A Split Keyboard Designed For Human Hands

A surprising number of things we use in everyday life retain most of their design cues from their 19th century ancestors. The bicycle retains the same basic design as it had in 1890, as does the sewing machine, the toilet, the car, and of course, the keyboard and the QWERTY layout from old typewriters. But we aren’t doomed to have our technology perpetually living in the past. [Paul] wanted a keyboard designed around human hands, rather than being designed around a machine, so he built this unique split keyboard.

The design of this specific keyboard went through around 50 iterations before he was comfortable with it. Other design goals here were for it to be portable, and the split nature of this certainly makes it more compact as does the use of low-profile switches. Each finger’s column is angled and spaced based on the needs of that finger, with the ring finger keys sitting higher and the index finger columns angled inward. Each thumb has access to three keys, one of which is the spacebar and the other two layer keys, which is what enables this design to get down to only 36 total keys.

When thinking about it for any length of time, the modern keyboard’s design holdovers from the 1800s are fairly wasteful compared to this split, ergonomic version. Especially when looking at the spacebar, which ties up both thumbs and only performs a single task, there’s a lot of opportunity for modern designs to be more efficient, more portable, and easier on one’s body. Feel free to take this to the extreme and use all three dimensions, as long as you aren’t particularly concerned with portability.

Exploring The Downsides Of Cooling Roof Paint

The idea of painting a roof or wall white in order to reflect sunshine and keep the building’s insides cool is hardly a new one, and even in the loosest interpretation of the word ‘white’ it generally works pretty well. This is also what [NightHawkInLight] found after using an off-the-shelf silicone-based coating for his shed’s tin roof, though with a few caveats.

One might say that this is mostly a problem for people who live in non-desert climates — like Michigan in this case — yet it’s undeniable that having a cooler indoors in a high-humidity climate will inevitably lead to a higher indoor humidity level. This was the first issue that was encountered, though it mostly meant that instead of running an air conditioner eight hours a day, a weekly dehumidifier session was required, which was at least less expensive in terms of kWh.

While the current silicone-based paint on the roof stays above ambient, in a subsequent test both [NightHawkInLight]’s DIY sub-ambient cooling paint and a commercial option get a sample panel down to around ambient temperature, which could cool down the roof even more. Of course, in this case the humidity issues would get worse, with likely condensation forming that would have to be dealt with.

Overall, a cooling paint on the roof is a pretty thing even if you’re not living in the desert, but you have to be able to tame the resulting humidity and condensation issues.

Continue reading “Exploring The Downsides Of Cooling Roof Paint”

Hackaday Europe 2026: Fluid Kernels And Optimizing C++ For MCUs

Oftentimes, when we’re using a microcontroller, we’re whipping up some very specific code focused on executing a particular task. The device is set up to execute code that does exactly what we want with minimal overhead. However, sometimes, there are scenarios where it pays to go with a somewhat heavier setup, wherein the microcontroller runs an operating system for the benefits that offers.

Federico Terraneo came to Hackaday Europe to discuss this very topic. He talks about kernel architecture, real-time operating systems, and how to best use C++ in the world of microcontrollers.

Continue reading “Hackaday Europe 2026: Fluid Kernels And Optimizing C++ For MCUs”

A Thoroughly Modern Minimalist Transceiver

Making a radio is so often a case of taking tried and tested designs and working with them to create something new. It’s a safe way to make something that works. [Riyas] however has gone for an entirely different tack, creating an entirely modern transceiver with as much as possible going on in the silicon.

At its heart are three integrated circuits, the familiar Si5351 as a transmit VFO, an Si4372 receiver, and an RP2040 tying it all together. This microcontroller functions both as controller, and as an ADC to provide a software defined radio via its USB port. The Si4372 having an internal SDR architecture and its output being digitized again is not lost on us.

It’s for digital modes and CW only, but we’d venture the opinion that those are where the interesting stuff is anyway. We certainly like it for its simplicity, and also for the one-cable solution it offers. So many other designs need a sound card and extra cables, this one makes for a lot less clutter. We hope we’ll see more development on this design over time, it could become a favorite in the homebrew rig stakes.

Meanwhile the Si5351 is notoriously annoying to program. A while back we covered a library that might help, if you get stuck.

From A Ten-Line Script To A Real Utility With Codex

I’m an experienced programmer, and I’ve worked in many different languages. Sometimes being a programmer is a two-edged sword. You want to accomplish something, and you can do it easily — but it can be a lot of work to do it right. Maybe more work than you want to do.

