Filear.com has an informative
post on his new solar
powered Arduino controlled automatic chicken coop door opener.
He's got a 4 minute video
that helps to show what steps are needed to make something like this
work. I'm guessing it might cost over 150 dollars due to the solar
cell and back up battery. A bit complicated and somewhat expensive, but
a good choice for those out there who need this type of application and
don't want to run electrical power out to the flock.
Edited to add:
After years of research, Mark eventually settled on this automatic chicken door.
You can see
a summary of the best
chicken door alternatives and why he chose this version here.
If you're planning on
automating your coop, don't forget to pick up one of our chicken waterers. They never spill or
fill with poop, and if done right, can only need filling every few days
or weeks!