From 24673ed38d3d0b60820771de12c617c3d16cf081 Mon Sep 17 00:00:00 2001 From: Guido Guenther Date: Sun, 17 Aug 2008 14:37:40 +0200 Subject: [PATCH] parse nmea long and lat from GPGGA messages useful for receivers like the DE8100 --- src/gps_functions.c | 60 +++++++++++++++++++++++++++++++++++++++++--------- 1 files changed, 49 insertions(+), 11 deletions(-) diff --git a/src/gps_functions.c b/src/gps_functions.c index bafbc18..0380431 100644 --- a/src/gps_functions.c +++ b/src/gps_functions.c @@ -439,21 +439,59 @@ parse_nmea_rmc(char *nmea) void parse_nmea_gga(char *nmea) { - gchar **array; - - - array = g_strsplit(nmea,",",0); +#define GGA_UTC 1 +#define GGA_LAT 2 +#define GGA_LON 4 +#define GGA_QUAL 6 +#define GGA_SATS 7 +#define GGA_HDOP 8 +#define GGA_ALT 9 + gchar **array; + gchar lat_dec[3], lon_dec[4]; + double lat_min, lat, lon_min, lon; + gint qual = 0; + gboolean valid = TRUE; + + array = g_strsplit(nmea, ",", 0); + gpsdata->satellites_used = atoi(array[GGA_SATS]); + + if (strlen(array[GGA_LAT]) == 9) { + strncpy(lat_dec, array[GGA_LAT], 2); + lat_dec[2]='\0'; + lat_min = atof(array[GGA_LAT]+2); + lat = atof(lat_dec) + (lat_min/60); + if (strcmp(array[GGA_LAT+1], "S")==0) + lat = -lat; + } else { + valid = FALSE; + lat = 0.0; + } - - gpsdata->satellites_used = atoi(array[7]); - - if(atoi(array[6])>0) - { - gpsdata->hdop = atof(array[8]); - gpsdata->fix.altitude = atof(array[9]); + if (strlen(array[GGA_LON]) == 10) { + strncpy(lon_dec, array[GGA_LON], 3); + lon_dec[3]='\0'; + lon_min = atof(array[GGA_LON]+3); + lon = atof(lon_dec) + (lon_min/60); + if (strcmp(array[GGA_LON+1],"W")==0) + lon = -lon; + } else { + valid = FALSE; + lon = 0.0; } + qual = atoi(array[GGA_QUAL]) > 0; + if(qual) { + gpsdata->hdop = atof(array[GGA_HDOP]); + gpsdata->fix.altitude = atof(array[GGA_ALT]); + if (valid) { + gpsdata->fix.latitude = lat; + gpsdata->fix.longitude = lon; + gpsdata->fix.speed = 0; + gpsdata->fix.track = 0; + gpsdata->valid = TRUE; + } + } g_strfreev(array); } -- 1.5.6.3