This is a project that I did for a family member. They have chickens that live in a chicken coop. At night the coop needs to be closed so as not to allow foxes and other animals access to the chickens and their inners. For nights when the family member is not home at dusk, the door still needs to be closed. This is as simple as letting go of a string, and the hatch will close (The closing does not cause a risk to any chicken out for a late stroll).

Electronics

I designed a controller-PCB that holds a microcontroller (ESP32), a LDO, control electronics for switching of the Servo, a TIA for receiving control signals, a buzzer driver circuit and an indicator LED.

Configuration with Smartphone

I experimented with a method for configuring the closer using flashes from a smartphone screen. Described here

https://maltegruber.com/projects/blink

Mechanical Design

The number one priority was to make the unit rugged and somewhat immune to the elements. As it is to be used in a farm setting, the unit will experience some rough handling (Dirt, dust, bumps, moisture, impatience, etc).

The unit mounts to a wall mount and is easy to detach

Actuation

The slider that releases the hatch is actuated by a servo with metal gears.

Assembly

Here the device can be seen before closing, the servo in the center and the control board to the right.

Here the the closer is fully assembled. The rail system for quickly mounting it to a wall is also shown.