Simple Wi-Fi Cat Door Solves The Extra Critter Problem, And Nothing More

November 2, 2022 by Dan Maloney 9 Comments

Anyone with an outdoor cat in their life knows their propensity for bringing home offerings, in the form of critters in various stages of the process of becoming ex-critters. And anyone with a hacker in their life knows that there’s a tendency to throw technology at this problem. But sometimes, the simplest solutions are the best.

Take this simple stepper-powered cat door lock. For [Jason Winfield], the essential problem with his outdoor cat’s late-night demands for reentry was having to manually unlock the cat door after a quick visual check that no midnight snacks were along for the ride. Such activity tends to make it hard to get back to sleep. One natural reaction to this would be to completely automate the process with machine learning to recognize the offering and deny entry; we’ve seen exactly that before, after all. But recognizing that the disruptive part was the getting up to check bit, [Jason] just whipped up a simple stepper-driven lock with an ESP8266 microcontroller. With a 3D-printed case and a battery pack, and a nearby Wi-Fi camera, the lock denies entry to the cat until he gets a look at it, at which point he simply hits the lock’s webpage to unlock the door. The video below would show the lock in action, except the cat buggered off once it got a whiff of the doings. Cat’s gonna cat.

What we appreciate about this project is its simplicity. It solves the problem with the minimum feature set, which is something we see too little of sometimes. It’s also got some nice ideas, like the non-captive bolt that can be removed to unlock the door if the battery dies. Smart thinking, [Jason], and sweet dreams.

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Monitoring A Cat’s Litter Box Usage With AI

August 30, 2022 by Lewin Day 7 Comments

[Estefannie] is a proud cat owner, but one of her cats has a bad habit of eating plastic. That means she needs to keep an eye on that cat’s bowel movements, but with two cats in the house, it’s difficult to know who did what. Thus, she whipped up an AI system to log her cats bathroom visits and give her peace of mind.

It’s not the most glamorous project — [Estefannie] notes she took over 50,000 pictures of her cats using the litterbox to train Microsoft Azure’s Custom Vision model. But after some work, it could readily identify which cat was using the litter box when fed images from a NoIR camera. The system then differentiates between number 1 and number 2 via the time the cat spends in the litter box. It’s not perfect, but it works.

The Raspberry Pi runs a Node.JS server to collate the results, paired with a website front-end for easy data display. That way, anyone on [Estefannie’s] WiFi network can see who did what from a browser. We’ve seen cat litter boxes put on the Internet of Things before, and we’ve even seen people hack litterbox DRM, too.

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Hackaday Links: May 8, 2022

May 8, 2022 by Dan Maloney 13 Comments

Russia’s loose cannon of a space boss is sending mixed messages about the future of the International Space Station. Among the conflicting statements from Director-General Dmitry Rogozin, the Roscosmos version of Eric Cartman, is that “the decision has been made” to pull out of the ISS over international sanctions on Russia thanks to its war on Ukraine. But exactly when would this happen? Good question. Rogozin said the agency would honor its commitment to give a year’s notice before pulling out, which based on the current 2024 end-of-mission projections, means we might hear something definitive sometime next year. Then again, Rogozin also said last week that Roscosmos would be testing a one-orbit rendezvous technique with the ISS in 2023 or 2024; it currently takes a Soyuz about four orbits to catch up to the ISS. So which is it? Your guess is as good as anyones at this point.

At what point does falsifying test data on your products stop being a “pattern of malfeasance” and become just the company culture? Apparently, something other than the 40 years that Mitsubishi Electric has allegedly been doctoring test results on some of their transformers. The company has confessed to the testing issue, and also to “improper design” of the transformers, going back to the 1980s and covering about 40% of the roughly 8,400 transformers it made and shipped worldwide. The tests that were falsified were to see if the transformers could hold up thermally and withstand overvoltage conditions. The good news is, unless you’re a power systems engineer, these aren’t transformers you’d use in any of your designs — they’re multi-ton, multi-story beasts that run the grid. The bad news is, they’re the kind of transformers used to run the grid, so nobody’s stuff will work if one of these fails. There’s no indication whether any of the sketchy units have failed, but the company is “considering” contacting owners and making any repairs that are necessary.

