
 * 06 - number of used satelites
 * 02.1 - DOP (00.0 no fix, HDOP 2D fix, PDOP 3D fix)
 * 300906185730 - date and time, UTC ddmmyyHHMMSS (30/09/2006 18:57:30)
 * 5002.7546,N - Latitude (degree)
 * 01426.9524,E - Longitude (degree)
 * 00323 - Altitude (323 metres)
 * 020 - heading (20 degrees from true north)
 * 0011 - speed over ground (11 metres per second); documentation says km per h
 *
 * This is an exampe of an 0x8e message that activates all NMEA sentences
 * with 1s period:
 * 10 02 12 8E 7F 01 01 01 01 01 01 01 01 00 00 00 00 00 00 15 10 03
 *
 * There is a way to probe for this chipset. When binary message 0x81 is sent:
 * 10 02 04 81 13 94 10 03
 *
 * EverMore will reply with message like this:
 * *10 *02 *0D *20 E1 00 00 *00 0A 00 1E 00 32 00 5B *10 *03
 * bytes marked with * are fixed
 * Message in reply is information about logging configuration of GPS
 *
 * Another way to detect the EverMore chipset is to send one of the messages
 * 0x85, 0x8d, 0x8e or 0x8f and check for a reply.
 * The reply message from an EverMore GPS will look like this:
 * *10 *02 *04 *38 8d c5 *10 *03
 * 8d indicates that message 0x8d was sent;
 * c5 is EverMore checksum, other bytes are fixed
 *
 * This file is Copyright (c) 2010 by the GPSD project
 * SPDX-License-Identifier: BSD-2-clause
 */

#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <math.h>

#include "gpsd.h"
#if defined(EVERMORE_ENABLE) && defined(BINARY_ENABLE)

#include "bits.h"

#define EVERMORE_CHANNELS	12

#ifdef __UNUSED__

gps_mask_t evermore_parse(struct gps_device_t * session, unsigned char *buf,
			  size_t len)
{
    unsigned char buf2[MAX_PACKET_LENGTH], *cp, *tp;
    size_t i, datalen;
    unsigned int type, used, visible, satcnt, j, k;
    double version;
    gps_mask_t mask = 0;

    /* must have two leader bytes, length, and two trailer bytes minimum */
    if (len < 5)
	return 0;

    /* time to unstuff it and discard the header and footer */
    cp = buf + 2;
    if (*cp == 0x10)
	cp++;
    datalen = (size_t) * cp++;
    datalen -= 2;

    /* prevent 'Assigned value is garbage or undefined' from scan-build */
    memset(buf2, '\0', sizeof(buf2));
    tp = buf2;
    for (i = 0; i < (size_t) datalen; i++) {
	*tp = *cp++;
	if (*tp == 0x10)
	    cp++;
	tp++;
    }
    type = (unsigned char)getub(buf2, 0);

    gpsd_log(&session->context->errout, LOG_RAW,
	     "EverMore packet type 0x%02x (%zd bytes)\n", type, tp-buf2);

    session->cycle_end_reliable = true;

