PET DOOR auto-gatekeeper

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errow000
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PET DOOR auto-gatekeeper

Post by errow000 »

Hi I have a cat that goes out but i only want him to go out in the morning and only in the morning, so i want to get a pet door that will allow me to:
let him go out at 5am (without waking me but after he exits the door will then switch modes to only allow him in but not back out, until 5am the next morning. <p> I mean its ok that the door will stay on "in only" mode till the next day cuz other anmals entering is not a probelm here.<p> It is necessary to be like this cuz i am not home by the time he comes around to come back in so this way he gets his outdoor time till like 9am or 10 am then comes in and he can stay in the rest of the day.<p>here is what i have figured out so far:
none of the electrc pet doors will work for me, and he doesnt wear a collar anyway.<p> I will have to modify one of the 4way locking manual switching pet doors to accomplish this.
like this one:
the "ideal pet" and "staywell 300series" would work
http://www.doors4pets.com/Pet-Doors/cat-flaps.asp<p>
here is a schematic:
http://www.catflaps.com/exp_300.htm<p>so i dont know anything about building a gadget to do this but i do have a vision:
it would need a digital timer connected to a couple of sesors or switches one on either side of the flap, the outside switch/sensor when triped would tell it that the cat went out causing the gadget to switch the knob to "in only mode" than when the insisde switch/sensor is activated by the flap pushing in, the gadget would just reset to turn the knob to "open" at 5am the next morning.<p> I dont know much about building this kind of thing but it doesnt sound like someting very difficult to accomplish, if i am wrong let me know.<p>so if anyone has any guiadance for me as to where to begin and or specific materials anyone can tell me i need please let me know.<p> thank you all
errow000
Dean Huster
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Re: PET DOOR auto-gatekeeper

Post by Dean Huster »

If the cat's obviously old enough to go out on dates by him/herself, why the importance of the curfew? Or is it a weather thing?<p>Dean
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

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Engineer1138
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Re: PET DOOR auto-gatekeeper

Post by Engineer1138 »

The simplest thing, if you can guarantee that the cat will be out by 9 am, is to make the door "in-only" at that time with a timer. So as far as Kitty goes: you snooze, you lose!<p>The alternatives are more complex:
say you have a mechanism to let the cat only go out once per day that works by detecting the door opening. Now the cat pushes the door open, starts to go out then notices it's raining and comes back in (my dog is famous for this). If he then wants to try again, he can't!<p>So to get around this you need stateful behavior:
0) Door closed, set to "exit only", cat inside.
1) Cat pushes door open.
2) Cat's weight is detected on outside doormat while door is partially open.
3) Cat's weight is detected on outside doormat while door is closed.
4) Door now set to "enter only"<p>If this sequence is not observed, you can't guarantee that the cat made it all the way outside. Seems like an awful lot of work for a cat door.<p>Intuitively, it seems like the simplest solution would be mechanical: some sort of rachet that prevents the door swinging out which is only triggered when it's opened.
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Re: PET DOOR auto-gatekeeper

Post by Ron H »

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Dean Huster:
If the cat's obviously old enough to go out on dates by him/herself, why the importance of the curfew? Or is it a weather thing?<p>Dean<hr></blockquote>
He'll want the cat to stay out of my yard during my waking hours, or he may never see his beloved pet again. I'm fed up with cats crapping in my yard. The older I get, the crankier I get.
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haklesup
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Re: PET DOOR auto-gatekeeper

Post by haklesup »

Your idea has several parts to it.<p>1. Electromechanical actuator to move the locking knob to the correct positions or replace such a mechanism.<p>2. Apparatus to sense the "last use direction" of the door.<p>3. Logic and driver circuitry to recieve the sensor input and drive the actuator.<p>
For 1 you need to devise a way to turn the knob where you want it to be. This looks a little tricky so I might approach it by removing the stock lock (or buy a non locking cat door) and position 2 solenoids to prevent the door from opening in either direction (you decide if it is unlocked when on or off). Now your curcuit only needs to provide two outputs to drive each solenoid seperately when needed. Another solution might use a rotating RC servo from a toy to move the locking knob.<p>For 2, A PIR dectector would be easy to get and adapt to send a signal that says something just passed. Alternatively, a couple of leaf switches mounted to sense the door movement would also work and be less expensive.<p>Finally the circuit. You could probably be able to create a circuit using a variety of flip flops, timers and counters but since you want it to be keyed to the time of day, you will need a real time clock somewhere in there. A PIC (like the basic stamp) seems like a reasonable solution here because you can implement the clock, recieve signals from a few sensors and drive two or more outputs all while being able to reprogram on the fly without rewiring anything.<p>I recently installed a passive cat door but my dog decided it wasn't big enough and tried to widen the hole (bad dog). All fixed now and she knows better now (can't chew through stucco).
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jwax
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Re: PET DOOR auto-gatekeeper

