#define _DEFAULT_SOURCE
#define _XOPEN_SOURCE
+#define _BSD_SOURCE
#include <time.h>
#include <sys/types.h>
} nmea_params[MAX_NMEA_PARAM];
static int nmea_bad_time;
-char longitude[32] = { 0 }, latitude[32] = { 0 }, course[16] = { 0 }, speed[16] = { 0 }, elevation[16] = { 0 };
+char longitude[33] = { 0 }, latitude[33] = { 0 }, course[17] = { 0 }, speed[17] = { 0 }, elevation[17] = { 0 }, satellites[3] = { 0 }, hdop[5] = { 0 };
int gps_valid = 0;
+char gps_fields = 0;
static void
nmea_txt_cb(void)
DEBUG(3, "%s: %s\n", ids[nmea_params[3].num], nmea_params[4].str);
}
+static void
+do_adjust_clock(struct tm *tm)
+{
+ char tmp[256];
+
+ strftime(tmp, 256, "%Y-%m-%dT%H:%M:%S", tm);
+ DEBUG(3, "date: %s UTC\n", tmp);
+
+ if (adjust_clock) {
+ time_t sec = timegm(tm);
+ struct timeval cur;
+
+ gettimeofday(&cur, NULL);
+
+ if ((sec < 0) || (llabs(cur.tv_sec - sec) > MAX_TIME_OFFSET)) {
+ struct timeval tv = { 0 };
+ tv.tv_sec = sec;
+ if (++nmea_bad_time > MAX_BAD_TIME) {
+ LOG("system time differs from GPS time by more than %d seconds. Using %s UTC as the new time\n", MAX_TIME_OFFSET, tmp);
+ /* only set datetime if specified by command line argument! */
+ settimeofday(&tv, NULL);
+ }
+ } else {
+ nmea_bad_time = 0;
+ }
+ }
+}
+
+static void
+parse_gps_coords(char *latstr, char *vhem, char *lonstr, char *hhem)
+{
+ float minutes;
+ float degrees;
+ float lat = strtof(latstr, NULL);
+ float lon = strtof(lonstr, NULL);
+
+ degrees = floor(lat / 100.0);
+ minutes = lat - (degrees * 100.0);
+ lat = degrees + minutes / 60.0;
+
+ degrees = floor(lon / 100.0);
+ minutes = lon - (degrees * 100.0);
+ lon = degrees + minutes / 60.0;
+
+ if (*vhem == 'S')
+ lat *= -1.0;
+ if (*hhem == 'W')
+ lon *= -1.0;
+
+ snprintf(latitude, sizeof(latitude), "%f", lat);
+ snprintf(longitude, sizeof(longitude), "%f", lon);
+
+ DEBUG(3, "position: %s %s\n", latitude, longitude);
+ gps_fields |= GPS_FIELD_LAT | GPS_FIELD_LON;
+
+ gps_timestamp();
+}
+
static void
nmea_rmc_cb(void)
{
struct tm tm;
- char tmp[256];
if (*nmea_params[2].str != 'A') {
gps_valid = 0;
&tm.tm_mday, &tm.tm_mon, &tm.tm_year) != 3) {
ERROR("failed to parse date '%s'\n", nmea_params[9].str);
}
+ else if (tm.tm_year == 0) {
+ DEBUG(4, "waiting for valid date\n");
+ return;
+ }
else {
tm.tm_year += 100; /* year starts with 1900 */
tm.tm_mon -= 1; /* month starts with 0 */
- strftime(tmp, 256, "%Y-%m-%dT%H:%M:%S", &tm);
- DEBUG(3, "date: %s UTC\n", tmp);
-
- if (adjust_clock) {
- struct timeval tv = { timegm(&tm), 0 };
- struct timeval cur;
-
- gettimeofday(&cur, NULL);
-
- if (abs(cur.tv_sec - tv.tv_sec) > MAX_TIME_OFFSET) {
- if (++nmea_bad_time > MAX_BAD_TIME) {
- LOG("system time differs from GPS time by more than %d seconds. Using %s UTC as the new time\n", MAX_TIME_OFFSET, tmp);
- /* only set datetime if specified by command line argument! */
- settimeofday(&tv, NULL);
- }
- } else {
- nmea_bad_time = 0;
- }
- }
+ do_adjust_clock(&tm);
}
if (strlen(nmea_params[3].str) < 9 || strlen(nmea_params[5].str) < 10) {
- ERROR("lat/lng have invalid string length %d<9, %d<10\n",
+ ERROR("lat/lng have invalid string length %zu<9, %zu<10\n",
