MAVLink Heartbeat from the GCS

Ground Control Software MAVProxy
1

Hi,

I’m currently developing a ground station to control my UAV in a GPS denied environment.

I need to ensure a failsafe is triggered when comms to my GCS is lost. From what I can gather the APM is set up to perfectly handle this if a loss of Heartbeat is detected.

What I can’t figure out is how to complete the message for the Heartbeat on the GCS side.

My HB message for the GCS so far is as such:
type = 6 (Operator Control Unit / GCS)
autopilot = 8 (No valid autopilot; e.g. a GCS)
base mode = [color=#FF0000]No idea what state the GCS should be in?[/color]
custom mode = 0
system status = [color=#FF0000]No idea again? should this be standby?[/color]
mavlink version = [color=#FF0000]Don’t understand where to even find this?[/color]

I’m writing LabVIEW drivers for this GCS so I need to know this information on byte level with reference to the packet that gets sent.

Any one have any idea?

2

Look at the source code for APM_planner on github.com/diydrones see uas.h/cc or MAVProxy

3

I couldn’t decipher the C++ code to understand exactly what bytes it send for system mode and base mode? My understanding of the magic byte is if I set it to “3” then it should work.

4

For Ardupilot it ignores the actual state. The logic triggers when there is an absence of the GCS heartbeat message for 5seconds

5

So I got the hearbeat working by setting the following values:

Magic MAVLink U8 = 3
Type = 6
Autopilot = 8
Everything else = 0

When I shut my GS off, the drone landed.