This is made with a power window motor that a friend gave to me (Thanks Jerry!) it uses a solar panel to keep the battery charged, and an ESP8266 microcontroller with built in wifi ($3.49 on ebay, requires programming) controls it. The door is a cutting board from Sams Club cut down to size, and the frame the door is mounted in is made from Aluminum C-channel from the hardware store. There are limit switches for up and down that are hooked directly to the ESP8266. They serve 2 functions, to tell the ESP8266 to turn off power to the door, and also to let the ESP8266 know if the door is open or closed (If the motor runs for a few seconds and hasn't opened or closed it will disconnect power to the motor and let me know there is a problem). There are 2 relays that the ESP8266 controls to make the motor open or close the door. The ESP8266 uses the wifi to talk to a node-red server I have running inside the house on a raspberry pi using MQTT. The node-red server is set to open the coop 10 minutes before sunrise and 10 minutes after sunset. It has been running since Father's day when my son and I installed it with no issues so far. Makes it nice on Saturday mornings to not wake up to the sound of my hens complaining they are still locked up in the chicken tractor. If anyone has questions or is interested I would be happy to share more info about it.
This is my second chicken tractor, the first I built a few years ago.
The first was much nicer but it was made to house the hens in full time and we have since given them full run of the backyard so I came up with a different tractor design. It isn't as pretty but works better for our needs. I have also come up with a great design for 2 wheels at one end and I need to take some pics or a video and I will show how it works.