    switch (type) {
    case 0x02:			/* Navigation Data Output */
	session->newdata.time = gpsd_gpstime_resolve(session,
	  (unsigned short)getleu16(buf2, 3),
	  (double)getleu32(buf2, 5) * 0.01);
	session->newdata.ecef.x = (double)getles32(buf2, 9) * 1.0,
	session->newdata.ecef.y = (double)getles32(buf2, 13) * 1.0,
	session->newdata.ecef.z = (double)getles32(buf2, 17) * 1.0,
	session->newdata.ecef.vx = (double)getles16(buf2, 21) / 10.0,
	session->newdata.ecef.vy = (double)getles16(buf2, 23) / 10.0,
	session->newdata.ecef.vz = (double)getles16(buf2, 25) / 10.0;
	ecef_to_wgs84fix(&session->newdata, &session->gpsdata.separation,
		     session->newdata.ecef.x, session->newdata.ecef.y,
		     session->newdata.ecef.z, session->newdata.ecef.vx,
		     session->newdata.ecef.vy, session->newdata.ecef.vz);
	used = (unsigned char)getub(buf2, 27) & 0x0f;
	//visible = (getub(buf2, 27) & 0xf0) >> 4;
	version = (unsigned int) getleu16(buf2, 28) / 100.0;
	/* that's all the information in this packet */
	if (used < 3)
	    session->newdata.mode = MODE_NO_FIX;
	else if (used == 3)
	    session->newdata.mode = MODE_2D;
	else {
	    session->newdata.mode = MODE_3D;
	    mask |= ALTITUDE_SET | CLIMB_SET;
	}
	mask |= TIME_SET | NTPTIME_IS | LATLON_SET | TRACK_SET | SPEED_SET
                | MODE_SET | ECEF_SET | VECEF_SET;
	if (session->subtype[0] == '\0') {
	    (void)snprintf(session->subtype, sizeof(session->subtype),
			   "%3.2f", version);
	    mask |= DEVICEID_SET;
	}
	gpsd_log(&session->context->errout, LOG_DATA,
		 "NDO 0x02: time=%.2f, lat=%.2f lon=%.2f alt=%.2f speed=%.2f track=%.2f climb=%.2f mode=%d subtype='%s\n",
		 session->newdata.time, session->newdata.latitude,
		 session->newdata.longitude, session->newdata.altitude,
		 session->newdata.speed, session->newdata.track,
		 session->newdata.climb, session->newdata.mode,
		 session->gpsdata.dev.subtype);
	return mask | CLEAR_IS | REPORT_IS;

    case 0x04:			/* DOP Data Output */
	session->newdata.time = gpsd_gpstime_resolve(session,
						     (unsigned short)getleu16(buf2, 3),
						     (double)getleu32(buf2, 5) * 0.01);
	/*
	 * We make a deliberate choice not to clear DOPs from the
	 * last skyview here, but rather to treat this as a supplement
	 * to our calculations from the visibility matrix, trusting
	 * the firmware algorithms over ours.
	 */
	session->gpsdata.dop.gdop = (double)getub(buf2, 9) * 0.1;
	session->gpsdata.dop.pdop = (double)getub(buf2, 10) * 0.1;
	session->gpsdata.dop.hdop = (double)getub(buf2, 11) * 0.1;
	session->gpsdata.dop.vdop = (double)getub(buf2, 12) * 0.1;
	session->gpsdata.dop.tdop = (double)getub(buf2, 13) * 0.1;
	switch (getub(buf2, 14)) {
	case 0:		/* no position fix */
	case 1:		/* manual calls this "1D navigation" */
	    session->gpsdata.status = STATUS_NO_FIX;
	    session->newdata.mode = MODE_NO_FIX;
	    break;
	case 2:		/* 2D navigation */
	    session->gpsdata.status = STATUS_FIX;
	    session->newdata.mode = MODE_2D;
	    break;
	case 3:		/* 3D navigation */
	    session->gpsdata.status = STATUS_FIX;
	    session->newdata.mode = MODE_3D;
	    break;
	case 4:		/* 3D navigation with DGPS */
	    session->gpsdata.status = STATUS_DGPS_FIX;
	    session->newdata.mode = MODE_3D;
	    break;
	}
	/* that's all the information in this packet */
	mask = TIME_SET | NTPTIME_IS | DOP_SET | MODE_SET | STATUS_SET;
	gpsd_log(&session->context->errout, LOG_DATA,
		 "DDO 0x04: gdop=%.2f pdop=%.2f hdop=%.2f vdop=%.2f tdop=%.2f mode=%d, status=%d mask={TIME| DOP|MODE|STATUS}\n",
		 session->gpsdata.dop.gdop, session->gpsdata.dop.pdop,
		 session->gpsdata.dop.hdop, session->gpsdata.dop.vdop,
		 session->gpsdata.dop.tdop, session->newdata.mode,
		 session->gpsdata.status);
	return mask;

