Enhancement: Gimbal Orientation/Mount Status Graphics

I have seen several Enhancement request here, so I hope it's OK to put this one up here; since the recent rearrangements I'm still highly confused which communication channel is best for what.

This is in relation to Randy's latest video on the Antenna Tracker, http://diydrones.com/profiles/blogs/antennatracker-v1-0-on-navio2-with-bebop2, where both the flight vehicle's and antenna tracker's heading and current WP lines are shown in MP.

This made me thinking that it would be quite cool to have an analogous feature also for a gimbal attached to the flight vehicle, i.e. that in addition to flight vehicle's lines also a line for the current heading of the gimbal would be displayed. This here is intended to discuss how that could be achieved.

I didn't really understood how that worked for the antenna tracker, the wiki didn't yielded much, and it might be that the suggested gimbal thing is already supported by MP. If so I would be happy to get my lack of knowledge filled, and what from the gimbal's side would have to be done. Specifically, I could imagine that a MAV_MOUNT_STATUS message could do that, or that the gimbal needs to appear as an additional component or system and emit an ATTITUDE message.

Any ideas how that could be achieved with the current MP, or which additions would be appropriate, would be very much appreciated.

Thx, Olli

The issue names Mission Planner and the MAV_MOUNT_STATUS and ATTITUDE messages, but no source file or test. Start by checking how the current antenna-tracker heading and waypoint lines are implemented, then determine whether gimbal orientation is already supported through those messages. Done means displaying a line for the gimbal's current heading alongside the vehicle lines.

Written by the indexing model from the issue text.