How To Avoid Getting Arc Flashed

September 3, 2026 by 3 Comments

After getting called out in the field to troubleshoot a large PV solar installation, [Derek] found himself suddenly in the midst of an arc flash, causing burns all over his face and arms. In a recent video he goes over the scenario that led up to this unfortunate event, as the holes in the Swiss cheese slowly lined themselves up, culminating in a high-current 480 VDC discharge nearly giving [Derek] a fatal embrace.

Despite being a professionally trained and certified professional, being called out to diagnose a weird issue on a slightly unusual solar farm’s electrical installation already worked against him. After having spent some time doing said troubleshooting, he finally tracked down the auxiliary transformer that normally powers the low-voltage gear, along with the spicy parts that should absolutely be unpowered after flipping the breaker into the ‘off’ position.

Testing for no power confirmed that the power had indeed been cut, which was when the wiring that normally connects the auxiliary transformer was spotted still lying just out of reach in the back of the cabinet. Clearly this was the cause behind one of the issues that the owner had been having.

This was when [Derek] decided to go to the light reach for this spool of wiring with a pair of pliers, into the – as it turned out – still live high-voltage side. One massive arc flash and hospital recovery later, [Derek] learned that the layout of the lines in the cabinet were different from usual, with the position of the roll of loose wiring being a potential hint that something was off.

The problem here was one of habituation, and the assumption that the system that he was working on was de-energized. The reason that he’s still with us being that the pliers acted as the current path instead of his body, and the arc flash cooked only the exposed parts of his skin, being mostly parts of his face and his hands.

Terrifyingly, [Derek] was working alone, and was forced to dial 911 somehow, with fingers that no longer registered on the iPhone’s touch screen on account of the skin having been turned into charcoal. While he doesn’t remember exactly how he managed to reach 911, it’s likely that the voice assistant finally connected him. The property owner also arrived and did what he could do to help before the ambulance arrived.

Overall, the lesson here is that complacency and assumptions are the killers here. Even if the layout of a high-voltage circuit is different in a way that makes no sense and there ought to be industry standards, when it’s you reaching into that cabinet such trivial details matter less than having ensured that there’s absolutely no power on anything, even if you know that there shouldn’t be. Reality only has to disagree with you once there.

[Derek] was lucky in the sense that the cabinet mostly shielded him from the arc flash’s intense heat, but over 19% of his skin was still burned, requiring skin grafts and an ongoing, very painful recovery. By sharing his story he hopes that he can prevent at least one other person reaching into that cabinet with some pliers for that ‘let me just quickly…’ moment.

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A Split Keyboard Designed For Human Hands

September 3, 2026 by 4 Comments

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

September 3, 2026 by 7 Comments

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.

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

September 3, 2026 by 2 Comments

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.

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A Thoroughly Modern Minimalist Transceiver

September 3, 2026 by 2 Comments

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

September 3, 2026 by 48 Comments

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.

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Rescuing A Rescue Device With A DIY Battery Pack

September 3, 2026 by 2 Comments

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” →