    case 0x06:			/* Channel Status Output */
	session->gpsdata.skyview_time = gpsd_gpstime_resolve(session,
	    (unsigned short)getleu16(buf2, 3),
	    (double)getleu32(buf2, 5) * 0.01);
	session->gpsdata.satellites_visible = (int)getub(buf2, 9);
	gpsd_zero_satellites(&session->gpsdata);
	memset(session->gpsdata.used, 0, sizeof(session->gpsdata.used));
	if (session->gpsdata.satellites_visible > 12) {
	    gpsd_log(&session->context->errout, LOG_WARN,
		     "Warning: EverMore packet has information about %d satellites!\n",
		     session->gpsdata.satellites_visible);
	}
	if (session->gpsdata.satellites_visible > EVERMORE_CHANNELS)
	    session->gpsdata.satellites_visible = EVERMORE_CHANNELS;
	satcnt = 0;
	for (i = 0; i < (size_t) session->gpsdata.satellites_visible; i++) {
	    int prn;
	    // channel = getub(buf2, 7*i+7+3)
	    prn = (int)getub(buf2, 7 * i + 7 + 4);
	    if (prn == 0)
		continue;	/* satellite record is not valid */
	    session->gpsdata.PRN[satcnt] = prn;
	    session->gpsdata.azimuth[satcnt] =
		(int)getleu16(buf2, 7 * i + 7 + 5);
	    session->gpsdata.elevation[satcnt] =
		(int)getub(buf2, 7 * i + 7 + 7);
	    session->gpsdata.ss[satcnt] = (float)getub(buf2, 7 * i + 7 + 8);
	    /*
	     * Status bits at offset 8:
	     * bit0 = 1 satellite acquired
	     * bit1 = 1 code-tracking loop locked
	     * bit2 = 1 carrier-tracking loop locked
	     * bit3 = 1 data-bit synchronization done
	     * bit4 = 1 frame synchronization done
	     * bit5 = 1 ephemeris data collected
	     * bit6 = 1 used for position fix
	     */
	    if (getub(buf2, 7 * i + 7 + 9) & 0x40) {
		session->gpsdata.used[session->gpsdata.satellites_used++] =
		    prn;
	    }

	    satcnt++;
	}
	session->gpsdata.satellites_visible = (int)satcnt;
	/* that's all the information in this packet */
	mask = SATELLITE_SET | USED_IS;
	gpsd_log(&session->context->errout, LOG_DATA,
		 "CSO 0x06: time=%.2f used=%d visible=%d mask={TIME|SATELLITE|USED}\n",
		 session->newdata.time, session->gpsdata.satellites_used,
		 session->gpsdata.satellites_visible);
	return mask;

    case 0x08:			/* Measurement Data Output */
	/* clock offset is a manufacturer diagnostic */
	/* (int)getleu16(buf2, 9);  clock offset, 29000..29850 ?? */
	session->newdata.time = gpsd_gpstime_resolve(session,
	    (unsigned short)getleu16(buf2, 3),
	    (double)getleu32(buf2, 5) * 0.01);
	visible = (unsigned char)getub(buf2, 11);
	/*
	 * Note: This code is untested. It was written from the manual.
	 * The results need to be sanity-checked against a GPS with
	 * known-good raw decoding and the same skyview.
	 *
	 * We can get pseudo range (m), delta-range (m/s), doppler (Hz)
	 * and status for each channel from the chip.  We cannot get
	 * codephase or carrierphase.
	 */
#define SBITS(sat, s, l)	sbits((signed char *)buf, 10 + (sat*14) + s, l, false)
#define UBITS(sat, s, l)	ubits((unsigned char *)buf, 10 + (sat*14) + s, l, false)
	for (k = 0; k < visible; k++) {
	    int prn = (int)UBITS(k, 4, 5);
	    /* this is so we can tell which never got set */
	    for (j = 0; j < MAXCHANNELS; j++)
		session->gpsdata.raw.mtime[j] = 0;
	    for (j = 0; j < MAXCHANNELS; j++) {
		if (session->gpsdata.PRN[j] == prn) {
		    session->gpsdata.raw.codephase[j] = NAN;
		    session->gpsdata.raw.carrierphase[j] = NAN;
		    session->gpsdata.raw.mtime[j] = session->newdata.time;
		    session->gpsdata.raw.satstat[j] = (unsigned)UBITS(k, 24, 8);
		    session->gpsdata.raw.pseudorange[j] = (double)SBITS(k,40,32);
		    session->gpsdata.raw.deltarange[j] = (double)SBITS(k,72,32);
		    session->gpsdata.raw.doppler[j] = (double)SBITS(k, 104, 16);
		}
	    }
	}
#undef SBITS
#undef UBITS
	gpsd_log(&session->context->errout, LOG_DATA,
		 "MDO 0x04: time=%.2f mask={TIME|RAW}\n",
		 session->newdata.time);
	return TIME_SET | NTPTIME_IS | RAW_IS;