strlen(nmea_params[3].str), strlen(nmea_params[5].str));
} else {
- float minutes;
- float degrees;
- float lat = strtof(nmea_params[3].str, NULL);
- float lon = strtof(nmea_params[5].str, NULL);
+ parse_gps_coords(nmea_params[3].str, nmea_params[4].str, nmea_params[5].str, nmea_params[6].str);
+ }
+}
- degrees = floor(lat / 100.0);
- minutes = lat - (degrees * 100.0);
- lat = degrees + minutes / 60.0;
+static void
+nmea_zda_cb(void)
+{
+ struct tm tm;
+
+ if (!gps_valid)
+ return;
+
+ memset(&tm, 0, sizeof(tm));
+ tm.tm_isdst = 1;
+
+ if (sscanf(nmea_params[1].str, "%02d%02d%02d",
+ &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 3) {
+ ERROR("failed to parse time '%s'\n", nmea_params[1].str);
+ return;
+ }
+
+ if ((sscanf(nmea_params[2].str, "%02d", &tm.tm_mday) != 1) ||
+ (sscanf(nmea_params[3].str, "%02d", &tm.tm_mon) != 1) ||
+ (sscanf(nmea_params[4].str, "%04d", &tm.tm_year) != 1)) {
+ ERROR("failed to parse time '%s,%s,%s'\n",
+ nmea_params[2].str, nmea_params[3].str, nmea_params[4].str);
+ return;
+ }
- degrees = floor(lon / 100.0);
- minutes = lon - (degrees * 100.0);
- lon = degrees + minutes / 60.0;
+ if (tm.tm_year == 0) {
+ DEBUG(4, "waiting for valid date\n");
+ return;
+ }
- if (*nmea_params[4].str == 'S')
- lat *= -1.0;
- if (*nmea_params[6].str == 'W')
- lon *= -1.0;
+ tm.tm_mon -= 1; /* month starts with 0 */
+ tm.tm_year -= 1900; /* full 4-digit year, tm expects years till 1900 */
- snprintf(latitude, sizeof(latitude), "%f", lat);
- snprintf(longitude, sizeof(longitude), "%f", lon);
+ do_adjust_clock(&tm);
+}
- DEBUG(3, "position: %s %s\n", latitude, longitude);
- gps_timestamp();
+static void
+nmea_gll_cb(void)
+{
+ if (*nmea_params[6].str != 'A') {
+ gps_valid = 0;
+ DEBUG(4, "waiting for valid signal\n");
+ return;
}
+
+ gps_valid = 1;
+
+ parse_gps_coords(nmea_params[1].str, nmea_params[2].str, nmea_params[3].str, nmea_params[4].str);
}
static void
{
if (!gps_valid)
return;
+ strncpy(satellites, nmea_params[7].str, sizeof(satellites));
+ strncpy(hdop, nmea_params[8].str, sizeof(hdop));
strncpy(elevation, nmea_params[9].str, sizeof(elevation));
+ gps_fields |= GPS_FIELD_SAT | GPS_FIELD_HDP | GPS_FIELD_ALT;
+ DEBUG(4, "satellites: %s\n", satellites);
+ DEBUG(4, "HDOP: %s\n", hdop);
DEBUG(4, "height: %s\n", elevation);
}
return;
strncpy(course, nmea_params[1].str, sizeof(course));
strncpy(speed, nmea_params[7].str, sizeof(speed));
+ gps_fields |= GPS_FIELD_COG | GPS_FIELD_SPD;
DEBUG(4, "course: %s\n", course);
DEBUG(4, "speed: %s\n", speed);
}
.msg = "GGA",
.cnt = 14,
.handler = nmea_gga_cb,
+ }, {
+ .msg = "GLL",
+ .cnt = 7,
+ .handler = nmea_gll_cb,
}, {
.msg = "VTG",
.cnt = 9,
.handler = nmea_vtg_cb,
+ }, {
+ .msg = "ZDA",
+ .cnt = 5,
+ .handler = nmea_zda_cb,
},
};
nmea_process(char *a)
{
char *csum;
- int cnt, i;
+ int cnt;
+ unsigned int i;
- if (strncmp(a, "$GP", 3))
+ if (strncmp(a, "$GP", 3) &&
+ strncmp(a, "$GN", 3))
return;
a++;
}
for (i = 0; i < ARRAY_SIZE(nmea_msgs); i++) {
- if (strcmp(nmea_params[0].str, nmea_msgs[i].msg))
+ if (strcmp(nmea_params[0].str, nmea_msgs[i].msg) &&
+ strcmp(nmea_params[3].str, nmea_msgs[i].msg))
continue;
if (nmea_msgs[i].cnt <= cnt)
nmea_msgs[i].handler();