A solar tracker would be much better. It's actually really simple. You can have a photo diode that only has a small slit for light, and each time it gets dark, a motor turns on until the peephole gets sunlight again. One hard thing was making the mounting strong. We get CRAZY winds around here. My neighbor used to have 21 chickens, and after the monsoon season in July/August, he only had 1 chicken left. haha. So, I was just afraid it would break if I tried to get tricky on the first draft.
(My son wanted to click the face with the tongue sticking out)