    case 0x20:			/* LogConfig Info, could be used as a probe for EverMore GPS */
	gpsd_log(&session->context->errout, LOG_DATA,
		 "LogConfig EverMore packet, length %zd\n", datalen);
	return ONLINE_SET;

    case 0x22:			/* LogData */
	gpsd_log(&session->context->errout, LOG_DATA,
		 "LogData EverMore packet, length %zd\n", datalen);
	return ONLINE_SET;

    case 0x38:			/* ACK */
	gpsd_log(&session->context->errout, LOG_PROG,
		 "EverMore command %02X ACK\n", getub(buf2, 3));
	return ONLINE_SET;

    default:
	gpsd_log(&session->context->errout, LOG_WARN,
		 "unknown EverMore packet EID 0x%02x, length %zd\n",
		 buf2[0], datalen);
	return 0;
    }
}


static gps_mask_t evermore_parse_input(struct gps_device_t *session)
{
    gps_mask_t st;

    if (session->lexer.type == EVERMORE_PACKET) {
	st = evermore_parse(session, session->lexer.outbuffer,
			    session->lexer.outbuflen);
	return st;
    }
#ifdef NMEA0183_ENABLE
    else if (session->lexer.type == NMEA_PACKET) {
	st = nmea_parse((char *)session->lexer.outbuffer, session);
	return st;
    }
#endif /* NMEA0183_ENABLE */
    else
	return 0;
}

#endif /* __UNUSED__ */

static ssize_t evermore_control_send(struct gps_device_t *session, char *buf,
				     size_t len)
{
    unsigned int crc;
    size_t i;
    char *cp;

    /* prepare a DLE-stuffed copy of the message */
    cp = session->msgbuf;
    *cp++ = 0x10;		/* message starts with DLE STX */
    *cp++ = 0x02;

    session->msgbuflen = (size_t) (len + 2);	/* len < 254 !! */
    *cp++ = (char)session->msgbuflen;	/* message length */
    if (session->msgbuflen == 0x10)
	*cp++ = 0x10;

    /* payload */
    crc = 0;
    for (i = 0; i < len; i++) {
	*cp++ = buf[i];
	if (buf[i] == 0x10)
	    *cp++ = 0x10;
	crc += buf[i];
    }

    crc &= 0xff;

    /* enter CRC after payload */
    *cp++ = crc;
    if (crc == 0x10)
	*cp++ = 0x10;

