I am looking to build a basic automatic chicken coop door that will open and close on a timer.
We are thinking of using a linear actuator, a timer, an electromagnetic relay and a 12v battery (chicken coop is far away from mains power). I am new to electronics and don’t have any experience building this sort of thing, but am keen to learn and get some advice.
Can you please recommend some products that will enable us to put together a coop door that will open and close automatically?
The functions and specs it will need to have are:
linear actuator will need to have approx 300mm retractable distance (minimum 250mm), and preferably weatherproof-ish (will be under coop’s eaves but outdoors).
able to operate on a battery (battery and other electronics can be inside the coop and out of the weather, it would just be the door mechanism that’s outside)
timer which can switch polarities every 12 hours, but is programmable (eg longer days in summer, shorter in winter)
Here’s a video of what we are imagining - I’d like to make it a bit neater than this one, and it would need to be on a battery, but a good indication of what we had in mind: https://m.youtube.com/watch?v=Jyh4noiO9v4
Very interesting, if not too far away from 240V you may want to use a power supply instead to ensure that you’ve got constant power to the device. If you wanted to use a battery, however, you’ve got two major options. You could use Lithium batteries of some description, that generally have better performance, although if you need something more weatherproof I’d look into SLA (Sealed Lead-Acid) batteries, similar to that from a car (we don’t supply these ourselves as they don’t suit the logistics process we use, but they’d provide more than enough power). As for a programmable device that you can easily use in order to perform that application, I’d go with an Arduino Uno personally, then just adjust the length of the delay between moving which should be able to go for a significantly long time, you can also expand the project and use it for a bunch of other sensors like photoresistors, fans, thermometers and similar so that you can get alerts or something similar when the conditions aren’t suitable. Personally, I’d see about adding housing to a stepper motor with a vertical rack and pinion system, or a lead screw rather than using a linear actuator, as it’s much less expensive if damaged and much easier to weatherproof. I’d check the weight of your door to ensure that the power screw can drive it. But this should be a good place to start looking.
(This also has an in-built regulator which you can get 5V out for your Arduino as well as to control the stepper)
Also, people have done similar projects to this in the past, I’d take a look at these ones too:
Have a great day! And please let us know if you need anything.