I have a camera that has picture and video trigger on the same channel. As ArduPilot is not able to handle that currently I wrote a script that allows to switch between auto and manual gimbal and camera control modes. Switching to manual camera control allows to enable picture as well as video trigger.
Please let me know what you think of it and how it could be improved. I would like to ask to put into the ArduPilot lua applets directory finally.
Thanks for wanting to contribute code to ArduPilot! In order to do so it would be best to create a pull request against Ardupilot/master. It is far easier to review code and get the rights eyes on it via GitHub.