between the Plane And GCS. There are so many different MAVLink messages which can be used
to send GPS Coordinates, Altitudes...
Crossbow AAT needs both these 2 MAVLink messages to track.
MAVLINK_MSG_ID_GPS_RAW_INT
MAVLINK_MSG_ID_GLOBAL_POSITION_INT
If the Crossbow AAT receives some correct MAVLink data packs (Heartbeat?) but not able to find
the above 2 messages, it will display "DLink:1% msg?" to remind you to check if the above 2
messages are sent at 1Hz or a higher frequency.
In Crossbow AAT, If you choose menu "Protocol->ALT=BARO",
MAVLINK_MSG_ID_GLOBAL_POSITION_INT.relative_alt
is used as the data source of the
altitude. This works for most ArduPilots. (APM), and MFD Crosshair AP.
You can check "FlightInfo-> ALT/BARO" to read the current GPS-ALT and Baro-Alt.
Crossbow uses "Baro" Alt to track.
Another option is "Protocol->ALT=GPS". In this case,
MAVLINK_MSG_ID_GPS_RAW_INT
will be
used as the data source of the altitude. This works for most PIX4 Flight Controllers.
In this case, "FlightInfo-> ALT/BARO" are both from
MAVLINK_MSG_ID_GPS_RAW_INT
message.
We recommend our users to set the update frequency of the above 2 messages higher to get
better tracking performance. The method varies from different Flight Controllers. Take the
ArduPilot Mega as an example, you can search for string"SR1_" in Mission Planner "All
parameters List" to get a table of MAVLink messages updating frequency for Telemetry1 port.
Please set SR1_POSITION to 5Hz or higher in this case. 0=Disable.
TroubleShooting:My DataRadio doesn't work with Crossbow. Only VLink:0% is displayed
1. Check if the tracker is receiving data from your date radio. Check Menu item
"Factory->CoreData->RX". This number will increase when the tracker receives any data from
U3RX (Datalink port) or U2RX(External GPS port). If the RX doesn't increate at all, please check
your cables again and make sure your DataRadio is sending out date on its TX wire.
2. Check menu "BaudRate" again to make sure you are using a proper baudrate, especially after
you apply a new firmware.
5. AAT menu operation guide
After power on the screen shows main parameters of the current status.
