Electronics > Projects, Designs, and Technical Stuff

Automatic chicken door time input (low power, simple)

<< < (4/10) > >>

soldar:
Sunrise and sunset times can be easily approximated with a simple function but from one day to the next there can be a big difference in light if one day is clear and the other is heavily overcast. There can be an hour's difference in light conditions. If you want to get fancy you can combine ambient light, sunrise/set times, temperature, etc. to decide.

If you really want to use minimal electric power you could power it with compressed air from a bottle and just need a couple valves which would use close to nothing. You refill the bottle with compressed once or twice a month. This has the advantage of not destroying the chicken coop with a fire. Maybe an explosion but not a fire :)

Amper:
I have thought about making a guillotine door in the very beginning but its just not really doable in my place. Its just to large ( 40x50cm) because of our dog (leonberger, size and weight close to a human). Also while locking mechanics are simple im afraid of something getting stuck. Just a little dirt or some water making the wood swell will be enough to jam the thing completely. Then the limit switches wont help either, the winch motor will be pulling as hard as it can for as long as the power is there or in case of grid power it might get hot. This means without current monitoring and redundant limit switches there is no way. I want this thing to be maintainance free as much as possible, not checking for stuck wood pieces every few days. The mechanics have also been working with absolutely no problem for more than 500 days now, im quite happy with it. No limit switches that fail,  no string getting tangled. With a winch if the limit switch will fail the thing will wind up the other way and the door will stay open. If the String breaks in the wrong moment and i have a heavy locking door it will chop a chickens head off easily. My dad had chicken as well when he was a child and it was a guillotine style door. It was fixed by a string and some day he held it in his hand and slipped  off in the right time to have some tasty soup the next day. I dont want to be responsible for that.

The time calculating by table and functions is all well and dandy but only when you live on a perfect sphere. We have hills nearby, large trees, there is weather happening and many many other factors. As soldar said, its not that easy sadly. Combining many factors would be nice but to be honest i wouldnt be sure how to do that in a predictable fashion. I could either use simple logig "when brighter than y and time after x .... open door" but in that case i could just go with the one real variable light and ditch the rest of it. It would need some "intelligent" calculating and predicting but i think thats a bit to much work to implement and especially verify for such a small project. You can see in the video posted last how simple other people go about it. Im pretty sure he didnt even think about light threshholds and hysteresis like me, he just used "a light switch" and put two building timers behind it. Seems to work.

About sensors to monitor the animals im not sure how to do it and if its really possible. We have scratched that topic when talking about rfid. A time of flight sensor can only tell me if there is some animal standing in the doorway. How should it know in which direction it will hop? What about small birds flying in, what about two chicken in the doorway at the same  time. It would need a tunnel barely enough to fit one of them so its possible to determine exactly whats going on. Same applies to having a scale in the ground besides the heavy dog and water + dirt. Sadly not a practical solution. Weighing the ladder they sit on would imply that they weigh the exact same every day. We have roughly 10 of them so it comes down to a weight change of 10%. Assuming one is sitting outside and the other 9 have eaten a lot in the day, one will be locked out. Assuming one is sitting in the nest on the eggs, the door might not close all night.  Wifi and Bluetooth are cool but i really f***** hate IOT for security reasons. Our living room is right next to it  and if i do need to check manually anyways i can just look at the door or have some led light up if there is a failure thats detectable. Also the Power management would be completely out of the window at that time.
Sadly things are not as simple as just throwing sensors on the problems ^^

I have thought about storing compressed air a lot actually I really like the idea. Problem is if i will use high pressure like the usual 8-10 atmospheres of an air compressor it will be empty very quickly through even small leaks and a refill will mean my mother needs to get the compressor set up and refill ist and then put all the stuff away again. No Problem but a hassle if the alternative would be changing AA batteries every few months. Though one thing possible would be to store low pressure from the small pumps over the course of a day and refill it just by solar with no batteries. Saaaadly the biggest consumer of electricity in the current setup are actually the selenoids. They are industrial 24V types and even though they are the smallest usual size they use 6W of power each. For comparison the Pump needs only 2W while operating the door like seen in the video. Thats the reason why i will soon kick them out and use a second pump, one for each side of the actuator. A Servo valve could be a solution though, It can be build relyable with common RC servos and a festo ball valve. But sadly its not that much of an advantage once i have to modify the thing anyways.

