[jonaswi]

I live in an apartment with quite strict fire-protection standards. Due to the fact that I have a cat that absolutly loves to go outside, I needed to find a solution for him to get outside without a catdoor trough my door.

So I installed a fire-protecion-approved door drive that is hooked to a raspberry pi. Another raspberry pi then analyzes a video stream and detects my cat. If my cat is in the frame for n amount of time, a message is sent to the pi conntected to the door drive and the door opens up slightly for him to get in.

[dscpls]

Wow. I literally just sat down to relax after building a cardboard prototype cat door fitting in my open window in winter. You just made me feel partly inferior, and partly like I'm in good company

[ceejayoz]

Now check out this project: https://www.youtube.com/watch?v=1A-Nf3QIJjM

A cat door that can tell if the cat has a mouse it's going to "gift" to you, and locks to keep the cat out.

[mavsman]

I may now get a cat just to set this up.

[knz]

Sounds like there is a market for fire standard approved cat doors! ;)

I loved reading what you are doing with the Pi though.

[jonaswi]

As you might have guessed, that came to my mind too. Due to the fact that I have worked with a company in the fire damper business, I was contacting them and we were brainstorming about it. The thing is: The market is just non existent. Also fire-protection regulations can be very specific depending on the country you are in. For example, EU ratings are not always recognized here in Switzerland.

Since last week I'm in contact with the manufacturer of the door drive tough because they maybe want to create a product out of it. To be honest I think it would pure marketing and at the moment it is very unlikely to ever hit the market.

[darkmighty]

A fun dream I've had (context: I've always been confined to apartments) is some sort of cat/pet utopia in a block, so they wouldn't be stuck inside alone. But that wouldn't be feasible since they have to navigate the fire-proof doors between floors...

Unless your cat door goes to market. May luck be on your side :)

(really, don't underestimate niches, you can probably find plenty of places to sell this sort of product...)

[leetbulb]

Do you have a link to the "door drive" that you're using? I've had this idea for a long time and really want to build it.

[jonaswi]

I don't use this specific drive due to the fact that another company gave me a better deal for some marketing. But if I had to choose again, I would buy a dormakaba ED 100 or ED 250 (depending on the weight of your door). They support multiple opening angles depending on how you activate it.

[lostlogin]

Does this open a door or a cat door? I’m just imagining breaking into places by wondering around holding a picture of a cat.

[bborud]

Do you have a screengrab of your cat?

[jonaswi]

Here is a picture of him examining the tech behind his magic door https://i.imgur.com/81VgqaR.png

[bborud]

Now here's an experiment: can you trigger your door by printing out an image of your cat? :-)

[paines]

super cool! Sorry for my ignorance, but how does it close again? Do you issue fire alarm and it closes ?

[jonaswi]

The door stays open for n amount of time (normally around 1min but I changed it to 30sec). The drive has a laser sensor attached to it (it is required to have installed with automatic doors in Switzerland if you don't want any issue with insurance). As soon as the specified amount of time has passed, the door drive tries to close the door. It only works if the laser sensor detects no obstacles.

Maybe a bit off-topic but: The only thing that differs an "fire-protection approved" door drive from a non approved drive is that the drive is not allowed to have an option to keep the door open. Also in case of power outage (or fire) the door needs to close without power.

[stephenwithav]

Can you please open-source this?

[subleq]

Why do you use two separate pis for it?

[yellowapple]

I'd imagine the processing power required to detect whether or not a video feed contains a cat doesn't jive well with sharing a CPU with something presumably-realtime-sensitive like driving a motor to open a door.

[jonaswi]

You are exactly right. Before I "optimised" the image recognition the whole detection part was running on a Mac Mini. I also like to "separate concerns". The Pi that is handling the door opening runs Alpine with a read-only file system so whenever there is a power outage or whatever it boots into a known good state. The image processing part is behind a big UPS and is running with a writable file system.

[nicoburns]

Seems like the door opening Pi would be a good candidate for an esp8266 or an esp32 (if you were looking to save costs and/or have fun playing with a more limited environment)

[bigiain]

esp8266 means wifi, and also means you don't have the whole linux TLS ecosystem to play with. I'd be somewhat cautious about using an esp8266 (as much as I like them) to unlock my front door...

[penagwin]

Why would you be cautious? Not saying there's no downsides, but if anything I consider it to be an "upside" that the device is simpler. Now I don't need to worry about linux, or making sure it's a read only filesystem with an image all setup, etc.

I look at it this way: If you want a remote device that measures or controls just one or two things, but does very little if any calculations - use a esp8366/32 (or anything with low power requirements). If you need to process data (video stream), or do other calculations, potentially while controlling many different sensors/things - you'll likely want a raspberrpi/similar

[jonaswi]

Thanks for the tips! I will order a esp8266 and check it out.

[c22]

Unless you love soldering wires to tiny little smt pads I'd recommend looking for one of the "development boards" based on the 8266 (or as others have pointed out in this thread the bigger, faster, stronger, esp32). Not only will you get some through-hole connections to some subset of the pins, but you'll also get an onboard power supply and probably a usb port for programming so you can get right to cooking.

[jonaswi]

Thanks! Will do some research and then try to order the right one.

[true_tuna]

A cat or your cat specifically?

[Havoc]

That’s amazing

[fdjlasdfjl]

I could actually use exactly that. Do you have a blog outlining how you did it, or the code on github by any chance?

[jonaswi]

No sadly not. I'd love to write about it but my English is just not good enough to write a compelling story. Writing it in German and then having it translated is always a bit of a hassle. But I may consider it. At the moment I have an offer of the door drive manufacturer for doing a "home story" about the solution. If that will happen, it will definitely be released in English.

I will open source everything once I'm happy with the security and the ability to configure it.

[blotter_paper]

For what it's worth, I didn't have any clue that English wasn't your first language until you said it.

[justusthane]

Likewise! Although perhaps part of it is the additional effort it takes them to write in English, which would be understandable.

[freedomben]

I've been having pretty good luck with a friend who runs stuff through Google translate, and then I (a native English speaker) fix it up to make it more natural. Might be worth a try. I bet there's plenty of people on HN for example that would do that for you.

[rorykoehler]

Deepl.com is light years ahead for English to German and vice versa.

[hermitdev]

I wouldn't underestimate your English skills. What you've written here is perfectly serviceable.

[theelous3]

> No sadly not. I'd love to write about it but my English is just not good enough to write a compelling story.

Reads like a monty python sketch.

[true_tuna]

Your English is amazing. Don’t let it stop you.