This is very small and powerful wireless controller for Canon EOS cameras. Allows for changing usual shooting parameters, suc as shutter, aperture, etc., moving focus point and, of course, taking pictures. 2 parts - Arduino Pro Mini, USB Host Shield Mini, Bluetooth Radio combination to control the camera and Android phone as a display.
http://theiopage.blogspot.com/2011/08/yanis-android-wireless-eos-controller.html