How to get GLOBAL_POSITION_INT_COV streamed

MAVLink
1

Hi!

I want to get the GLOBAL_POSITION_IN_COV streamed. It is a message in the common.xml set: GLOBAL_POSITION_IN_COV

However I see that it is not currently being streamed via the mavlink inspector in QGC and I do not see it being used in any of the modes in mavlink_main.cpp.

So I figure I must add it via a custom build of PX4. Is this correct?

I am reading the documentation " Adding Standard MAVLink Definitions (Messages/Commands)"

I am a bit confused as I read:

New standard definitions are added first to development.xml , and then moved to common.xml following review and prototyping, and acceptance by the MAVLink team.
…
During development you can add your definitions to PX4-Autopilot/src/modules/mavlink/mavlink/message_definitions/v1.0/development.xml (or pull them from MAVLink).

I don’t understand - is this for custom mavlink messages? Why should I be using deveopment.xml if the GLOBAL_POSITION_IN_COV is already in the common.xml? Should I be writing a GLOBAL_POSITION_IN_COV.hpp or should this be built for me?

What I have done is that I have added the following to Normal, USB, and CUSTOM modes

configure_stream_local(“GLOBAL_POSITION_INT_COV”, 5.0f);

But have been unsuccessful so far, so I think I need to be doing something more.

2

I think the docs you’re reading are how to get a message into the MAVLink standard. In your case, you just want to stream a message that is already in the standard.

Now checking PX4, it looks like this message is not implemented, see:

So, you will have to follow the implementation of any other message and adapt it for this message.