For your viewing pleasure, you might want to catch the upcoming documentary series called “A League of Extraordinary Makers.” The five-part series seeks to explain the maker movement to the world, and features quite a few of the luminaries of our culture, including Anouk Wipprecht, Bunnie Huang, Jimmy DiResta, and the gang at Makers Asylum in Mumbai, which we assume would include Anool Mahidharia. It looks like the series will focus on the real-world impact of hacking, like the oxygen concentrators hacked up by Makers Asylum for COVID-19 response, and the influence the movement has had on the wider culture. Judging by the trailer below, it looks pretty interesting. Seems like it’ll be released on YouTube as well as other channels this weekend, so check it out.

But, if you’re looking for something to watch that doesn’t require as much commitment, you might want to check out this look at the crawler-transporter that NASA uses to move rockets to the launch pad. We’ve all probably seen these massive beasts before, moving at a snail’s pace along a gravel path with a couple of billion dollars worth of rocket stacked up and teetering precariously on top. What’s really cool is that these things are about as old as the Space Race itself, and still going strong. We suppose it’s easier to make a vehicle last almost 60 years when you only ever drive it at half a normal walking speed.

And finally, if you’re wondering what your outdoor cat gets up to when you’re not around — actually, strike that; it’s usually pretty obvious what they’ve been up to by the “presents” they bring home to you. But if you’re curious about the impact your murder floof is having on the local ecosystem, this Norwegian study of the “catscape” should be right up your alley. They GPS-tagged 92 outdoor cats — which they dryly but hilariously describe as “non-feral and food-subsidized” — and created maps of both the ranges of individual animals, plus a “population-level utilization distribution,” which we think is a euphemism for “kill zone.” Surprisingly, the population studied spent almost 80% of their time within 50 meters of home, which makes sense — after all, they know where those food subsidies are coming from.

Meowing Box Will Befuddle Your Friends

January 29, 2022 by Lewin Day 11 Comments

If you don’t own a cat, hearing the sound of one meowing from somewhere in the house probably comes as quite a shock. The Cat Prank box built by [Reuben] promises to deliver such hilarity with aplomb.

The idea is simple: hide the Cat Prank box in a cupboard or other space in a friend’s house, and it will meow from its secret location. When found, either the light sensor or motion sensor will trigger the yowling of an angry feline, with hopefully startling effects.

An Arduino Mini is the brains of the operation, paired with an XY-V17B sound module which plays the required animal wailings. There’s also a 433 MHz radio module that lets the prankster trigger meowing via remote control.

Code is available for those wishing to build their own. We’d love to see a mod with a time delay built in, so the device could be hidden and left to start meowing at some later date when the prankster is far away.

Similar work has graced these pages before, like the devilishly fiendish OpenKobold design. Just make sure your friends are receptive to such jokes before you go ahead and invest time and hardware in the prank!

Smart Pet Feeder Is Well Engineered

April 19, 2021 by Anool Mahidharia 19 Comments

Having pets can sometimes be more demanding than raising kids. Pet owners obviously love and adore their pets, but anything that can be done to reduce their “chores” can be a welcome relief. One big pain point is feeding them at the right time and in the right amount, especially when it comes to cats. As the saying goes, “Dogs have Masters, Cats have Staff! ”

[Sebastian] had had it with his cat [Strachu] nagging him at odd hours for food. Luckily, [Sebastian] is a skilled maker, and his IoT Cat Feeder is not only practical, but also extremely well engineered. He designed and built it from scratch, and the beautiful, final version shows the effort he put in to it. His requirements were quite straightforward. It had to integrate with his home automation system, had to dispense food based on a regular schedule, send him a notification at other times of the day when the feeder detected the cat so he could decide if the cat deserved a special treat or not, and allow him to manually dispense cat food. Finally, he also wanted it to be easy to take apart so he could wash the parts that are in contact with food.

