I’ve seen a couple of questions about this already but none were asking a question i need an answer to, some asked about timed pet doors and light sensors of sorts. I don’t have much experience with arduino, and have never built a fully functional project but this seemed interesting. I have a normal pet door and would like it to simply open when the pet is at a certain distance (and then obviously close after the pet is out), is a simple motion sensor the best choice or could an ultrasound sensor work better? I ask about the ultrasound sensor (maybe with this sensor i can control the distance at which the object needs to be at for the door to open?) because it’s one of the only sensors i’ve ever used (I took a part of a course for arduino). My idea would be to put two sensors, one indoors and one outdoors, when the first sensor is activated the door opens, waits 5/10 seconds and then closes, the second sensor would work the same. Is there a better way to do it? What sensor would you recommend? Do you have any general advice for building the hardware? These might be a stupid questions, I don’t really know what i’m doing but that’s the whole reason i’m asking.
We used to have a cat and had a cat flap that could read her microchip. When the microchip was detected, a small catch was released and she simply pushed the flap just like any other cat flap.
Motion sensors (PIR or ultrasonic) just tell you that something moved within their field of view. They don't tell you what it was that moved or recognise a specific object - in this case the cat.
A cat's hearing extends beyond that of us humans so it might not like ultrasonic sound.
Are you hoping to detect/recognise a specific cat?
It's not clear from your description whether you would like your door to simply unlatch, allowing the cat to push it open, or whether you are looking for a motorised door that opens and closes.
Motorised doors will have added complexity - they need some sort of mechanism that can open them (likely both ways) as well as other sensors to detect if the door has jammed or whether there is an object in the way when they are moving.
It is up to you to do all the structural building and also powering your project. Such things are not something you can go out an buy or you would have one by now.
First of all thank you so much for the response. So my cat is, apparently, too lazy to push the door open (the door already opens freely) so i will be designing a motorized door, i already have a couple of motors and sensors from a kit, i was thinking of using the ultrasound sensor indoors and the motion sensor outside (since i only have one of each and those who responded to my question said ether is fine). I would rather avoid putting a chip on my cat as a collar is uncomfortable, it doesn’t matter if it opens with other objects, the door opens to the balcony so im not worried about intruders. For the mechanism i was thinking of using a string attached both to the motor and the door. This doesn’t have to be amazing quality, as long as it works most of the time it’s ok, meaning I don’t think i’ll add a way for it to fix itself if it gets jammed, mainly because that sounds too complex for my skill set and because i’m sure i would have to buy more supplies. Thank you so much again for responding.
So what does it do when it wants to go out, just stand in front of the door?
At the moment the door is propped open so that she can go in and out when she wants, but it’s getting cold now so designing the motorized door will keep the cold out, hopefully
Let's get the motorized door working first and then think about controlling it!
Your cat is lazy but not stupid.
What if it doesn't want to go out but instead just sits in range of the sensor or walks past.?
I will get right on that, i think i’ll have some time tonight and tomorrow to actually try to build this thing
Of course not, my cat is far from stupid, just a little spoiled
The door that brings to the balcony is in a part of the kitchen the cat never goes to unless she wants to go outside, thx for the question though, I hadn’t really thought of that
It is why some will use flowcharts.