Keeping chickens in predator-prone areas demands serious fortifications, but even the most robust coop can become a hassle without automation. That’s where [lcamtuf] steps in with his Chicken Squisher 3000, a clever DIY automatic door mechanism that opens and closes based on ambient light levels.
The chicken coop he previously built did not include a mechanism to automatically close the inner door at night, meaning that arrangements would have to be made should [lcamtuf] want to leave town for a couple of days. Not wanting to go with a commercial option for this door as that would require a good deal of modifications to the original door setup, the Chicken Squisher 3000 adds minimal parts to the existing door to now open and close the door at dawn and dusk.
Using a 12 V DC motor with a gear reduction, he was able to generate more than enough torque to open and close the thick wooden door. Instead of a complex geared rack and pinion setup, [lcamtuf] has the motor mounted to a smooth rod that then applies force across the swing of the door attached with a rod end bearing. Driving the door’s automation is an AVR16DD14 microcontroller which is used to read the NSL-A6009 light sensor. [lcamtuf] uses a DRV8231 motor driver for controlling power going to that 12 V motor with the added benefit of being able to adjust stall torque to dial in a value strong enough to overcome the wooden door’s friction, but weak enough to not endanger any of his birds. There are also buttons on the metal enclosure used to override the light sensor should he want to override it manually.
Thanks, [lcamtuf], for sending in your latest weekend project; we love the resourcefulness of using just a handful of cheap parts to make a robust solution for your coop. If you haven’t seen them yet, be sure to check out some of our other chicken coop door hacks featured before.
I love the design and simplicity, and, admittedly, the childishly hilarious project name.
Good thing chickens can’t read.
Why not use STM32 which can easily drive a 3 phase BLDC motor?
All I can ask is.. why?
If ever there was an application for a BLDC motor.. this is not it.
Unnecessary complication for something so simple.
With BLDC you can easily detect when it’s (over-)loaded, not possible to do with regular brushed DC motors.
Yes, BLDCs can do CSD (Chicken Squishing Detection).
You 100% can do squishing detection with a brushed motor. You just need a way to monitor the current. Current and torque are directly related, so higher then expected current means squishing detected.
It would hardly be possible to squish chickens then, wouldn’t it?
Some people like simple solutions. And that is not bad in any way ;)
Author here: it would double the price of the geared motor, add work, and in this application, achieve nothing useful.
Contrary to what you’re saying below, current sensing is trivial in this setup too, you can just connect another ADC pin to the low-side resistor that DRV8231 already uses for internal current sensing.
I built a chicken coop door opener a few years back. It worked great the first week or so. Then it started to get gummed up with chicken feathers and dirt. It was easier to just pay the neighbor’s kid to open and close the coop when we’re away than to make the automation bulletproof.
Good luck to this guy.
Author here. First, I think that a sealed mechanism goes a long way; there are few places that can gummed up here, and cleaning them off once a week is my plan.
Second, I more or less don’t have neighbors in a short walking distance, so it’s not an easier option here.
Looking at the photo, I wonder if you could attach a small cover/brush to push some of the debris/dirt/etc out of the way of the mechanism and reduce chances of it getting gummed up? Though as you posted if you’re planning to clean it regularly it may not be needed but a thought anyways – a very nice job here!
Thanks for the info Michal. Makes it easier to find you.
FYI: I hated you 20 years ago when you were a sysop on Wikipedia, I hate you still and my hatred will continue until I get even.
I need more backstory.
Please tell us more!
I built more or less the same thing about 5 years ago, but used a linear actuator for a drop type door instead of the open/close type. This door that swings open will end up getting stuck partially open as the chickens cover the bottom of the entry way in debris (and will also be vulnerable to snow and ice) and will require regular cleaning. With the drop type and a rubber bulb type seal it is much more resistant to this problem and gives you a nice seal for cold weather. Mine rarely needs to be cleaned unless it’s winter and I am concerned about cold air ingress.
For the door sensor, I just made a simple curtain sensor with a lens and IR LED+receiver and mirror strips on either side. It has been working well for a long time. Used a 24V actuator so that the lead acid battery backup system can keep it going without needing a generator powered circuit during outages, and those same batteries keep the single board computer, cameras, etc running as well. I am quite happy with it.
I like the old fashioned mechanisms inside the coop. When at least 2-3 chickens are roosting on the sitting bar, it drops down from weight and a rope lowers the sliding door. In the morning when the chickens get off the sitting bar, the bar raises back up and the door lifts up. Ropes, pulleys and weights. Any human can easily just open the door manually at any time for access … or disturb the chickens to get them off the bar.
I built something similar a few years ago as well. We had two cats, the old dark colored cat and the young, starving, orange cat. It sensed motion and turned on a white LED. Then sensed the color temperature of the reflected light. If it was in the red/orange spectrum, the door to the food closed.
Wouldn’t you want the door to the food to open only when the skinny orange cat was there???
From the actions of that chicken I suspect it wants a switch to open and close the door.