Hi everyone,

I'm new to this forum. I think that somebody here must know what I need to do for my project.

I have built a cat wall for my 2 maine coon cats. It has 6 different habitats in it. I never know which habit my cats are in. I've attached a pic of one of the habitats; they are all similar. It is carpeted so my furry friends are comfy and they often sleep in them.

I'm close to completing the project. This is in my theatre / entertainment area.

What I hope to do, with the most conservative spend that I can get away with is have a visible light(s) mounted that could do any one of the three things listed below, in order of preference:
A) a single LED light that will shine red if the habitat is occupied and green if it is not.
B) Two LED lights, one red, one green. The red would be on if occupied and the green if it is not.
C) One LED light that simply turns on when the habitat is occupied

These habitats have about 1' square of carpeting on the bottom held on with adhesive that i could slip some sort of small pressure or weight sensor underneath.

It is built on a false wall and the adjoining room is a utility room that is simply framed in, so I can easily run any necessary wires behind the wall and drill a small hole through.

I did do an LED light project that for a newbie like me was really easy and I was hoping this wouldn't be alot more complicated than that. I bought a controller and a string of lights and the controller gave Alexa the ability to turn the led strip on or not. I no longer think it's quite as simple and there probably isn't a packaged solution available for it, but I just can't see it being incredibly complex or expensive.

Do you have any advice or could you point me in the right direction so I can try to figure out a solution please?

Thank-you all for your assistance !

James

 

The basic concept is pretty simple. The easiest display will be for an LED that is on if the habitat is occupied and off if it is not (your choice C). The additional complexity for the other two is pretty minimal.

A very simple weight sensor would be to drill a hole in the center of the floor underneath each carpeted area and put a bit of easily compressible foam under the carpet. Then put a reed or lever switch up into the hole such that it is not activated when there is no weight on the carpet and is activated if there is more than a certain amount of weight (in the center) present).

But there are some devils in the details. It has to be set for the lightest cat and if you end up getting a lighter cat (or the one you have loses weight), the system might stop working.

It also relies on there being enough weight in the center of the carpet to depress it sufficiently no matter where the cat happens to be located in the habitat, including laying across the opening with part of its body out.

What about other things that might end up in the habitat? Can the cats take toys in there that they leave behind? Then you have to worry about the heaviest toy left in the center of the carpet being enough to activate the switch when it is set so that the lightest cat lying part way out of the opening will also activate it.

There are ways to address some of these, but with pros and cons. One alternative would be to mount the carpet on a thin board (like paneling) and support this on the bottom of the habitat with a stick on one side and foam on the other so that when any object is in the habitat it will compress the side with the foam no matter where it is located. You still have the light cat on the side with the stick versus the heavy toy on the side with the foam issue, but it probably not as severe.

Another way is to put in IR (infrared) emitters and detectors in each habitat that detect the beam between them being broken. Depending on how much space there is relative to the smallest cat, you might need multiple detectors in each habitat to before that at least one beam is blocked by the cat no matter where it is. But this approach is likely more susceptible to sensing a toy left in the habitat unless you can mount them high enough that a cat is guaranteed to block it but a toy is not (this might be easier said than done).

Lots of other ways to come at it, each of which is going to have its pros and cons. Things to consider are how critical is it that the indications always be correct and how much are you willing to spend to achieve a high degree of correctness?

 

Excellent, thanks. All good points and questions ! As Maine Coons, they are the largest domestic cat breed, but they take 5 years to grow to full size. My male Yogi is 1 years old and only 12 pounds, the my female BooBoo is 3 years old and only 18 pounds. Yogi will grow to about 30 pounds. BooBoo will cap out around 20 pounds as females are smaller. I'm not worried about them bringing toys in, because it's all vertical, it means they have to navigate up a series of steps and rope bridges etc to get there and their cat toys are only a few ounces at the max. I'm totally fine with doing the single LED solution. It's more of a project from the heart that I've worked on for many months and for the cool factor; false positives are not the end of the world . People ask me why ... I explain that since I got my divorce, I now get a lot of tail. Because between the two cats, they have 37 inches of tail and I'm forever stepping on them, I wanted to give them a safe haven and something cool and unique in my home

 

I'd try the reed switch approach first. All you need for each habitat is a switch, the LED, and an appropriate current limiting resistor (plus the wire to hook them up). If you use a 5 V wallwart (or pull the 5 V from a cheap USB charger), then you can figure that each LED will have about 2 V across it when on (depends on the color) and what you probably want for this application would be the cheap LED indicator lamps that typically draw want about 10 mA of current. So you would need a resistor that drops the remaining 3 V at a current of 10 mA, which equates to a 300 Ω resistor. This is a standard value, but either 270 Ω or 330 Ω are more common and either should work.

I'd probably have more confidence in the board supported by the stick on one side and foam on the other.

To support the two LED solution, you would just need to get SPDT switches and the two LEDs can share the same resistor since only one will be on at a time. Depending on what type of bicolor LED you get, that might work for it, too, but it might not.

 

Certainly a 12 pound cat is heavy enough to compress a foam spring or a small coil spring a bit. The carpet square will need to sit on a platform with a hing on one edge and a thin foam spring on the opposite edge and a contact pair someplace in between. The hings can be just a strip of better duct tape, half on the platform and half on the habitat floor. The floor contact could be a brass thumb tack. Really, a pair of contacts would be even better, then both wires can be not moving. The contact on the platform could be a square of copper foil or brass screen, some material that does not corrode and develop an insulation layer. The bit of foam will compress and allow the switch to close. That is as simple and cheap as I can make it. The contact on the bottom of the platform could be a copper penny if nothing else can be found. Or two of them with a wire soldered in between.

No great amount of electronics or great expenses. The platform could be a square of wood paneling or a piece of formic or even apiece of metal cut from the enclosure of a scrapped microwave oven. It only needs to be stiff enough to open the switch when there is nobody home and close when there is.