- if(device->fix && LOCATION_GPS_DEVICE_SPEED_SET) {
- g_print("Speed is %f km/h", device->fix->speed);
- interpret_speed_from_gps(appdata, device->fix->speed);
+ // check for NaN before passing values
+ if(device->fix->fields & LOCATION_GPS_DEVICE_SPEED_SET) {
+ if(!isnan(device->fix->speed)) {
+ interpret_speed_from_gps(appdata, device->fix->speed);
+ }