An automatic laser turret playing with a cat.

Entertain Your Cats Automatically With LazerPaw

Most of us would agree that kittens are very cute, but require lots of attention in return. What would you do if you adopted three abandoned cats but didn’t have all day to play with them? [Hoani Bryson] solved his problem by building LazerPaw — an autonomous, safe way to let your cats chase lasers.

Having recently tinkered with computer vision in the form of OpenCV, [Hoani] decided he would make a laser turret for his cats to play with. An infrared camera, used so that the LazerPaw works in the dark, is mounted to the laser and the Raspberry Pi. These electronics are then mounted on a servo-based pan/tilt module, which is in turn mounted with two smartphone clamps to the ceiling. That way, when the cats chase the laser, they will be looking away from the beam source. Additionally, if the device is aiming directly at a cat, the laser is turned off. Finally, [Hoani] added some NeoPixels with an Arduino-based controller for extra hacker vibes.

The LazerPaw’s software takes in a 30 FPS stream from a webcam, scales it down for performance, and applies a threshold filter to it. When a black pixel, which is assumed to be a cat, is detected, it “pushes” the camera away from it depending on how close to the laser it is. The effect of this is that every time a cat catches up to the laser, it moves away again. The processed images are also sent to an interactive website for remote cat playtime. Finally, there is also a physical start button so you don’t need WiFi to use it.

Is your cat more of a sunbather than a deadly murder beast? Maybe it’ll like this cat chair that follows the sun.

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Litter Box Sensor Lets You Know Exactly What The Cat’s Been Up To

In our experience, there’s rarely any question when the cat uses the litter box. At all. In the entire house. For hours. And while it may be instantly obvious to the most casual observer that it’s time to clean the thing out, that doesn’t mean there’s no value in quantifying your feline friend’s noxious vapors. For science.

Now of course, [Owen Ashurst] could have opted for one of those fancy automated litter boxes, the kind that detects when a cat has made a deposit and uses various methods to sweep it away and prepare the box for the next use, with varying degrees of success. These machines seem like great ideas, and generally work pretty well out of the box, but — well, let’s just say that a value-engineered system can only last so long under extreme conditions. So a plain old-fashioned litterbox suffices for [Owen], except with a few special modifications. A NodeMCU lives inside the modesty cover of the box, along with a PIR sensor to detect the cat’s presence, as well as an MQ135 air quality sensor to monitor for gasses. It seems an appropriate choice, since the sensor responds to ammonia and sulfides — both likely to be present after a deposit. Continue reading “Litter Box Sensor Lets You Know Exactly What The Cat’s Been Up To”

Robotic Fox Is Part Dog, Part Cat — Just Like The Real Thing

Foxes are cat software running on dog hardware, or so they say. And [Will Cogley] seems to have taken that to heart with this 3D-printed robotic fox, which borrows heavily from projects like Boston Dynamics Spot robodog. True, the analogy breaks down a bit when you include MIT’s Cheetah on the inspiration list, but you get the point.

Very much a work in progress — [Will]’s RoboFox lacks both a head and a tail, which he aims to add at some point — there are some interesting design elements on display here. Whereas commercial quadruped robots tend to use expensive harmonic drives for the legs, [Will] chose simpler, cheaper hobby servos for his fox’s running gear. Each leg has three of them — one each for the upper and lower leg, and another that moves the whole leg in and out relative to the body. The dual-servo design for the leg is particularly interesting — one servo drives the upper leg directly, while the other servo drives the lower leg through a gear drive and a captive bearing arrangement connected to a parallelogram linkage. The result is a quite compact assembly that still has twelve degrees of freedom, and isn’t anywhere near as “floppy” as you might expect from something driven by hobby servos.

The video below shows off the design details as well as some of the fox’s construction, including some weirdly anatomically correct poses while it’s on its back. The fox is still getting its legs — you can see a few times when the servos get the jitters, and the umbilical is clearly a hindrance for such a lightweight robot. But [Will] has made a great start here, and we’re keen to see RoboFox progress. Although we’re not sure about giving the future head animatronic eyes.

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

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

[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

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

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!