Light sensitive/remote pet door battery powered

hi all

i have scoured the site but cant seem to find a project that i need, and would therefore benefit from any help and advice on how to build an light sensitive automatic door opener for our chicken coop.

it seems an obvious project to me,, hopefully one not too hard that i can do with your help.

we have a barn thats too far away from the electricity, so it needs to be self powered by battery.
i can look into trickle carging the battery by solar seperatley i am sure on the site.

but, the wife is sick of having to go each night and shut the chucks in to keep them safe from the fox, and then open up every morning.
we were wondering if we could use a standard light sensor you find on the cheap security lights at the DIY store, that would trigger some kind of motor or catch etc to slide or raise a door.
then if possible, to do the opposite when the morning comes.

if the LUX sensor is not possible, then maybe on a timer, or even posibly remote.

i need help and advice on the whole thing, as i have no idea on what type of mote, (if i need a motor at all) i need, will it burn out if it has power all the time?, how to stop it? loads of questions i cant even think of

support with your answer would be appreciated.

thanks in advance


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I have some useful info for ya! I've been working on this project for about a year and have some great people helping me. I'l be using a timer switch to open the door in the morning and again at night, this is much safer for the chickens. A light sensor might open the coop door to early in the morning whilst foxes are still around. Your chickens put themselves away at dusk, so you can set the timer to close the door after this time, the morning opening can be set for when it's daylight, but not too early. I'll be putting an instructable up when I'm finished, but I'll be using this http://www.reuk.co.uk/Convert-Digital-Mains-Timer-To-Low-Voltage.htm as a time switch coupled with a circuit diagram attached. The door opener mechanics will be a 12v geared motor spinning a length of 6mm threaded rod. The door will be attached to this via some tee nuts and will be slid open horizontally, then slid closed at night. If it works as planned, I'll put a full instructable up.
Goodhart7 years ago
First off:  we were wondering if we could use a standard light sensor you find on the cheap security lights at the DIY store, that would trigger some kind of motor or catch etc to slide or raise a door.
then if possible, to do the opposite when the morning comes.

if the LUX sensor is not possible, then maybe on a timer, or even posibly remote.



Yes any of those are "possible";  practical will depend on how heavy your doors are and how they open and close. 

I am not sure why you think the motors would be "powered on all the time"; as you can use the light sensors as switches, and then either a timer or other sensor to shut off the power once said doors are fully open or closed (if you supplied power to the motors continuously for any period of time past what is needed, you could indeed burn them out).  There are a number of ways to do this too, again, dependent on what you might need in your circumstance. 
 
another option for the motors would be actuators IF one can be found with a long enough carrying distance.
Deeder7 years ago
Okay i just quickly glanced through other comments and i have to say

Have you considered that using a motion sensor would be a bad idea?
Foxes are smart, and more importantly curious.  if they see their prey entering a doorway, even if it closes they will be tempted to go and sniff it

If the fox goes near the door, even to smell, teh door will open for it.



How about radio frequency tags that unlock on proximity, you'd have to buy them of course, unless you're very very very handy.



I cant offer advice, but me and my cousin were considering a cat-door but dont want strange animals wandering in the house.

And if foxes are a problem for you, dont use a light sensor- if it opens fora  chicken it'll open fora fox

please wont someone think of the chicks!
rockrat (author) 7 years ago
ok,

thanks for the replies so far everyone, i will try and answer the comments so far to help out.

Jayefuu -
Pretty much the chickens are in well before dark, i cant remember a time when they werent to be honest. I am happy enough to take the risk i think on that.

do i want it hardware or microcontroller?  errr... i daont know, hence asking for advice. i want the simplest easiest way, and easiest to build.

your idea of the counterbalanced door makes perect sense, i was thinling along the same lines as well, with maybe a pulley or something.

the door at the minute is a simple slide across a hole in the barn wall.
i was thinking of maybe using some drawer rails like you find on kitchen draws so it has a smooth action, and then could be mounted either vertical or hortizontal and moved via either a rod or cable.
This way, the door itself will be small and light. the hole is 8" x 8" square-ish.

in essence all i need is th block the hole and opene the hole,.
i have even thought of a hinged door that is raised by winding a peice of string on a motor that lifts the hinged door, then winding the other way  to lower it.

i think the bit i have more difficulty with is the "powering" it bit.

i.e what motors etc do i need?
how to i "ime" the motor so it runs for a set time etc?
how to i activate the motor, via the LUX (LDR) ?

i have no power, so what voltages?
where to get the bits (UK based)?

thanks all
Jayefuu rockrat7 years ago

do i want it hardware or microcontroller?  errr... i daont know, hence asking for advice. i want the simplest easiest way, and easiest to build.

Hmmmm..... I'm inclined to think that a microcontroller with minimal electronics linked to it might be best. It would be easier for people to troubleshoot your code from afar rather than a PCB or breadboard with hardware on it would be.

Options for starters with microcontrollers are:
Arduino: LOADS of documentation available online, development board with chip and bootlader for an Arduino Duemillanove are about £15-£20. It's a bit overkill for your project, as it can do a LOT. Programmed in C++
AVR: I've never used. A friend uses them, they're cheap, can be programmed in C, the ICs that you program with the dev board are easy to setup standalone on a piece of stripboard.
PIC: same as the AVR I think, but again.... never used one.


how to i activate the motor, via the LUX (LDR) ?

This link explains how to use an LDR in a voltage divider config. to produce a voltage that varies dependant upon the light available to the LDR. This voltage would be fed into the microcontroller. The Atmega chip on an arduino has a built in ADC (analogue to digital convertor) that will change the analogue voltage you put in to a value between 0 and 1023. You would then make a decision based on this value of whether the door should be open or closed.

where to get the bits (UK based)?

I got my arduino from ebay. You can get bits and bobs from Maplin on some high streets in the UK, though they're expensive and their staff often useless unless you know exactly what you want. Other websites for components are rs-online.com, farnell.co.uk, ebay.

I don't know how much you know of electronics or programming, so if I've been too vague I appologise, just ask if a quick google doesn't explain something I've said.
Jayefuu7 years ago
Here are some things for you to consider.....

1) The LUX sensor your refer to is called an LDR (light dependant resistor).

2) How will you know if your chickens are all inside when it gets dark? What if one decides she doesn't want to be inside when it gets dark, they will get locked out. Would it be a better idea to have you or your wife put them away each night, then it automatically releases them when it's light? That would at least cut your trips to the hen house down by half.

3) You would need to build a delay in for when it's light enough. Otherwise if it opens and closes each time it's light or dark, it could open up in the middle of the night when someone walks past with a torch, or if a car drives past etc etc etc. So for example.... if it's light, wait 5 minutes, if it's still light, it's probably day time not some muppet with a torch, so open the hatch. Same in reverse if a chicken poops on the sensor or it gets blocked by a leaf.... it would close down in the middle of the day. Oooops!

4) Do you want it to be fully hardware, or use a microcontroller of some kind? You could either make it entirely from discrete components (ICs and such), OR you could have a few components, connected to a microcontroller like an Arduino, PIC, AVR etc. At least then if you wanted to make changes it would be simpler than resoldering electronic components. It would depend on your previous electronics/programming experience which you choose.

5) With respect to the motor, you could use almost any small DC motor to open or close the door if you counterweight the door so all the motor does is provide the small amount of force needed to shift it one way or the other. Since the door and the counter weight would be well balanced, once moved up or down they'd stay that way until the motor span the other way.

6) What style of door does the coop have? Slid up, slide across...... ?