In or Out ?

Hi all,

I am after some advice, I have an arduino and some basic extras and I have really ignored it.

However I want to build something, but I am unsure if its possible or even how to!

I am disabled and we have a small dog, often I am unsure if he is out in the graden or indoors and so I have to get up and into my wheelchair as he just ignores my calls.

I was wondering if a project would be possible to tell me if he is in or out?

This could be as simple as a red and green LED and as he goes out of the door the red light is on so I know he is out and then when he comes back in the green light comes on.

We have a sliding patio door with a small step so something could be placed under the door so that it registers when he crosses over using maybe rfid or NFC??

Any ideas?

I think it is not easy beginner project, you should start binking LEDs etc. But it should be doable somehow. More than one sensor will be probably needed to know if the dog is leaving or coming in - imagine he come just over the sensor and than instead of leaving he changes his mind and returns home.

Possible for sure.
Detecting the dog passing through the door can be done in many ways - detecting in WHICH DIRECTION he's going is a much harder problem.

wvmarle:
Detecting the dog passing through the door can be done in many ways - detecting in WHICH DIRECTION he's going is a much harder problem.

You could mount two sensors in a row on the way out into the garden. And then whatever sensor alerts first will tell you in which direction the dog is moving.

Depending on the actual layout of your sliding door, this could actually be done simply with two motion sensors mounted to the wall next to your door. The disadvantage would be that they would alert to any object, dog or person.

Or maybe you could mount a third sensor about two or three feet high. That way, the system could distinguish between people walking upright and dogs.

carguy:
You could mount two sensors in a row on the way out into the garden. And then whatever sensor alerts first will tell you in which direction the dog is moving.

I suddenly picture a little dog standing in a doorway wagging its tail...

wvmarle:
I suddenly picture a little dog standing in a doorway wagging its tail...

LOL... well you could try to make the code so that it filters out inconclusive data... :smiley:

Maybe if one sensor lights up and the second one doesn't also within five seconds, discard your data and assume that nothing has happened. And place the two sensors on the bottom far enough apart that they can't be triggered simultaneously by a dog wagging its tail...

Combine some of the ideas presented here - one RFID reader outside, one inside to determine direction. RFID rules out triggering on short people, human legs, light sensitivity and, unfortunately, raccoons. Since they'll necessarily be rather close there may an issues with both readers signaling at the same time. Perhaps the readers could be detuned so their sensitivity is reduced to the point the tag cannot be read by both readers simultaneously.

.02

If the dog goes in our out through a catflap of the two-flap variety, it would be pretty straightforward to work out which one has opened most recently. You wouldn't even need an arduino.

I'm talking about ones with a big door with a hinge on one side, and set into that is a slightly smaller door with the hinge on the other side. They often have a light magnetic seal. All you'd need is a pair of contacts for the bigger door and another pair for the smaller. A latch circuit if some kind, and there you have it.

A purely mechanical solution might even be possible.

I have a cat flap
With 2 reed switches and a magnet which detects whether the cat has gone out or come in.
I had to use interrupts to capture the brief signal and some other stuff so I correctly detected the cats direction ( the door swings back and forth after it's operated firing both switches ).
So not really a beginners project , but there's a lot to be learnt with a book and the examples along the way .

( I did get it to "tweet" too , but that was a pain ).
As it's a Dog , could you not train her to operate a switch before she goes out and in ?

hammy:
As it's a Dog , could you not train her to operate a switch before she goes out and in ?

For any reliability that'd have to be a switch that the dog must operate before being able to go in or out, or the door won't open.

Thank you for the ideas

No he doesnt go through a flap, it is just a sliding door that is open all day when the weather permits.

I could place one sensor on the edge by the door and another further out so that it stos him just messing it up by peeking out.

With break beam sensors and some sensor logic you should be able to detect "just peaking out".

Two beams, beam 1 on the inside, beam to on the outside of the door frame.

Moving through (I assume body/head height - not leg height)
Break sensor 1, break sensor 2, some time both broken, then return sensor 1, return sensor 2.

Peeking out:
Break sensor 1, break sensor 2, some time both broken, then return sensor 2, return sensor 1.

The order in which the beams come back up tells you the direction the animal moves. Ignore any situation where just one beam breaks, have your sketch start paying attention only when both are actually broken.

This works as there is one and only one animal that can break the beams. You may want to add some user override button or so for when the wife is home and she walks in and out as well.

My choice is back with an RFID tag on his collar, and two readers (one inside, and one outside the door opening) - suitably separated to avoid cross triggering.

Slight overkill, but pretty reliable, weatherproof and proven tech.

Requires attention to detail of placement to ensure he’s within range as he passes the readers.