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
|
/*
* Copyright © 2009 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#define AO_GPS_TEST
#include "ao_host.h"
#include <termios.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define AO_GPS_NUM_SAT_MASK (0xf << 0)
#define AO_GPS_NUM_SAT_SHIFT (0)
#define AO_GPS_VALID (1 << 4)
#define AO_GPS_RUNNING (1 << 5)
struct ao_gps_data {
uint8_t hour;
uint8_t minute;
uint8_t second;
uint8_t flags;
int32_t latitude; /* degrees * 10⁷ */
int32_t longitude; /* degrees * 10⁷ */
int16_t altitude; /* m */
uint16_t ground_speed; /* cm/s */
uint8_t course; /* degrees / 2 */
uint8_t hdop; /* * 5 */
int16_t climb_rate; /* cm/s */
uint16_t h_error; /* m */
uint16_t v_error; /* m */
};
void
ao_mutex_get(uint8_t *mutex)
{
}
void
ao_mutex_put(uint8_t *mutex)
{
}
static int
ao_gps_fd;
static void
ao_dbg_char(char c)
{
char line[128];
line[0] = '\0';
if (c < ' ') {
if (c == '\n')
sprintf (line, "\n");
else
sprintf (line, "\\%02x", ((int) c) & 0xff);
} else {
sprintf (line, "%c", c);
}
write(1, line, strlen(line));
}
#define QUEUE_LEN 4096
static char input_queue[QUEUE_LEN];
int input_head, input_tail;
static void
check_sirf_message(char *from, uint8_t *msg, int len)
{
uint16_t encoded_len, encoded_cksum;
uint16_t cksum;
uint8_t id;
int i;
if (msg[0] != 0xa0 || msg[1] != 0xa2) {
printf ("bad header\n");
return;
}
if (len < 7) {
printf("short\n");
return;
}
if (msg[len-1] != 0xb3 || msg[len-2] != 0xb0) {
printf ("bad trailer\n");
return;
}
encoded_len = (msg[2] << 8) | msg[3];
id = msg[4];
if (encoded_len != len - 8) {
printf ("length mismatch (got %d, wanted %d)\n",
len - 8, encoded_len);
return;
}
encoded_cksum = (msg[len - 4] << 8) | msg[len-3];
cksum = 0;
for (i = 4; i < len - 4; i++)
cksum = (cksum + msg[i]) & 0x7fff;
if (encoded_cksum != cksum) {
printf ("cksum mismatch (got %04x wanted %04x)\n",
cksum, encoded_cksum);
return;
}
id = msg[4];
if (id == 41) {
int off = 4;
uint8_t id;
uint16_t nav_valid;
uint16_t nav_type;
uint16_t week;
uint32_t tow;
uint16_t year;
uint8_t month;
uint8_t day;
uint8_t hour;
uint8_t minute;
uint16_t second;
uint32_t sat_list;
int32_t lat;
int32_t lon;
int32_t alt_ell;
int32_t alt_msl;
int8_t datum;
uint16_t sog;
uint16_t cog;
int16_t mag_var;
int16_t climb_rate;
int16_t heading_rate;
uint32_t h_error;
uint32_t v_error;
uint32_t t_error;
uint16_t h_v_error;
#define get_u8(u) u = (msg[off]); off+= 1
#define get_u16(u) u = (msg[off] << 8) | (msg[off + 1]); off+= 2
#define get_u32(u) u = (msg[off] << 24) | (msg[off + 1] << 16) | (msg[off+2] << 8) | (msg[off+3]); off+= 4
get_u8(id);
get_u16(nav_valid);
get_u16(nav_type);
get_u16(week);
get_u32(tow);
get_u16(year);
get_u8(month);
get_u8(day);
get_u8(hour);
get_u8(minute);
get_u16(second);
get_u32(sat_list);
get_u32(lat);
get_u32(lon);
get_u32(alt_ell);
get_u32(alt_msl);
get_u8(datum);
get_u16(sog);
get_u16(cog);
get_u16(mag_var);
get_u16(climb_rate);
get_u16(heading_rate);
get_u32(h_error);
get_u32(v_error);
get_u32(t_error);
get_u16(h_v_error);
printf ("Geodetic Navigation Data (41):\n");
printf ("\tNav valid %04x\n", nav_valid);
printf ("\tNav type %04x\n", nav_type);
printf ("\tWeek %d\n", week);
printf ("\tTOW %d\n", tow);
printf ("\tyear %d\n", year);
printf ("\tmonth %d\n", month);
printf ("\tday %d\n", day);
printf ("\thour %d\n", hour);
printf ("\tminute %d\n", minute);
printf ("\tsecond %g\n", second / 1000.0);
printf ("\tsats: %08x\n", sat_list);
printf ("\tlat: %g\n", lat / 1.0e7);
printf ("\tlon: %g\n", lon / 1.0e7);
