I bought a brand new kakute F4 mini and flashed ardupilot 4.1.3 firmware， everything is ok except GPS. I use BN 880 GPS and connect to uart6， set baudrate to 38400, gps type to nema，also config gps via U center to this baudrate, the compass is good，but gps cannot be found. i changed the gps output to ublox，set gps type to ublox in mission planner， still no good. after i read some some post， I set the parameter GPS_DRV_OPTION=4, still no good. but when I changed GPS_AUTO_CONFIG=1, gps can be found. It seems only set GPS_AUTO_CONFIG=1, gps works.
Even set this，GPS is very difficult get 3D fix， it can float in the.map of mission planner for 5 minutes with no 3d fix， even never fix.
but when I connect BN880 to U center via FDTI， its 3d fix very quickly. so what the process and how ardupilot talk to gps， thats really get.me confused.
thanks for any suggestions.