Normally, I’ll kick out a few lines of script for something I want and be done, accepting that it isn’t production-hardened. This time, however, I decided to try an AI tool to see whether they could do the work I was too lazy to do myself. While I’ve played with chatbots, I wanted to try one of the dedicated coding agents, in this case, Codex. Outside of asking ChatGPT to write a simple function or find the cause of an error message, I haven’t done much coding with AI assistance, so I was interested to see what these agents brought to the table.

A Radio Problem

The problem was simple: I wanted an easy way to put buttons on my Linux desktop that launched Internet radio stations. Sure, I could open a player and paste in a long URL, but I’m far too lazy to remember all those URLs.

I searched for a way to make Shortwave — an Internet radio player — open a URL from the command line. Apparently, you can’t. Google Gemini suggested writing a script that launches cvlc, the command-line VLC player, with the URL as an argument.

That’s easy, so I did it. Of course, then I had to find the stream URLs for all my favorite stations. It turns out that Radio Browser maintains an extensive database of stations. I considered scraping the site or using its API, but honestly, the little script was becoming too much of a project.

Besides, I was already struggling to manage the media player’s lifetime. I didn’t want a new station playing on top of one that was already running, and I wanted a command to stop playback, so the script had already grown larger than I first imagined.

My first version used a temporary file containing the player’s process ID so a future script execution could kill the old player. That usually works, but it isn’t very robust, and I knew it. But how much work did I really want to do here? I decided I had done enough and turned the rest over to Codex, OpenAI’s coding assistant.

Continue reading “From A Ten-Line Script To A Real Utility With Codex”

Rescuing A Rescue Device With A DIY Battery Pack

If you find yourself lost in the woods or adrift in the ocean, a GPS-enabled Personal Locator Beacon (PLB) is certainly a handy thing to have as it will pinpoint your location for rescuers. The one [Steve Jernigan] has is relatively affordable considering it might save your life one day, but it turns out that replacement batteries for the unit are extremely expensive and hard to come by because the manufacturer would rather you send the unit back to them for refurbishment. So naturally, he took it apart and figured out how to do it himself.

His DIY battery pack consists of a small custom PCB and pair of off-the-shelf 6 volt lithium manganese dioxide cells in a 3D printed enclosure that slots into the rear of the McMurdo PLB. In assembly video below, [Steve] shows how the pack goes together and demonstrates the use of a two-part potting compound in an effort to keep the elements at bay.

Before anyone says it — putting a homemade battery pack into a device which one day might be the only thing standing between you and death is probably not a great idea. [Steve] mentions in the description of this project that this is meant for backup purposes, and that you should really spring for a legitimate battery if there’s a chance you might actually need to be rescued at some point.

If you’re interested in battery pack hacking that doesn’t potentially risk life and limb, fixing the one that came with your cordless drill might be a better project to start with. Continue reading “Rescuing A Rescue Device With A DIY Battery Pack”

Miniaturized, Working Replica Of Vintage Leslie Speaker

Few pieces of vintage audio gear from the turn of the century (the previous one) inspire the kind of devotion that a Leslie speaker does. Sure, there are plenty of pieces that are rarer or more valuable, but the Leslie speaker has such a big following because of its uniqueness of physically moving sound around a room. Two rotating devices in the speaker physically direct the sound around the cabinet with musician-controlled speed, and this sound remains extremely difficult to reproduce faithfully without the moving components. But originals are enormous and meant for organs, so [Eric] built a 40% replica with a few modern touches for his guitar.

The build starts with a CAD model, where [Eric] works towards making the most accurate enclosure for his speaker as possible. The CAD model heads out to a CNC machine which can care most of the details into the wood, and he eventually is able to finish it, although it took a few tries with stains and paintbrushes of various types. For the speakers themselves, he’s using modern versions including modern brushless motors to drive the rotating elements. Like the original speaker, the high range of sound is sent through a rotating set of horns, of which one is only a counterweight, and the low range is directed out of the bottom of the cabinet through a large rotating drum. Both rotating elements here are 3D printed, and with everything put together and wired up [Eric] has a much more portable, faithful recreation of the original Leslie speaker.

There are some upgrades in the wiring too, which makes it work better with a guitar rather than for an organ. It’s also much lighter, and was a hit when he took it to let a few other guitarists to play as well. It’s not the first time we’ve seen the Leslie’s movement recreated for guitar, but it is the most alike to the classic 1930s-era speaker we’ve seen so far.

Continue reading “Miniaturized, Working Replica Of Vintage Leslie Speaker”