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1901 points l2silver | 4 comments | | HN request time: 0.974s | source

Maybe you've created your own AR program for wearables that shows the definition of a word when you highlight it IRL, or you've built a personal calendar app for your family to display on a monitor in the kitchen. Whatever it is, I'd love to hear it.
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michaeltbuss ◴[] No.35740798[source]
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

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1. dangond ◴[] No.35741010[source]
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...

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2. ksaj ◴[] No.35741297[source]
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.

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3. ceejayoz ◴[] No.35741313[source]
We put an AirTag on our cat's collar. Works like a charm.
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4. neuronic ◴[] No.35750847{3}[source]
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.