permaculture

[marc@dimensional.com]

"Does anyone have information on how to open and close a chicken coop
door automatically, using a photo sensor or timer?"

A couple of suggestions:

WW Grainger has a spring loaded electric vent louver opener that could
be 
adapted to a chicken door and there are some photocell switches that
also 
can be found in Mouser, Allied, Newark and DIGI-Key electronic
catalogs.  
Many hardware, electrical and general supply houses will have 
various components you could use to control a door such as those
dark activated "turn the light on and keep the thiefs away" devices
that plug into a wall to make believe you are home.