For the electronics, [Sebastian] designed a custom board to hold the ESP12F module and all the other associated parts. Everything, other than the stepper motor is mounted on the PCB. A PIR sensor is used for cat detection. A piezo buzzer lets the cat know that food is ready. A push button can be used to manually dispense food when required. The ESP8266 is flashed with ESPhome which allows control via simple yet powerful configuration files and control them remotely through the Home Assistant addon. If you’re interested in taking a look under the hood, [Sebastian] walks through some of the key code blocks on the ESP side, as well as the various configuration and setting options for the Home Assistant.

But by far the most effort he needed was in getting the mechanical design perfected. He had to go through several rounds of prototype iterations – after all, his cat deserved the very best in feeder design. The basic parts of the design are simple – a stepper motor drives an auger that pushes the cat food from the main container and deposits it in the bowl. Check out the detailed assembly instructions and pictures on his blog. The best part of his design is how easy it is to take it apart the feeder for cleaning. The stepper motor is held in place by a snap fit end piece without using any screws. The main body then just slides out from the top of the electronics box. Check out [Sebastian]’s cat feeder video after the break for details.

If this design makes you hanker to make one for your cat too, head over to his blog post and provide your mail address and [Sebastian] will send all the files for the project.

If your cat isn’t satisfied with dry food nuggets, you probably ought to build this Automated Cat Feeder That Handles Wet Food With Aplomb.

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Serving The Feline Masters: A Chair To Follow The Sunny Spot

January 17, 2021 by Danie Conradie 21 Comments

Terry Pratchett once wrote, “In ancient times cats were worshipped as gods; they have not forgotten this”. [Jonathan]’s cat has clearly not forgotten, and makes it loudly known whenever her favorite chair needs to be moved to stay in the spot of sunlight. He was looking for a fun hack anyway, so he decided to give in to her majesty’s demands, and automated the task.

[Jonathan] first considered adding motorizing the chair itself, but decided to keep it simple and just drag the chair across the room with a spool attached to a motor. The rope spool was attached to a small geared DC motor, mounted on a salad bowl base, and connected to an ESP8266 via a motor driver. The ‘8266 is running NodeMCU with a web server that accepts simple motor commands through a RESTful API. This setup can’t reset the chair to it’s starting position at the end of the day, but this is a small price to pay for simplicity. The motor was a bit underpowered, but it only needed to move the chair in small distances at a time, so [Jonathan] removed the chair’s back to reduce the weight, and upped the motor voltage.

Determining when and how far to move the chair is the second part of the challenge. [Jonathan] considered a simple lookup table for the time of day, but the motor’s movement wasn’t consistent enough. The final solution was a set of three BH1750 digital ambient light sensors to give feedback. A pair of sensors on the chair determines its position relative to the sunny spot, by comparing light levels to a reference sensor mounted in the window. These light sensors are also attached to NodeMCUs, and send movement commands to the winding unit as necessary.

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Watch A Fast Sand Plotter Plow Patterns At Speed

September 22, 2020 by Donald Papp 21 Comments

[Mark]’s sand table wisely has a glass top.

Most of us have probably seen a video of a sand drawing table at work, in which a steel ball — magnetically-coupled to a gantry under a layer of sand — lazily draws geometric patterns with utter precision and zen-like calmness. That’s all well and good, but [Mark Rehorst] thinks it can also be interesting to crank up the speed and watch the ball plow through sand just as physics intended. There’s a deeper reason [Mark] is working at this, however. Faster drawing leads to less crisp results, but by how much, exactly? To answer this, [Mark] simply ran his table (which is named The Spice Must Flow) at both fast and slow speeds and documented the results.

These two images show the difference between running the table at 100 mm/s versus 500 mm/s. The slower speed is noticeably crisper, but on the other hand the faster speed completed the pattern in about a fifth of the time. [Mark] says that as the ball aggressively accelerates to reach target speeds, more sand is thrown around over existing lines, which leads to a loss of detail.

Crisper detail, or a faster draw? Which is “better” depends on many things, but it’s pretty clear that [Mark]’s cat finds the fast version more exciting. You can see [Mark]’s table at high speed and the cat’s reaction in the video, embedded below.

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