初学者： gps:GPRMC 经纬度问题

int gps_parse_line(struct gps_t *gps, char *buffer, int size)

{

float lon, lat;

char gps_status;

char n=0,m=0,f=0;

if((buffer[1] == 'G')

&&(buffer[2] == 'P')

&&(buffer[3] == 'R')

&&(buffer[4] == 'M')

&&(buffer[5] == 'C'))//GPRMC

{

for(n=0;n<100;n++)

{

if(buffer[n] == ',')

{

m ++;

if(m == 2)

{

gps_status = buffer[n+1];

}

if(m == 3)

{

if(gps_status == 'A')

{

lat =((float)(buffer[n+1])

+(float)(buffer[n+2])

+(float)(buffer[n+3])

+(float)(buffer[n+4])

+(float)(buffer[n+6])

+(float)(buffer[n+7])

+(float)(buffer[n+8])

+(float)(buffer[n+9]));

}

}

if(m == 4)

{

"N";

}

if(m == 5)

{

lon =((float)(buffer[n+1])

+(float)(buffer[n+2])

+(float)(buffer[n+3])

+(float)(buffer[n+4])

+(float)(buffer[n+5])

+(float)(buffer[n+7])

+(float)(buffer[n+8])

+(float)(buffer[n+9])

+(float)(buffer[n+10]));

}

if(m == 6)

{

"E";

}

}

}

}

gps->lat=lat;

gps->lon=lon;

return 0;

}

int gps_get(struct gps_t *gps, float *lon, float *lat)

{

*lon=gps->lon;

*lat=gps->lat;

return 0;

}

main:

int main(int argc, char *argv[])

{

float lon, lat;

struct gps_t gps;

char *buffer = "$GPRMC,013946.00,A,3202.1855,N,11849.0769,E,0.05,218.30,111105,4.5,W,A*20";

gps_parse_line(&gps, buffer, strlen(buffer));

gps_get(&gps, &lon, &lat);

printf("lon: %f, lat: %f\n", lon, lat);

getchar();

｝

为什么：      纬度：lat 开始值3202.1855     到 gps->lat=lat;

经度：lon开始值 11849.0769    到 gps->lon=lon;

lat值变为410.000000;

lon值变为477.000000;

debug时  gps->lat显示         ： gps->lat    -1.0737418e+008    float

[本帖最后由 Rick_gu 于 2014-5-29 15:40 编辑]

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