Use APM firmware and ground station no need to modify - No onboard compass which makes this version ideal for use with multicopters and rovers -8-CH output and 8-CH input - Can connect to external GPS compass telemetry system and PM module - 12-CH function interface - Size: 35*35mm GPS module MiniAPM Features: -Adopts Ublox NEO-6M chip; -With HMC5883L compass module; -For multi-rotors; -Plug and play with installation hole easy to mount. MinimOSD features: APM has an companion OSD board called MinimOSD. It reads all the MAVLink data in the APM telemetry stream and overlays it on the video stream if you're using an on-board camera and wireless video transmitter. This is useful if you're flying in First Person View (FPV) mode or don't want to use a laptop at the field to see your telemetry data in the Mission Planner.