pet cat auto feeder

[Hobonschoice]

Hi All,
I am trying to figure out how to adjust my autocat feeder so that it will operate only for my cat and no strange manky black one that keeps stealing her food.

the device is left outside and i want it so that when she is within say 3 inches the drawer will open and when she leaves the drawer will close.

I have the device built completely and it has a simple switch at mo that when i push the button once, it opens and push it again it closes.

I am looking some ideas on how to ID proof it?

Thoughts so far are,

Some kind of reed switch on the front that is operated by a magnetic collar.
The problem with this i think is that the cat would have to be really close to trigger the reed and also might keep accidentally triggering it simply by shifting position.

or

Infra red device to an tag on a collar, I have no idea how to go about that but am sure that would give a good steady signal until she left the feeding area.

Please, please. give me some ideas how to do this? I have to go away for a few days next week and want to be able to leave food out for the cat!

thanks all
Dave

 

[flat5]

First thought: train the cat to operate a secret switch.

 

[crutschow]

Some type of RFID tag on the cat should work. You might start with hobbyist type devices such as at **broken link removed**.

But you probably couldn't get that going in a week.

 

[duffy]

RFID! RFID! Should be easy, they make an RFID cat-door, bet you could just mod one of those.

If not, I can recommend the Phidget RFID development kit. It was cheap, came with a bunch of different tags (including a couple that even LOOK like collar tags) and runs completely off a USB port.

Yes, you would have to commit an old computer to the project - but that will make it easier to develope a cat-feeding algorithm that is purrfect!


Jesus, did I really just type "purrfect"? I suck. What happened? I was cool once, I swear.

 

[Mike_2545]

I see you can get RFID readers that are serial. Connect to micro-controller and have a stand alone unit!

 

[duffy]

Get a cat that's radioactive! Then put a geiger-counter on the food dish.

 

[user_88]

Most cats do not like collars at all ..... completely different from dogs....
Do they make subcutaneous injectable RFID tags? ..... Probably check with your vet for medical aspects.

 

[Mike_2545]

They do but they are awfully small and you need to run the scanner tight to the skin to get a reading. So basically you have to cat scan the poor critter.

Wow that was bad, even for me...

 

[duffy]

Most cats do not like collars at all ..... completely different from dogs....
Do they make subcutaneous injectable RFID tags? ..... Probably check with your vet for medical aspects.

Yes, as a matter of fact that kit I referenced INCLUDES one.

They don't give you the injector, though. Darn.

 

[flat5]

If the cat has to move through a tunnel to get to the door then he/she will be close to the reader.

 

[Hobonschoice]

I was sort of thinking along those lines as well, maybe create a forced situation where she would have to postion her collar somewhere near the reed relay, i was just googling cat flaps and the electromagnetic one i found shows a distance of 1.5 inches to operate the reed. Thats not bad.
Problem i forsee with this is that i canmake her open the box but how do i close it? The reed would have to be activated on departure as well.

That is also the problem i have with training the cat to operate a button, fine she'll do it to open the box but very unlikley she'll be bothered to push it again to close it.
I realise i am talking about incorporating a tier somehow but then it's going beyond my electronics skills i think.

just to clarify. The switch i have at present works like this.
Open and close the contact, door opens,
open and close contact again, door closes. Like a CD drawer

any more ideas anyone?

 

[Hobonschoice]

should read timer not tier.

 

[crutschow]

You could use a timer to keep the door open for a period of time (say 5-10 minutes) after it's triggered and then have it close the door after time-out. The ubiquitous 555 (or 555CN for lower power) timer connected as a one-shot should work. It's fairly simple to hook up. You can Google "555 timer" for all kinds of design info on how to do it.

 

[Hobonschoice]

ah , right, now i stumbled across this 555 thing yesterday but wasn't sure how it would work.
So,
My circuit is 12vDC mains transformer, i would , at a later date replace this power supply with a battery.

The on off/ open close mechanism is an old CD drive.

Now i have two naked wires coming from the open close button,
when i make a contact, nothing happens until i release it again, so it's whatever that switch is called, lol, the same thing again, when i touch and release the wires again the drawer closes.
So would the 555CN do this job and would it be ok on 12vdc?
I was looking at time delay relays but hardly any in the 12v range and veryexpensive for something i'm not sure would work.
Thanks
Feel like i'm geting closer to the solution.

 

[ericgibbs]

ah , right, now i stumbled across this 555 thing yesterday but wasn't sure how it would work.
So,
My circuit is 12vDC mains transformer, i would , at a later date replace this power supply with a battery.

So would the 555CN do this job and would it be ok on 12vdc?
I was looking at time delay relays but hardly any in the 12v range and veryexpensive for something i'm not sure would work.

hi,
Ref the 555 timer , look at this link.


also
**broken link removed** for ideas.

The 12V transformer will have to be type that outputs 12V dc, I would suggest at 1amp. Many wall wart are available that do just that.

The 555 will work on 12Vdc.

How big is the cat across its biggest diameter.?

 

[Hobonschoice]

OK, tried to read those intro's on the 555 and the Lm555, i am getting the idea that they need two switch's, 1 as a trigger and 1 as a reset? is that correct?

 

[ericgibbs]

OK, tried to read those intro's on the 555 and the Lm555, i am getting the idea that they need two switch's, 1 as a trigger and 1 as a reset? is that correct?

hi,
An option is a 555 monostable, set for 5 mins.

Cat triggers 555, flap opens for 5 mins then closes.

How do you plan to detect the cat wants food.??

 

[Hobonschoice]

Right then guys,
This looks like the jobby.
Adjustable 1-10 Minute Timer Project

only question i have is will this reset itself after timed out?.

So cat approaches feeder,
activates reed relay which triggers the 555 and 10 min timer , Food Door opens
cat stays for 5 mins and wanders off,
reed re opens breaking circuit to 555

If the door closing is dependent on the 555 finishing its countdown, will the sudden departure of the cat and the reed being suddenly open deprive the 555 of power and stop the countdown or does it countdown without power because of the capacitor.

Sorry if i am sounding dumb but i really am a novice to this sort of thing.
learning as i go along really

 

[Hobonschoice]

sorry didn't see you last quetion,
i was thinking of having a magnetic collar on the cat which will trigger a reed relay when within 3 inches of the feeder. That reed would trigger any 555 circuit.

 

[ericgibbs]

sorry didn't see you last quetion,
i was thinking of having a magnetic collar on the cat which will trigger a reed relay when within 3 inches of the feeder. That reed would trigger any 555 circuit.

hi,
The 'flap' how do see this arranged and what drives the flap.?