2 * Copyright © 2009 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22 #include <sys/types.h>
25 #define AO_GPS_NUM_SAT_MASK (0xf << 0)
26 #define AO_GPS_NUM_SAT_SHIFT (0)
28 #define AO_GPS_VALID (1 << 4)
29 #define AO_GPS_RUNNING (1 << 5)
36 int32_t latitude; /* degrees * 10⁷ */
37 int32_t longitude; /* degrees * 10⁷ */
38 int16_t altitude; /* m */
39 uint16_t ground_speed; /* cm/s */
40 uint8_t course; /* degrees / 2 */
41 uint8_t hdop; /* * 5 */
42 int16_t climb_rate; /* cm/s */
43 uint16_t h_error; /* m */
44 uint16_t v_error; /* m */
48 ao_mutex_get(uint8_t *mutex)
53 ao_mutex_put(uint8_t *mutex)
69 sprintf (line, "\\%02x", ((int) c) & 0xff);
71 sprintf (line, "%c", c);
73 write(1, line, strlen(line));
76 #define QUEUE_LEN 4096
78 static char input_queue[QUEUE_LEN];
79 int input_head, input_tail;
83 check_sirf_message(char *from, uint8_t *msg, int len)
85 uint16_t encoded_len, encoded_cksum;
90 if (msg[0] != 0xa0 || msg[1] != 0xa2) {
91 printf ("bad header\n");
98 if (msg[len-1] != 0xb3 || msg[len-2] != 0xb0) {
99 printf ("bad trailer\n");
102 encoded_len = (msg[2] << 8) | msg[3];
104 if (encoded_len != len - 8) {
105 printf ("length mismatch (got %d, wanted %d)\n",
106 len - 8, encoded_len);
109 encoded_cksum = (msg[len - 4] << 8) | msg[len-3];
111 for (i = 4; i < len - 4; i++)
112 cksum = (cksum + msg[i]) & 0x7fff;
113 if (encoded_cksum != cksum) {
114 printf ("cksum mismatch (got %04x wanted %04x)\n",
115 cksum, encoded_cksum);
143 int16_t heading_rate;
149 #define get_u8(u) u = (msg[off]); off+= 1
150 #define get_u16(u) u = (msg[off] << 8) | (msg[off + 1]); off+= 2
151 #define get_u32(u) u = (msg[off] << 24) | (msg[off + 1] << 16) | (msg[off+2] << 8) | (msg[off+3]); off+= 4
174 get_u16(heading_rate);
181 printf ("Geodetic Navigation Data (41):\n");
182 printf ("\tNav valid %04x\n", nav_valid);
183 printf ("\tNav type %04x\n", nav_type);
184 printf ("\tWeek %d\n", week);
185 printf ("\tTOW %d\n", tow);
186 printf ("\tyear %d\n", year);
187 printf ("\tmonth %d\n", month);
188 printf ("\tday %d\n", day);
189 printf ("\thour %d\n", hour);
190 printf ("\tminute %d\n", minute);
191 printf ("\tsecond %g\n", second / 1000.0);
192 printf ("\tsats: %08x\n", sat_list);
193 printf ("\tlat: %g\n", lat / 1.0e7);
194 printf ("\tlon: %g\n", lon / 1.0e7);
195 printf ("\talt_ell: %g\n", alt_ell / 100.0);
196 printf ("\talt_msll: %g\n", alt_msl / 100.0);
197 printf ("\tdatum: %d\n", datum);
198 printf ("\tground speed: %g\n", sog / 100.0);
199 printf ("\tcourse: %g\n", cog / 100.0);
200 printf ("\tclimb: %g\n", climb_rate / 100.0);
201 printf ("\theading rate: %g\n", heading_rate / 100.0);
202 printf ("\th error: %g\n", h_error / 100.0);
203 printf ("\tv error: %g\n", v_error / 100.0);
204 printf ("\tt error: %g\n", t_error / 100.0);
205 printf ("\th vel error: %g\n", h_v_error / 100.0);
208 printf ("%s %4d:", from, encoded_len);
209 for (i = 4; i < len - 4; i++) {
210 if (((i - 4) & 0xf) == 0)
212 printf (" %3d", msg[i]);
218 static uint8_t sirf_message[4096];
219 static int sirf_message_len;
220 static uint8_t sirf_in_message[4096];
221 static int sirf_in_len;
224 ao_serial_getchar(void)
229 while (input_head == input_tail) {
231 input_tail = read(ao_gps_fd, input_queue, QUEUE_LEN);
232 if (input_tail < 0) {
233 if (errno == EINTR || errno == EAGAIN)
242 c = input_queue[input_head];
243 input_head = (input_head + 1) % QUEUE_LEN;
245 if (sirf_in_len || uc == 0xa0) {
246 if (sirf_in_len < 4096)
247 sirf_in_message[sirf_in_len++] = uc;
249 check_sirf_message("recv", sirf_in_message, sirf_in_len);
258 ao_serial_putchar(char c)
261 uint8_t uc = (uint8_t) c;
263 if (sirf_message_len || uc == 0xa0) {
264 if (sirf_message_len < 4096)
265 sirf_message[sirf_message_len++] = uc;
267 check_sirf_message("send", sirf_message, sirf_message_len);
268 sirf_message_len = 0;
272 i = write(ao_gps_fd, &c, 1);
274 if ((uint8_t) c == 0xb3 || c == '\r') {
275 static const struct timespec delay = {
277 .tv_nsec = 100 * 1000 * 1000
280 // nanosleep(&delay, NULL);
284 if (i < 0 && (errno == EINTR || errno == EAGAIN))
291 #define AO_SERIAL_SPEED_4800 0
292 #define AO_SERIAL_SPEED_57600 1
295 ao_serial_set_speed(uint8_t speed)
298 struct termios termios;
301 tcgetattr(fd, &termios);
303 case AO_SERIAL_SPEED_4800:
304 cfsetspeed(&termios, B4800);
306 case AO_SERIAL_SPEED_57600:
307 cfsetspeed(&termios, B57600);
310 tcsetattr(fd, TCSAFLUSH, &termios);
311 tcflush(fd, TCIFLUSH);
314 #include "ao_gps_print.c"
321 printf ("%02d:%02d:%02d",
322 ao_gps_data.hour, ao_gps_data.minute,
324 printf (" nsat %d %svalid",
325 ao_gps_data.flags & AO_GPS_NUM_SAT_MASK,
326 ao_gps_data.flags & AO_GPS_VALID ? "" : "not ");
327 printf (" lat %g lon %g alt %d",
328 ao_gps_data.latitude / 1.0e7,
329 ao_gps_data.longitude / 1.0e7,
330 ao_gps_data.altitude);
331 printf (" speed %g climb %g course %d",
332 ao_gps_data.ground_speed / 100.0,
333 ao_gps_data.climb_rate / 100.0,
334 ao_gps_data.course * 2);
335 printf (" hdop %g h_error %d v_error %d",
336 ao_gps_data.hdop / 5.0,
337 ao_gps_data.h_error, ao_gps_data.v_error);
342 ao_gps_open(const char *tty)
344 struct termios termios;
347 fd = open (tty, O_RDWR);
351 tcgetattr(fd, &termios);
353 cfsetspeed(&termios, B4800);
354 tcsetattr(fd, TCSAFLUSH, &termios);
357 tcflush(fd, TCIFLUSH);
362 main (int argc, char **argv)
364 char *gps_file = "/dev/ttyUSB0";
366 ao_gps_fd = ao_gps_open(gps_file);