Im operating UAV plane, controlled by Pixhawk for aerial imagery purpose. Pixhawk is controlling camera shutter by one channel. But this camera control has just two positions - shutter pushed and shutter released. Would it be possible to control camera by three positions command? I mean following positions: Lens closed, Lens open/shutter released, Shutter pushed. It would be great to have a possibility to close lens before landing (and during take-off) and Canon camera with CHDK can do it easy. Now I have to control these three statuses by two channels, but why not to control three positions by just one channel? Does it exist such a functionality in current arduplane software or is there, at least, any not complicated way how to customize it?