soldar:
Making the guillotine door reliable is very easy. Just use metal or plastic or whatever. If the coop is not too far from the house you can lead a nylon thread to your bedside and close the door manually before you go to sleep :)

You can install an IR CCTV security cam so you can see and count the chickens before closing the gate. :)

Calculating sunrise/sunset, altitude above horizon, etc is trivial for me knowing latitude and longitude but requires trig functions and you probably do not need such precision. Still an approximation is easy to implement and should be good enough. You can use only light but there is a small risk of it closing in the middle of the day if it gets very dark.

Doctorandus_P:
It looks like you're in a defending prosition and in a mood to reject any possible solution, instead of thinking a bit of how these general solutions can be used to fix your particular problem.

For example, the sunset / sunrize algorithm is easily found on the web.
If you're not content with a montly table for piece wise interpolation, use weekly piece wise interpolation.
If you don't want to use WiFi for problem identification, use a bloody blinking led if you're nearby.

Why would the guillotine door be prone to error? Yeah sure, if the mechanical part is executed poorly, (Wood that bends when it's wet etc), but when done properly it can easily be very reliable, and it is cheap to build. Problems with the string can also be compensated for in a multitude of ways. You can add an encoder to the motor, test wire tension or simply put the string in a loop so it can pull both ways.

If you're even a half decent engineer you can make a shaky bit of hardware work reliably with some inventive thought.

I'm glad for you your mechanical stuff works reliable, which is not much of a surprise when using industrial quaility air cylinders, but you probably had those lying around somewhere and they are probably too expensive to be a general solution for many other people.

Amper:
Hi!


My problem is very specific and i have put quite a lot of thinking into it. Im just not interested in solutions that will make the problem more difficult than it already is. So far it was literally a one day build with stuff i had laying around at my parents house. I like simple solutions much more than complicated mechanisms and tons of sensors just because its a simple problem that doesnt need them. Im Certainly able to do engineering better than you think i can, im in power electronics making kW sized bldc controllers, building small jet engines (not the tin can kind but actual working ones) and drones ("before it was cool" beginning in 2008 when there was no commertial parts availlable at all). Im very comfortable with both mechanical and electrical engineering but that doesnt mean that i like to over complicate things. The title of this thread ends on "(low power, simple)" and that is actually more difficult to achieve than you may think. I dont really see why i should start studying and statistically analyzing chicken behavior to train mm wave sensors, add wifi and webcams to close a stupid piece of wood that just needs to shut and open at two set times a day. If i wanted that i could just hang some raspberry with a webcan there, build an app and control it from the other side of the planet but thats just not what im looking for. The question also never was about mechanics so i just dont get why you had to start telling me how to fix something that is already working perfectly where id need to invest a day to rebuild the entire thing to get null benefit.

Sorry to be rude but actually it was a bit offending to be assumed some noob just becuase i dont like overcomplicated solutions for simple problems. Your solutions surely would work but they are obvious and not new to me. Im looking for something better than my current ideas that will not make the thing more complex to operate and maintain, wont need a mechanical rebuild and doesnt draw any power requiring external sources especially grid power and a working router nearby.
//endrant

@soldar
The Problem is that i cant fit a guillotine there, the large door to the outside in which the small is fitted is not something im allowed to hack up or bolt much things to. A Slider would need to go up to one meter where there is other stuff in the way and no wood to fit pulleys and motors. If i had built an entire coop from scratch i probably would have gone that way. Also its already the basement of our house, so if i were home i would not even need a string to operate it :D Its just reeeeeally comfortable to stay in bed in the morning and have it open without waking up in 5. Also as sad before, the initial reason to build it was absence of anyone for a few days at a time or when my mother has to work in winter and its already dark for a few hours before shes home.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod