Hacker News Reader

Comment by michaeltbuss | Hacker News Reader

Every night, at 3 AM, my cat will meow and paw at the bedroom door like a banshee. I tried everything to get him to stop, including the off-the-shelf air sprayers that trigger with motion.

Eventually, I decided to build my own. I 3D printed a case and trigger for an air sprayer can, created some electronics with an ESP32 and RF trigger, and wrote my own "motion detection" logic - this time with an ultrasonic sensor, which works much better in the dark.

Now, the cat knows that a meow or paw will get him sprayed, and my wife and I can finally sleep!

I also built an air filtration system for my 3D printer, a level checker for my water softener, and a custom keepsake box that only opens with an RFID chip that you can read more about on my blog: https://www.mikebuss.com/blog

View on HN

Your blog is amazing, I would love to keep up by adding it to my feed reader but I'm not finding any RSS/Atom feeds.

Thanks! I always forget to add RSS when redoing the site. Here's a link to that: http://mikebuss.com/rss.xml

In all my previous houses I just cut a hole in the door. $50s from a big box store for the proper door and a jig saw. I think they even sell templates you can attach to the door to make them more seamless.

But also I'm not trying to keep the cat out so there's that. I just like the door closed

I solved this by letting the cat open the door from both sides.

From one side, the cat can just push open the door. The closing force on the door comes from a small weight hanging on a string, which goes from the top corner of the door to an eye screw on the wall and down to the weight. The weight is adjusted to be just barely enough to pull the door closed, so the door is easy for the cat to push open. The cat walks through and then the door closes very gently and quietly.

From the other side, the cat can pull open the door. I stuck a little hook-handle on the bottom corner of the door, and the cat learned to paw the handle and pull the door open. Because the door closes so slowly and gently, it's easy for the cat to get through.

This lets the cat can come and curl up with me whenever he wants. It's quieter than a flappy cat door; he can come and go without bothering me or waking me up.

I have the same cat friendly door closer! Very useful for a good night’s sleep. But now my cat is so old he mostly stays curled up on the bed poor fellow.

Heads up that a) those commercial/industrial door closer thingies aren't that expensive if the door isn't too heavy, but better than that b) they have spring door hinges, so you can install those and the door will self-close. Not sure its cat friendliness but it works for keeping the door closed.

We were lucky enough that our cat seems to prefer screaming under the door rather than pawing at the door, and stuffing a blanket underneath thankfully caused her to simply give up.

She still attacks the door loudly when playing with her toys at 5 AM if we forget to confiscate them though...

The first time we ever had cats, we put little bells on their collars so we knew where they were in the house.

One night is all it took for us to remove those bells. Never again.

We put an AirTag on our cat's collar. Works like a charm.

I "loudly" put a tiny snack on the floor. It doesn't matter where the cat is, after 300ms delay it's basically a grey flash and then he's there.

Serious question - have you considered just leaving the door open?

> ... meow and paw like a banshee.

Was this in March by any chance?

Very clever. I would love to re-create this, we have the same issue with our cat.

We need this.

Reply on news.ycombinator.com