    *cp++ = 0x10;		/* message ends with DLE ETX */
    *cp++ = 0x03;

    session->msgbuflen = (size_t) (cp - session->msgbuf);

    return gpsd_write(session, session->msgbuf, session->msgbuflen);
}


static bool evermore_protocol(struct gps_device_t *session, int protocol)
{
    char tmp8;
    char evrm_protocol_config[] = {
	(char)0x84,		/* 0: msg ID, Protocol Configuration */
	(char)0x00,		/* 1: mode; EverMore binary(0), NMEA(1) */
	(char)0x00,		/* 2: reserved */
	(char)0x00,		/* 3: reserved */
    };
    gpsd_log(&session->context->errout, LOG_PROG,
	     "evermore_protocol(%d)\n", protocol);
    tmp8 = (protocol != 0) ? 1 : 0;
    /* NMEA : binary */
    evrm_protocol_config[1] = tmp8;
    return (evermore_control_send
	    (session, evrm_protocol_config,
	     sizeof(evrm_protocol_config)) != -1);
}

static bool evermore_nmea_config(struct gps_device_t *session, int mode)
/* mode = 0 : EverMore default */
/* mode = 1 : gpsd best */
/* mode = 2 : EverMore search, activate PEMT101 message */
{
    unsigned char tmp8;
    unsigned char evrm_nmeaout_config[] = {
	0x8e,			/*  0: msg ID, NMEA Message Control */
	0xff,			/*  1: NMEA sentence bitmask, GGA(0), GLL(1), GSA(2), GSV(3), ... */
	0x01,			/*  2: nmea checksum no(0), yes(1) */
	1,			/*  3: GPGGA, interval 0-255s */
	0,			/*  4: GPGLL, interval 0-255s */
	1,			/*  5: GPGSA, interval 0-255s */
	1,			/*  6: GPGSV, interval 0-255s */
	1,			/*  7: GPRMC, interval 0-255s */
	0,			/*  8: GPVTG, interval 0-255s */
	0,			/*  9: PEMT,101, interval 0-255s */
	0, 0, 0, 0, 0, 0,	/* 10-15: reserved */
    };
    gpsd_log(&session->context->errout, LOG_PROG,
	     "evermore_nmea_config(%d)\n", mode);
    tmp8 = (mode == 1) ? 5 : 1;
    /* NMEA GPGSV, gpsd  */
    evrm_nmeaout_config[6] = tmp8;	/* GPGSV, 1s or 5s */
    tmp8 = (mode == 2) ? 1 : 0;
    /* NMEA PEMT101 */
    evrm_nmeaout_config[9] = tmp8;	/* PEMT101, 1s or 0s */
    return (evermore_control_send(session, (char *)evrm_nmeaout_config,
				  sizeof(evrm_nmeaout_config)) != -1);
}

static void evermore_mode(struct gps_device_t *session, int mode)
{
    gpsd_log(&session->context->errout, LOG_PROG,
	     "evermore_mode(%d), %d\n", mode,
	     session->back_to_nmea ? 1 : 0);
    if (mode == MODE_NMEA) {
	/* NMEA */
	(void)evermore_protocol(session, 1);
	(void)evermore_nmea_config(session, 1);	/* configure NMEA messages for gpsd */
    } else {
	/* binary */
	(void)evermore_protocol(session, 0);
	session->back_to_nmea = false;
    }
}

static void evermore_event_hook(struct gps_device_t *session, event_t event)
{
    if (session->context->readonly)
	return;
    /*
     * FIX-ME: It might not be necessary to call this on reactivate.
     * Experiment to see if the holds its settings through a close.
     */
    if (event == event_identified || event == event_reactivate) {
	/*
	 * We used to run this driver in binary mode, but that has the
	 * problem that Evermore binary mode doesn't report a
	 * leap-second correction in the Navigation Data Out sentence.
	 * So, run it in NMEA mode to getbUTC corrected by firmware.
	 * Fortunately the Evermore firmware interprets binary
	 * commands in NMEA mode, so nothing else needs to change.
	 */
	(void)evermore_mode(session, 0);	/* switch GPS to NMEA mode */
	(void)evermore_nmea_config(session, 1);	/* configure NMEA messages for gpsd (GPGSV every 5s) */
	session->back_to_nmea = false;
    } else if (event == event_deactivate) {
	(void)evermore_nmea_config(session, 0);	/* configure NMEA messages to default */
    }
}

