Gimbal roll/pitch/yaw mapping to RC channels

[joaoramosipl]

Describe problem solved by the proposed feature

The proposal is to add a feature to assign (more) output functions to RC channels input. For example, Landing Gear switch <-> RC channel mapping is already implemented in the Flight Control menu.
Although, I'm missing a particular gimbal roll/pitch/yaw <-> RC knob channels mapping to be able to control the gimbal either from MAVLink and/or from RC on particular channels.

Describe your preferred solution

Implement further options of assigning output functions to RC channels:
Gimbal Roll
Gimbal Pitch
Gimbal Yaw

Describe possible alternatives

Implement a reverse logic:
For each RC channel, define the output function associated to it (only those who make sense -- e.g. camera trigger, grip, parachute).

Additional context

I'm software developer and I'm willing to give support, and if you intend so, to develop modules for this to work :)
This includes, at most, adding three configuration settings on Radio for selecting:
Gimbal roll RC channel
Gimbal pitch RC channel
Gimbal yaw RC channel

[joaoramosipl]

Hello there.
Apparently, I've solved the issue by setting two AUX # RC Passthrough Channels to RC channels, and then MNT YAW, PITCH and ROLL to the according AUX Channel will solve the issue.
Although, I suggest to revise the documentation about the AUX # RC Passthrough Channels

The documentation states: "The flight controller will pass through the unmodified values from the specified channels out of AUX1/AUX2 to the connected servos/relays that drive your hardware".

I was expecting that these channels would only control hardware outputs that were assigned to AUX1, AUX2, and so on.
Although, in this case I can make the following setup:

PWM_MAIN_FUNC5 -> Gimbal Yaw
PWM_MAIN_FUNC6 -> Gimbal Pitch

MNT_MAN_YAW -> AUX1
MNT_MAN_PITCH -> AUX2

RC_MAP_AUX1 -> Channel 9
RC_MAP_AUX2 -> Channel 10

And AUX are just virtual outputs sent to the gimbal module. In this way, I can use either MAVLink and RC to control the gimbal.

I'll be developing a feature for QGroundControl/PX4 to include GUI for 6 AUX Passthrough RC Channels instead of just 2.