Post by jwax »

I'm with RonH!
We've got too many mangy strays- trash can digging, flea-infested, alley types that make for fine target practice. I can't imagine anybody sending their house pet out to mingle with the vermin. Nice if your neighborhood is free of the alley cats.
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grant fair
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Re: PET DOOR auto-gatekeeper

Post by grant fair »

Long ago I lived with a lady who had two cats, and when winter arrived I realized a lot of heat was escaping through an open window in the cellar, into the Canadian winter. So I set about designing a cat door.<p>I got a washing machine solenoid and fastened it to a rigid wire which went to a little door on a hinge, fastened to a piece of plywod I had filled the window in with. The door was held shut with a homemade magnet latch. I had some 30 thou PCB which was flexible enough to make two large pressure switches with - cat steps on switch, each piece of copper clad PCB touches the other and switch closes. This fired a low voltage DC relay which fired the 110 volt washing machine relay. With a resounding WHACK!!! the door opened and stayed that way as long as the cat was on either, or both, switches. At least that was the plan.<p>So I picked up the larger of the two cats, a confident male who loved to wander and hunt, and put him on the switch plate. WHACK!! The cat howled and took off at high speed, and not out the door. I tried a few times more (just enough to classically condition the cat, I later concluded) and thought it was back to the drawing board.<p>The next design used an small electric motor running a belt onto a big pulley. It was very smooth - and very quiet. It used some op-amp comparators so that when the door was open, if the cat was on the switch, and the mercury switch on the top of the door was closed, the door hunted back and forth slightly in the wide open position. No cat, and the door closed and latched magnetically. No loud sounds. I thought it would be a winner.<p>I got the cat again and put him on the switchpad. The motor silently began, and the there was a very slight click as the magnet latch let go. Hardly any noise at all. But the cat, no doubt expecting a loud WHACK! screeched, and took off again at high speed, and not through the door.<p>So we bought a commercial cat door.<p>Grant
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Chris Smith
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Re: PET DOOR auto-gatekeeper

Post by Chris Smith »

If the cat goes out and a Racoon comes in, your stuck with a new pet!<p> And your pet is stuck out side and cant help you round up the critter in your house.
bridgen
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Re: PET DOOR auto-gatekeeper

Post by bridgen »

You could get a dog and train him as a doorman/bouncer for a conventional cat flap and to police the mog's movements.
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Re: PET DOOR auto-gatekeeper

Post by bodgy »

Actually I've been mulling over a similar problem, mines is to just let my cats in and out and not the neighbourhood strays.<p>1. Timer - easy the timer on my webpage would do that part.<p>2. My cats only - researching cheapish RFID kits<p>3. Flap activation - here I think a DIY effort would be in order, instead of the cat flap opening up, cut a flap that is two way hinged and opens like a door. Then it is easy to use a common or garden door solenoid, either the after market type for cars or if Maplin still sell them security door solenoids.<p>Colin
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Engineer1138
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Re: PET DOOR auto-gatekeeper

Post by Engineer1138 »

Grant: Did you post this to sci.electronics or comp.robotics.misc a long time ago? I have saved a hilarious post from circa 1997 that's very similar to this.<p>
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Grant Fair:
Long ago I lived with a lady who had two cats, and when winter arrived I realized a lot of heat was escaping through an open window in the cellar, into the Canadian winter. So I set about designing a cat door.<p>I got a washing machine solenoid and fastened it to a rigid wire which went to a little door on a hinge, fastened to a piece of plywod I had filled the window in with. The door was held shut with a homemade magnet latch. I had some 30 thou PCB which was flexible enough to make two large pressure switches with - cat steps on switch, each piece of copper clad PCB touches the other and switch closes. This fired a low voltage DC relay which fired the 110 volt washing machine relay. With a resounding WHACK!!! the door opened and stayed that way as long as the cat was on either, or both, switches. At least that was the plan.<p>So I picked up the larger of the two cats, a confident male who loved to wander and hunt, and put him on the switch plate. WHACK!! The cat howled and took off at high speed, and not out the door. I tried a few times more (just enough to classically condition the cat, I later concluded) and thought it was back to the drawing board.<p>The next design used an small electric motor running a belt onto a big pulley. It was very smooth - and very quiet. It used some op-amp comparators so that when the door was open, if the cat was on the switch, and the mercury switch on the top of the door was closed, the door hunted back and forth slightly in the wide open position. No cat, and the door closed and latched magnetically. No loud sounds. I thought it would be a winner.<p>I got the cat again and put him on the switchpad. The motor silently began, and the there was a very slight click as the magnet latch let go. Hardly any noise at all. But the cat, no doubt expecting a loud WHACK! screeched, and took off again at high speed, and not through the door.<p>So we bought a commercial cat door.<p>Grant<hr></blockquote>
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MrAl
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Re: PET DOOR auto-gatekeeper