printf ("\talt_ell: %g\n", alt_ell / 100.0);
printf ("\talt_msll: %g\n", alt_msl / 100.0);
printf ("\tdatum: %d\n", datum);
printf ("\tground speed: %g\n", sog / 100.0);
printf ("\tcourse: %g\n", cog / 100.0);
printf ("\tclimb: %g\n", climb_rate / 100.0);
printf ("\theading rate: %g\n", heading_rate / 100.0);
printf ("\th error: %g\n", h_error / 100.0);
printf ("\tv error: %g\n", v_error / 100.0);
printf ("\tt error: %g\n", t_error / 100.0);
printf ("\th vel error: %g\n", h_v_error / 100.0);
} else {
return;
printf ("%s %4d:", from, encoded_len);
for (i = 4; i < len - 4; i++) {
if (((i - 4) & 0xf) == 0)
printf("\n ");
printf (" %3d", msg[i]);
}
printf ("\n");
}
}
static uint8_t sirf_message[4096];
static int sirf_message_len;
static uint8_t sirf_in_message[4096];
static int sirf_in_len;
char
ao_serial_getchar(void)
{
char c;
uint8_t uc;
while (input_head == input_tail) {
for (;;) {
input_tail = read(ao_gps_fd, input_queue, QUEUE_LEN);
if (input_tail < 0) {
if (errno == EINTR || errno == EAGAIN)
continue;
perror ("getchar");
exit (1);
}
input_head = 0;
break;
}
}
c = input_queue[input_head];
input_head = (input_head + 1) % QUEUE_LEN;
uc = c;
if (sirf_in_len || uc == 0xa0) {
if (sirf_in_len < 4096)
sirf_in_message[sirf_in_len++] = uc;
if (uc == 0xb3) {
check_sirf_message("recv", sirf_in_message, sirf_in_len);
sirf_in_len = 0;
}
}
return c;
}
void
ao_serial_putchar(char c)
{
int i;
uint8_t uc = (uint8_t) c;
if (sirf_message_len || uc == 0xa0) {
if (sirf_message_len < 4096)
sirf_message[sirf_message_len++] = uc;
if (uc == 0xb3) {
check_sirf_message("send", sirf_message, sirf_message_len);
sirf_message_len = 0;
}
}
for (;;) {
i = write(ao_gps_fd, &c, 1);
if (i == 1) {
if ((uint8_t) c == 0xb3 || c == '\r') {
static const struct timespec delay = {
.tv_sec = 0,
.tv_nsec = 100 * 1000 * 1000
};
tcdrain(ao_gps_fd);
// nanosleep(&delay, NULL);
}
break;
}
if (i < 0 && (errno == EINTR || errno == EAGAIN))
continue;
perror("putchar");
exit(1);
}
}
#define AO_SERIAL_SPEED_4800 0
#define AO_SERIAL_SPEED_57600 1
static void
ao_serial_set_speed(uint8_t speed)
{
int fd = ao_gps_fd;
struct termios termios;
tcdrain(fd);
tcgetattr(fd, &termios);
switch (speed) {
case AO_SERIAL_SPEED_4800:
cfsetspeed(&termios, B4800);
break;
case AO_SERIAL_SPEED_57600:
cfsetspeed(&termios, B57600);
break;
}
tcsetattr(fd, TCSAFLUSH, &termios);
tcflush(fd, TCIFLUSH);
}
#include "ao_gps_print.c"
#include "ao_gps.c"
void
ao_dump_state(void)
{
double lat, lon;
printf ("%02d:%02d:%02d",
ao_gps_data.hour, ao_gps_data.minute,
ao_gps_data.second);
printf (" nsat %d %svalid",
ao_gps_data.flags & AO_GPS_NUM_SAT_MASK,
ao_gps_data.flags & AO_GPS_VALID ? "" : "not ");
printf (" lat %g lon %g alt %d",
ao_gps_data.latitude / 1.0e7,
ao_gps_data.longitude / 1.0e7,
ao_gps_data.altitude);
printf (" speed %g climb %g course %d",
ao_gps_data.ground_speed / 100.0,
ao_gps_data.climb_rate / 100.0,
ao_gps_data.course * 2);
printf (" hdop %g h_error %d v_error %d",
ao_gps_data.hdop / 5.0,
ao_gps_data.h_error, ao_gps_data.v_error);
printf("\n");
}
int
ao_gps_open(const char *tty)
{
struct termios termios;
int fd;
fd = open (tty, O_RDWR);
if (fd < 0)
return -1;
tcgetattr(fd, &termios);
cfmakeraw(&termios);
cfsetspeed(&termios, B4800);
tcsetattr(fd, TCSAFLUSH, &termios);
tcdrain(fd);
tcflush(fd, TCIFLUSH);
return fd;
}
int
main (int argc, char **argv)
{
char *gps_file = "/dev/ttyUSB0";
ao_gps_fd = ao_gps_open(gps_file);
if (ao_gps_fd < 0) {
perror (gps_file);
exit (1);
}
ao_gps_setup();
ao_gps();
}
|