Wrong GPS coordinates


#1

Hi all,
in my application I simply activate GPS in internal mode:

adl_gpsSubscribe ( GpsHandler, 1);

ascii Latitude[50];
ascii Longitude[50];
wm_sprintf ( Latitude, GPSData->Position.latitude);
wm_sprintf ( Longitude, GPSData->Position.longitude);
wm_sprintf(Buff,“Latitude: %s ; Longitude: %s\r\n”,Latitude, Longitude);
adl_atSendResponse ( ADL_AT_UNS, Buff );

during first 5 minutes i receive the coordinates normally:

Latitude: 0803.81961 ; Longitude: 03452.69350
Latitude: 0803.81962 ; Longitude: 03452.69349
Latitude: 0803.81963 ; Longitude: 03452.69349
Latitude: 0803.81963 ; Longitude: 03452.69348
Latitude: 0803.81964 ; Longitude: 03452.69348

but after that:

Latitude: ; Longitude:
Latitude: ; Longitude:
Latitude: 0803.81942 ; Longitude: 03452.69422
Latitude: 0803.81940 ; Longitude: 03452.69423
Latitude: ; Longitude:
Latitude: 0803.81944 ; Longitude: 03452.69424
Latitude: ; Longitude:
Latitude: ; Longitude:
Latitude: 0803.81918 ; Longitude: 03452.69412
Latitude: 0803.81935 ; Longitude: 03452.69407

after some time receiving wrong coordinates, i receive them right again, and so on…

the antenna is not moving and the module(Q2501B) is being supplyed by a relyable power source.

any ideas?

Sérgio


#2

Hi sergio !

In the GPS data structure, there is the P_Fix field, which is the validity of the GPS measure. You should display it too. If the value is 0, it’s normal you don’t have GPS coordinates.

You’re modem is not moving, but sats are… GPS satelites are not geostationary ! This is maybe the reason.