Having your own egg laying chickens in times of food scandals like the latest dioxin scandal is a fine thing. Although these chickens from my little cousin on the pictures here are not some fancy bred “hybrid chicken”, they lay almost one egg a day during summer and live a happy life. They have a large area to peck and paw and sleep inside a beautiful coop.However, keeping chickens has one major drawback: You have to get up with them in the early morning and open the door at the coop. Everyday. Including Sundays and holidays. It can be quite tedious sometimes. That’s why my litte cousin asked me to construct an automated door for his chicken coop that opens at the break of dawn and closes at dusk.…The actuator raising and lowering the door is a strong gear motor from a wiper. I bought it at a local scrap merchant for 10 euros. The motor includes a worm drive so it holds its position when powered off.Two switches in a parallel arrangement recognize when the door is open or closed. Because of the parallel arrangement, the microcontroller can only recognize that the door has reached an end position but not which one. This mean saves one input/output controller.As sensor for the brightness, I use a photoconductive cell.The whole system gets its power from a 12 V / 7 Ah accu. It can be charged by a small 2.1 W solar panel.