Hi Mark,
Thank you for your reply. I suspected that the Ardupilot mega was overkill but there are so many other Arduino boards, I don't know which one is the best match for this purpose. Since there is a 3-Axis gimbal feature of this board, it seemed like a solution at least.
I'm planning a project with another friend. He is building an octocopter and I'm building a gimbal to attach to the copter. The gimbal will also be used by itself on a camera jib as well as a 50 foot high camera mast so I need it to be a standalone rig that's easily removable from the helicopter so I can quickly mount it to other rigs. I'm planning to have a dedicated radio controller for the gimbal as well.
The closed loop method you mentioned sounds like exactly what I need. Ideally I want the gimbal to maintain a level orientation while flying but still allow manual position changes via the radio controller.
I'm also shooting for simplicity, as I'm not an electronics engineer nor do I have any serious code writing skills (unless you consider Javascript and HTML to be serious code - I'm guessing no). I'm comfortable navigating config files to change parameters but I'm hoping to find a hardware and firmware solution that's already basically set up and at most, only needs a little tweaking. As I understand, the Ardupilot's last few firmware revisions include 3-axis gimbal control. It appears to be fairly plug and play.
Does the ardupilot firmware work on other boards? Is there a less overkill board/firmware combo that's up to this task?
In your response you mentioned using an Arduino plus a small sensor board. Which Arduino board did you have in mind?
Thank you again for your response. I truly appreciate your time.