I am a programmer by trade, but have little to no experience with engineering. That being said, I know roughly what I would need for my project, but have no idea what the actual names would be, or how/where to find them, etc. I would love some advice!
Long story short:
My dog loves to go after my cat's litter. My plan is to attach a door to the opening of her litter box (its an enclosed top) that's connected to a gear. Its default position would be fully raised. I would like some sort of proximity sensor; not just an IR motion detector or anything, but perhaps some sort of [long] range NFC, or [short] range bluetooth item that is small and battery powered. The idea being, this little device has a range of ~3 feet. I have a sensor on the door, which if it detects this other sensor within 3ft, the gear closes the door over so there is no entry to the litter box. This small sensor would be attached to our dogs collar when we are not home and he may try to sneak in there.
Reasonably simple idea, but I'm not sure where to start with finding either a ~3ft proximity sensor not based on just motion, or something of the like.
I've never used Arduino at all, so im sure I would have more questions - but I would love some advice on the feasibility of this, and the names/links or any other information on the parts you'd expect would be most suitable for what I want to do.
My first thought was RFID but it sounds like that might get tricky/expensive for your desired range. One thing you have to consider is what happens if the cat is using the box when the door is triggered. The resultant trauma could cause kitty to eschew use of the box, certainly not a desirable outcome so you may want to add an occupancy sensor and only close the door when the box is unoccupied.
Have you already looked at RFID tags? A problem may be the often short range of such systems.
In the simplest case only a cat tag would open the door, when the cat is close enough to it. Then the cat may get frightened by the suddenly opening door. OTOH cats are used to pass through cat flaps, which they open themselves. In this case the flap can be locked and unlocked, so that it does not move by itself. I'd think that such systems are readily available, for locking out other animals.
Other (DIY) tags look much more problematic to me, e.g. due to the size and weight of a controller board and battery for an active tag.
Just noticed that Robin2 thinks the same about the door mechanism. Do some research in that direction, before thinking about locking such a door, perhaps you find approved and already available solutions. Good luck
Previously I'd toyed with the idea of a exterior cat door operated by a signal in the cat's collar. I even searched the internet for ideas and not surprisingly there are many projects just like this! Just search for 'arduino cat door' and prepare to be swamped by instructables. Of course, feel free to create your own solution too -- that is part of the fun of arduino.
so. let me understand.....
you have a place in your house in which the cat leaves 'doggie treats'
the dog wants them
the cat is fine with the dog having them, well actually, when I asked my cat if he minded that our dog goes into the cat litter to get the doggie treats, the cat looked at me with disdain then looked off in the distance with an air of aloofness. I just took that as if he could care less.
ok, back to the wheels of the universe that you put in motion....
you have to go into the cat litter and since you are not wanting your dog to have those particular doggie treats, take them with some daily routine and seal them away from the dog.
and, if you love your dog half as much as I love mine, You go out to the store and pick up bags of 'doggie treats' in which you bring home, then offer to your dog.
I chose a different route. I buy better quality cat food, knowing that I get a two-for-one deal.
thinking about your goal...
you can have a half circle that is fixed on the litter box.
and a second half circle that you spin to put in place.
have it covered all the time, that is until the cal comes near it, at which time it rotates and opens.
or have it open until the dog comes near.
if you give them both a bath, and leave the collars off, the cat is prevented from it's goal, same as the dog.
or, the dog has access for that day.
dog proximity seems more advantageous to your living space.
but, there is the off chance that the dog will hang out nearby, dogs love to lay down anywhere.
and having a cat access chip would also help in your quest.
a simple servo motor could lift the door, or spin it, or whatever.
power supply is easy enough.
RFID chips and antenna
any style UNO/NANO/mini, would work.
