When you really love your pawed, feathered, or scaled friends, you build projects for them. (Well, anyway, that’s what’s happened to us.) For the 2025 Pet Hacks Challenge, we asked you to share your favorite pet-related hacks, and you all delivered. So without further ado, here are our favorites, as well as the picks-of-the-litter that qualified for three $150 DigiKey gift certificates. Spoiler alert: it was a clean sweep for team cat.
I was watching Ben Krasnow making iron nitride permanent magnets and was struck by the fact that about half of the video was about making a magnetometer – a device for measuring and characterizing the magnet that he’d just made. This is really the difference between doing science and just messing around: if you want to test or improve on a procedure, you have to be able to measure how well it works.
When he puts his home-made magnet into the device, Ben finds out that he’s made a basically mediocre magnet, compared with samples out of his amply stocked magnet drawer. But that’s a great first data point, and more importantly, the magnetometer build gives him a way of gauging future improvements.
Of course there’s a time and a place for “good enough is good enough”, and you can easily spend more time building the measurement apparatus for a particular project than simply running the experiment, but that’s not science. Have you ever gone down the measurement rabbit hole, spending more time validating or characterizing the effect than you do on producing it in the first place?
In a marvelous college lecture in front of a class of engineering students, V. Hunter Adams professed his love for embedded engineering, but he might as well have been singing the songs of our people – the hackers. If you occasionally feel the need to explain to people why you do what you do, at fancy cocktail parties or something, this talk is great food for thought. It’s about as good a “Why We Hack” as I’ve ever seen.
Among the zingers, “projects are filter removers” stuck out. When you go through life, there are a lot of things that you kinda understand. Or maybe you’ve not even gotten around to thinking about whether you understand them or not, and just take them for granted. Life would all simply be too complicated if you took it all sufficiently seriously. Birdsong, Bluetooth, the sun in the sky, the friction of your car’s tire on various surfaces. These are all incredibly deep subjects, when you start to peel back the layers.
And Hunter’s point is that if you are working on a project that involves USB, your success or failure depends on understanding USB. There’s no room for filters here – the illusion that it “just works” often comes crashing down until you learn enough to make it work. Some of his students are doing projects cooperatively with the ornithology department, classifying and creating birdsong. Did you know that birds do this elaborate frequency modulation thing when they sing? Once you hear it, you know, and you hear it ever more.
So we agree with Hunter. Dive into a project because you want to get the project done, sure, but pick the project because it’s a corner of the world that you’d like to shine light into, to remove the filters of “I think I basically understand that”. When you get it working, you’ll know that you really do. Hacking your way to enlightenment? We’ve heard crazier things.
Just a quickie for anyone who is in the neighborhood, today the Open Source Hardware Association’s annual Open Hardware Summit conference starts in Edinburgh, Scotland. If you’re able to make it, it’s a microcosm of the open-source hardware world, and full of great talks and great hackers.
If you’re not in Scotland, they have a livestream on YouTube that you should check out, as well as a Discord server for discussions during the event. It’s going on right now!
We wrote up a video about speeding up Arduino code, specifically by avoiding DigitalWrite. Now, the fact that DigitalWrite is slow as dirt is long known. Indeed, a quick search pulls up a Hackaday article from 2010 demonstrating that it’s fifty times slower than toggling the pin directly using the native pin registers, but this is still one of those facts that gets periodically rediscovered from generation to generation. How can this be new again?
First off, sometimes you just don’t need the speed. When you’re just blinking LEDs on a human timescale, the general-purpose Arduino functions are good enough. I’ve written loads of useful firmware that fits this description. When the timing requirements aren’t tight, slow as dirt can be fast enough.
But eventually you’ll want to build a project where the old slow-speed pin toggling just won’t cut it. Maybe it’s a large LED matrix, or maybe it’s a motor-control application where the loop time really matters. Or maybe it’s driving something like audio or video that just needs more bits per second. One way out is clever coding, maybe falling back to assembly language primitives, but I would claim that the right way is almost always to use the hardware peripherals that the chipmakers gave you.
For instance, in the end of the video linked above, the hacker wants to drive a large shift register string that’s lighting up an LED matrix. That’s exactly what SPI is for, and coming to this realization makes the project work with timing to spare, and in just a few lines of code. That is the way.
Which brings me to the double-edged sword that the Arduino’s abstraction creates. By abstracting away the chips’ hardware peripherals, it makes code more portable and certainly more accessible to beginners, who don’t want to learn about SPI and I2C and I2S and DMA just yet. But by hiding the inner workings of the chips in “user friendly” libraries, it blinds new users to the useful applications of these same hardware peripherals that clever chip-design engineers have poured their sweat and brains into making do just exactly what we need.
This isn’t really meant to be a rant against Arduino, though. Everyone has to start somewhere, and the abstractions are great for getting your feet wet. And because everything’s open source anyway, nothing stops you from digging deeper into the datasheet. You just have to know that you need to. And that’s why we write up videos like this every five years or so, to show the next crop of new hackers that there’s a lot to gain underneath the abstractions.
We’re tremendously excited to be able to announce that the Hackaday Supercon is on for 2025, and will be taking place October 31st through November 2nd in Pasadena, California.
Supercon is about bringing the Hackaday community together to share our great ideas, big and small. So get to brainstorming, because we’d like to hear what you’ve been up to! Like last year, we’ll be featuring both longer and shorter talks, and hope to get a great mix of both first-time presenters and Hackaday luminaries. If you know someone you think should give a talk, point them here.
The Call for Participation form is online now, and you’ve got until July 3rd 10th to get yourself signed up.
Honestly, just the people that Supercon brings together is reason enough to attend, but then you throw in the talks, the badge-hacking, the food, and the miscellaneous shenanigans … it’s an event you really don’t want to miss. And as always, presenters get in for free, get their moment in the sun, and get warm vibes from the Hackaday audience. Get yourself signed up now!
We’ll have more news forthcoming in the next few weeks, including the start of ticket sales, so be sure to keep your eyes on Hackaday.
On the podcast, [Tom] and I were talking about the continuing saga of the libogc debacle. [Tom] has been interviewing some of the principals involved, so he’s got some first-hand perspective on it all – you should really go read his pieces. But the short version is that an old library that many Nintendo game emulators use appears to have cribbed code from both and open-source real-time operating system called RTEMS, and the Linux kernel itself.
You probably know Linux, but RTEMS is a high-reliability RTOS for aerospace. People in the field tell me that it’s well-known in those circles, but it doesn’t have a high profile in the hacker world. Still, satellites run RTEMS, so it’s probably also a good place to draw inspiration from, or simply use the library as-is. Since it’s BSD-licensed, you can also borrow entire functions wholesale if you attribute them properly.
In the end, an RTOS is an RTOS. It doesn’t matter if it’s developed for blinking LEDs or for guiding ICBMs. This thought got [Tom] and I to thinking about what other high-reliability open-source code is out there, hidden away in obscurity because of the industry that it was developed for. NASA’s core flight system came instantly to mind, but NASA makes much of its code available for you to use if you’re interested. There are surely worse places to draw inspiration!
What other off-the-beaten-path software sources do you know of that might be useful for our crowd?
