[Dan]’s project from last year slipped past us until now, but his Ghost Frame is a great example of tying some modern hackable hardware together with online resources into a clean result, and we like the clear idea behind it. The Ghost Frame is so named because its purpose is literally to show pictures of people (and cats) that do not exist in the physical world.
To make it all work, [Dan] used an Adafruit PyPortal as the guts of the device. It pulls images from ThisPersonDoesNotExist.com (which displays computer-assembled images of faces that do not represent actual living people) and displays them as though they were pictures in a digital photo frame. Formatting the image to show up nicely on the PyPortal’s 320 x 240 display took a little extra work; [Dan] solved that problem with a small PHP script to convert the image to a bitmap and scale it correctly in the process. The PyPortal makes fetching resources from the web simple, so this kind of fiddling didn’t present much of an obstacle to [Dan]’s artistic vision.
What about the cats? Well, it turns out that ThisCatDoesNotExist.com is also out there, and Ghost Frame can happily display computer-generated images of nonexistent cats as easily as it shows imaginary people. However, it does seem that the state of nonexistent cat generation is lagging somewhat behind that for people. The site usually gets it right, but results are occasionally (amusingly) bizarre as you can see here.
The aim of the device is to automate the motion of a laser pointer to make playing with the cats a hands-free operation. A pan-tilt servo mechanism has a low-power red laser pointer fitted, and the assembly is hooked up to a NodeMCU microcontroller. Based on the ESP8266, it allows the system to be controlled remotely over WiFi. Various sweeps can be automatically commanded from a smartphone, or the servo position can be controlled manually.
It doesn’t take long after getting a cat in your life to learn who’s really in charge. Cats do pretty much what they want to do, when they want to do it, and for exactly as long as it suits them. Any correlation with your wants and needs is strictly coincidental, and subject to change without notice, because cats.
[Alvaro Ferrán Cifuentes] almost learned this the hard way, when his cat developed a habit of exploring the countertops in his kitchen and nearly turned on the cooktop while he was away. To modulate this behavior, [Alvaro] built this AI Nerf turret gun. The business end of the system is just a gun mounted on a pan-tilt base made from 3D-printed parts and a pair of hobby servos. A webcam rides atop the gun and feeds into a PC running software that implements the YOLO3 localization algorithm. The program finds the cat, tracks its centroid, and swivels the gun to match it. If the cat stays in the no-go zone above the countertop for three seconds, he gets a dart in his general direction. [Alvaro] found that the noise of the gun tracking him was enough to send the cat scampering, proving that cats are capable of learning as long as it suits them.
Some of us here at Hackaday are cat lovers, but we also understand that a plethora of unwanted cats using a suburban back garden can be bothersome, and a few years ago we featured a project from Aussie YouTuber [Craig Turner], in which he created a motion-detecting water spray for use as a relatively harmless cat repellent. Now he’s back with an updated version which is a little slicker and easier to make.
At its heart is the same PIR-turns-on-water operation, but this time there is a solenoid valve and purpose-built nozzle instead of a car central locking actuator and a lawn sprayer. Doing the electronic work is an off-the-shelf PIR module, so there is no longer any need to hack a security PIR detector. Add in some pipe sections and PTFE tape with a bit of hot glue, and the result is a far more professional and streamlined device. The video gives a full run-down on construction, though we notice he neglected to emphasise the polarity of his protection diode so keep an eye out if you follow his example.
So if the thought of a continuous supply of free feline company courtesy of your neighbours is not for you then now you are equipped to send them packing. The latest video incarnation of the project is below the break, but if you are in search of the original then you can go back to our coverage at the time.
A feline’s appetite is rarely sated, and cat owners around the world are routinely treated to an early morning wake up call to remind them of this fact. To solve this problem, many turn to automated feeders. However, such devices usually handle only dry foods, with a simple hopper system. [Vikram Hao] instead went above and beyond, building a fully automated wet food cat feeder.
The device is a great example of effective automation. It’s fully capable of dispensing a single can of cat food, as well as opening the can, serving the food and disposing of the waste in an integrated bin. Currently, it has a maximum capacity of 9 cans, though this can be increased by simple alterations to the hopper and trash bin. Unsurprisingly, all manner of steppers, servos and brushed motors work in concert to achieve this feat. An Arduino Mega 2560 serves as the brains, providing plenty of IO to run everything as easily as possible.
Most humans take a year to learn their first steps, and they are notoriously clumsy. [Hartvik Line] taught a robotic cat to walk [YouTube link] in less time, but this cat had a couple advantages over a pre-toddler. The first advantage was that it had four legs, while the second came from a machine learning technique called genetic algorithms that surpassed human fine-tuning in two hours. That’s a pretty good benchmark.
The robot itself is an impressive piece inspired by robots at EPFL, a research institute in Switzerland. All that Swiss engineering is not easy for one person to program, much less a student, but that is exactly what happened. “Nixie,” as she is called, is a part of a master thesis for [Hartvik] at the University of Stavanger in Norway. Machine learning efficiency outstripped human meddling very quickly, and it can even relearn to walk if the chassis is damaged.
Have you ever looked at your cat and thought “You know, my kitten really needs an electric skateboard!” Probably not, but this seems to have happened to [Kim Pimmel] while looking at his cat MIDI, so he decided to build one. This process involved building a simple, low powered skateboard with a Feather mainboard and motor controller combined with a laser-cut switch mechanism. When [Kim] puts a treat into the mechanism, the cat pulls the switch and the skateboard moves forward, moving into a brave new e-skateboarding feline future. MIDI looks somewhat unimpressed by this whole business, but I suspect that as long as the treats keep coming, he will be happy to keep on truckin’. Now, if he can just figure out how to persuade the cat to ollie, we will be really getting somewhere.
Feline tomfoolery seems to be a regular pastime here on these pages, and more than just a quest for easy moggy-driven clickbait. A lot of cat feeders and cat finders abound, but this project isn’t the only cat-operated one. Our readers’ pets can probably spot an Arduino a mile away by now.