Coops are out of date, anyway. Chicken tractors are much more efficient.

I hate to be the negitive nacy to start off the arduino bashing, but couldn’t you do the same thing with a voltage divider on each side of the charging diode and a voltage comparator? not only does this not need a uc it doesn’t even need the phototransistor; you know since the voltage from the solar cell will be lower then the battery voltage when the sun is down?

@steve – By using an Arduino he now has the ability to add additional functionality like temperature dependency or an optical sensor to detect if a chicken is in the way or any number of other cool things.

And the Atmel micro was only a few bucks. Probably not much more than the components to build a solid state circuit version, but infinitely more versatile.

@Steve, that’s actually a really good idea comparing the battery voltage to the solar. There are a lot of possible ways to achieve the same effect. I finally chose the Arduino clone ($10.00) for a few reasons. 1. I wanted to wait a period of time after the sun went down (10 min), this is also the dead band so it wont accidentally flutter and open/close the door when a cloud passes by ect. 2. I built in a 7 second pulse to the motor so even if my limit switches break the motor will stop fairly quick and not burn up. 3. I set different light level for closing and opening for instance the door can close when the LDR is reading 200 but open when it is 600 (More deadband)

wow, that’s awesome.

Mother Earth News is running a contest for automatic chicken coop doors. You should enter this into it.