Post by MrAl »

Hi there,<p>I'd hate to be that poor kitty if one rainy
morning something went wrong with the latching
mechanism and i couldnt get back in.<p>Please give some thought as to what can go wrong
once the thing is built and (?) tested.<p>On behalf of your kitty, i thank you :-)<p>Take care,
Al
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jollyrgr
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Re: PET DOOR auto-gatekeeper

Post by jollyrgr »

Hopefully I read this right and understand the problem correctly.<p>1. You want to let the cat out at 5:00AM or some time there about.
2. You want the cat to come in at any time it wants to.
3. Any time between lets say 6:00AM the same day and until 5:00AM the next morning, kitty cannot get out on his own.<p>This is easy and can be acomplished with an off the shelf timer, solenoid, and the cat door you mentioned or similar door. <p>Since you are not worried about other animals coming in, there is no need to "password protect" to just your cat. Nor is there any need to detect the cat being present. All you need to do is fix the door such that it stops the cat from going out except for a pre-determined amount of time around 5:00AM.<p>Get a standard light/appliance timer that you can pick up for a couple bucks at any department or hardware store. Alternately you might want to use a digital timer which will cost you a bit more. Cats are fairly predictable but I doubt most will recognize 5:00AM or even 5:15AM as being different. You might want to consider letting the cat roam at will in and out for about an hour or so around 5:00AM. So most cheap mechanical timers will allow you to set on ON time and OFF time one hour later. <p>The digital type are nice as these do not need to be reset after a power failure. You mentioned using one and it will work just fine but is probably overkill.<p>Run a solenoid off a DC power supply/wall wart connected to the timer. Rig it such that when the solenoid is energized and pulls in it allows the door to swing in and out for the hour or so that you will allow the cat to leave. Does it really matter if the cat goes out at 5:00AM then comes back in at 5:15 and leaves again at 5:20AM? For that matter what would be the problem of leaving the door free both ways until lockdown time? When the solenoid is de-energized have it rigged so the door cannot swing out but can swing in. Thus you don't want it to latch the door, just stop it from allowing the cat out. Sort of a check valve if you will.<p>I cannot tell from the picture of the link you posted exactly how the door locks. I guess you could rig a solenoid to activate this door latch as needed.<p>But if you pick a fairly simple "solid" swinging pet door, and not a flap, you can easily rig a solenoid to stop it from swinging out. You simply block the door from swinging out with the piston of a solenoid. Go here and see solenoid 04N019 as an example:<p>http://www.alltronics.com/relays.htm<p>This solenoid works on 12 volts and has a one inch throw. If you fastened it to the side of the pet door and placed it so that it just cleared the swinging door while energized but while de-energized it would stop the door from swinging out. The bottom, middle of the pet door would probably be better but you could experiment and see. I only give this solenoid as a suggestion and you can use anything you have on hand. Just be sure it is rated for CONSTANT DUTY.<p>Run the wires to the power supply and timer. I strongly suggest that you use the low voltage wire along as much of the run as possible.<p>As far as my design is setup, it is "fail safe". The cat can always get in to safety but can only get out for a short time. No automatic swinging doors or things that can trap and hurt the cat. Just a one way valve for 23 hours a day. You might even place an LED on the inside of the door that shows the relay is energized. Thus the cat will learn when the door is unlocked when the light was on.
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grant fair
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Re: PET DOOR auto-gatekeeper

Post by grant fair »

Hey Engineer1138-<p>It is possible that I posted about this previously, but I don't recall - but my memory is not that good.<p>If you send me the post I could tell you if I wrote it. Im grant.fair[AT]sympatico.ca<p>Grant
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MyPugsABrat
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Re: PET DOOR auto-gatekeeper

Post by MyPugsABrat »

My two cents.... Purchase one of those electronic activated pet doors, and one of those security outlets that you can plug lamps etc into that turn your appliance on and off with a timer. The outlet timers usually sell for less than ten bucks. Plug the electronic pet door (make sure it locks when the power is off) into the timer. Set the timer to shut off at 10 AM or whatever time you need the door to lock. Set the timer to go on again when you want your cat to be able to go back out and party again. That should permit you to do exactly what you need.
But... you'll need to put a collar on your curtain climber for the pet door to work.
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