#ifdef RECONFIGURE_ENABLE
static bool evermore_speed(struct gps_device_t *session,
			   speed_t speed, char parity, int stopbits)
{
    gpsd_log(&session->context->errout, LOG_PROG,
	     "evermore_speed(%u%c%d)\n", (unsigned int)speed, parity,
	     stopbits);
    /* parity and stopbit switching aren't available on this chip */
    if (parity != session->gpsdata.dev.parity
	|| stopbits != (int)session->gpsdata.dev.parity) {
	return false;
    } else {
	unsigned char tmp8;
	unsigned char msg[] = {
	    0x89,		/*  0: msg ID, Serial Port Configuration */
	    0x01,		/*  1: bit 0 cfg for main serial, bit 1 cfg for DGPS port */
	    0x00,		/*  2: baud rate for main serial; 4800(0), 9600(1), 19200(2), 38400(3) */
	    0x00,		/*  3: baud rate for DGPS serial port; 4800(0), 9600(1), etc */
	};
	switch (speed) {
	case 4800:
	    tmp8 = 0;
	    break;
	case 9600:
	    tmp8 = 1;
	    break;
	case 19200:
	    tmp8 = 2;
	    break;
	case 38400:
	    tmp8 = 3;
	    break;
	default:
	    return false;
	}
	msg[2] = tmp8;
	return (evermore_control_send(session, (char *)msg, sizeof(msg)) !=
		-1);
    }
}

static bool evermore_rate_switcher(struct gps_device_t *session, double rate)
/* change the sample rate of the GPS */
{
    if (rate < 1 || rate > 10) {
	gpsd_log(&session->context->errout, LOG_ERROR,
		 "valid rate range is 1-10.\n");
	return false;
    } else {
	unsigned char evrm_rate_config[] = {
	    0x84,		/* 1: msg ID, Operating Mode Configuration */
	    0x02,		/* 2: normal mode with 1PPS */
	    0x00,		/* 3: navigation update rate */
	    0x00,		/* 4: RF/GPSBBP On Time */
	};
	evrm_rate_config[2] = (unsigned char)trunc(rate);
	return (evermore_control_send(session, (char *)evrm_rate_config,
				      sizeof(evrm_rate_config)) != -1);
    }
}
#endif /* RECONFIGURE_ENABLE */


/* this is everything we export */
/* *INDENT-OFF* */
const struct gps_type_t driver_evermore =
{
    .type_name      = "EverMore",		/* full name of type */
    .packet_type    = EVERMORE_PACKET,		/* lexer packet type */
    .flags	    = DRIVER_STICKY,		/* remember this */
    .trigger        = NULL, 			/* recognize the type */
    .channels       = EVERMORE_CHANNELS,	/* consumer-grade GPS */
    .probe_detect   = NULL,			/* no probe */
    .get_packet     = generic_get,		/* use generic one */
    .parse_packet   = generic_parse_input,	/* parse message packets */
    .rtcm_writer    = gpsd_write,		/* send RTCM data straight */
    .init_query     = NULL,			/* non-perturbing query */
    .event_hook     = evermore_event_hook,	/* lifetime event handler */
#ifdef RECONFIGURE_ENABLE
    .speed_switcher = evermore_speed,		/* we can change baud rates */
    .mode_switcher  = evermore_mode,		/* there is a mode switcher */
    .rate_switcher  = evermore_rate_switcher,	/* change sample rate */
    .min_cycle      = 1,			/* ignore, no rate switch */
#endif /* RECONFIGURE_ENABLE */
#ifdef CONTROLSEND_ENABLE
    .control_send   = evermore_control_send,	/* how to send a control string */
#endif /* CONTROLSEND_ENABLE */
#ifdef TIMEHINT_ENABLE
    .time_offset     = NULL,		/* no method for NTP fudge factor */
#endif /* TIMEHINT_ENABLE */
};
/* *INDENT-ON* */
#endif /* defined(EVERMORE_ENABLE) && defined(BINARY_ENABLE) */