Mysterious Files PH

Due to historical engineering decisions made many decades ago, a great many irrigation systems rely on solenoid valves that operate on 24 volts AC. This can be inconvenient if you’re trying to integrate those valves with a modern smart home control system. [Johan] had read that there were ways to convert these valves to more convenient DC operation, and dived into the task himself.

As [Johan] found, simply wiring these valves up to DC voltage doesn’t go well. You tend to have to lower the voltage to avoid overheating, since the inductance effect used to limit the AC current doesn’t work at DC. However, even at as low as 12 volts, you might still overheat the solenoids, or you might not have enough current to activate the solenoid properly.

The workaround involves wiring up a current limiting resistor with a large capacitor in parallel. When firing 12 volts down the line to a solenoid valve, the resistor acts as a current limiter, while the parallel cap is initially a short circuit. This allows a high current initially, that slowly tails off to the limited value as the capacitor reaches full charge. This ensures the solenoid valve switches hard as required, but keeps the current level lower over the long term to avoid overheating. According to [Johan], this allows running 24V AC solenoid valves with a 12V DC supply and some simple off-the-shelf relay boards.

We’ve seen similar work before, which was applied to great effect. Sometimes doing a little hack work on your own can net you great hardware to work with. If you’ve found your own way to irrigate your garden as cheaply and effectively as possible, don’t hesitate to notify the tipsline!

Now, we can’t call these LEGO key caps for obvious reasons, but also because they don’t actually work with standard LEGO. But that’s just fine and dandy, because they’re height-adjustable key caps that use the building block principle.

Now you could just as easily build wells as the dome shape pictured here, and I’d really like to see that one of these days.

In the caption of the gallery, [paper5963] mentions foam. As far as I’ve studied the pictures, it seems to be all 3D-printed material. If they were foam, they would likely be porous and would attract and hold all kinds of nastiness. Right?

[paper5963] says that there are various parts that add on to these, not just flat tops. There are slopes and curves, too. They are also designing these for narrow pitch, and say they are planning to release the files. Exciting!

Fold-able Keyboard Goes Anywhere

[pinya] says this is a remake of their Crabapplepad V2 into something that folds. They take it along in their backpack and use it either with a phone or a Lenovo Legion Go linux tablet. The original PCB was designed for this possibility, and now it’s a thing.

This is the same board as the CrabappleV2, but cut into three pieces and rejoined with flexy silicone wire. That stuff is already great; here’s another use case for it.

The hinges are the friction type you’d find on a laptop, so they’re strong and can stay in any position. The way they’re mounted doesn’t allow for much tenting, but it does allow for a few degrees. Otherwise, the whole thing would become unstable.

This baby has soldered brown Kailh chocs (yay!) with the diodes buried snugly beneath them. The switches were still exposed and snagging on things in the backpack, so [pinya] whipped up a nice little felt case for it.

Since there’s still enough space at the top of the board, [pinya] might add a built-in phone stand. I’m interested to see how that goes with the weight of the phone and all.

The Centerfold: These 3D-Printed Key Caps

And now for some completely different 3D-printed key caps, this time from [strings_and_tines]. These are beautiful, and I love the font of the legends and the texture of the tops. Really wish I could touch them. Evidently [strings_and_tines] was not finding key caps with large enough legends for their silakka54 and so they whipped these up using a Bambu Lab A1 with AMS to handle the two colors.

Do you rock a sweet set of peripherals on a screamin’ desk pad? Send me a picture along with your handle and all the gory details, and you could be featured here!

Historical Clackers: the Lovely Waverley

This elegant late-Victorian piece is not only beautiful to look at, it has a special place in history. The Waverley was one of only four typewriters ever produced with a rear-downstrike arrangement of type bars. Basically, the bars strike the paper from the top and rear of the machine.

In case you’re wondering, the other three with this distinction are the Brooks, the Fitch, and the North’s, which this resembles quite a lot.

So, how does a rear-downstriker operate? The main issue is feeding the paper. The inventors Edward Smith Higgins and Henry Charles Jenkins created a system that fed the sheet from the front of the platen, wound around it, and then was expelled into that lovely basket on the front, where they would become neatly coiled and out of the visual path to the platen.

The Waverley has other notable features such as a shifting system that completely disengages the lower case type bars and engages the separate, upper case type bars. So each type bar only has one character.

It also has proportional spacing, but only for the widest letters (M and W). The carriage moves a little bit further to account for their extra width.

There’s a separate Space key in the upper right that moves the carriage only the width of one character, whereas the Space bar moves it twice as far to separate the words. This last is one of those features you’d have to train yourself to do, I would think: you can simultaneously push the Space bar while typing the last letter of a word, and then you’re immediately ready to type the next word.

Unfortunately, the Waverley Type-Writer Co. disbanded after just one year of production because of a lack of working capital. It may have just been too complex and thus difficult to produce.

Finally, a Truly Modular Keyboard Complete Input System

Would you like a modular keyboard? Or would you prefer an entire input system? Dutch company Naya are back with the Connect, which looks less like a ‘sensory nightmare’ than the Create, their ergonomic modular keyboard.

I suppose it depends on your work and play. I for one would not make use of most of the mouse-like bits, but I would appreciate a tack-on 10-key thing and a set of macro keys for the other side.

And I’m sure left-handers will appreciate that the 10-key thing can go on either the left or right. But you don’t have to use it as a 10-key. It’s essentially just a second macro module with 24 keys. (Not pictured.)

I love New Atlas’ opening salvo: “This might just be the most engineered desktop gear I’ve ever come across.” Much like the ergonomic Create, the four round things are as follows: a customizable trackpad, a 40 mm  trackball, a rotary encoder, and a 6-DoF spatial mouse. I will spare you their ethereal names.

The keyboard itself is a 75%, 85-key number in a unibody of machined aluminium. It has hot-swappable Kailh Choc V2s, and those keycaps are allegedly dished, but they look flat as Kansas to me. Oh, okay; if you look at the many pictures on Kickstarter, you can see the dishing.

Here’s the kicker: it doesn’t come with everything. You either go with the base keyboard and add modules, or get the Dock (the thing on the right up there with four keys and a hole) and attach modules to that. Also, it’s in the Kickstarter phase as I alluded, but it’s something like 4,000% funded already, so.

The keyboard by itself isn’t that much — $119 for early birds — and the Dock is even cheaper. But they aren’t going to ship for more than a year, so consider that.

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Got a hot tip that has like, anything to do with keyboards? Help me out by sending in a link or two. Don’t want all the Hackaday scribes to see it? Feel free to email me directly.

In the early days of AI, a common example program was the hexapawn game. This extremely simplified version of a chess program learned to play with your help. When the computer made a bad move, you’d punish it. However, people quickly realized they could punish good moves to ensure they always won against the computer. Large language models (LLMs) seem to know “everything,” but everything is whatever happens to be on the Internet, seahorse emojis and all. That got [Hayk Grigorian] thinking, so he built TimeCapsule LLM to have AI with only historical data.

Sure, you could tell a modern chatbot to pretend it was in, say, 1875 London and answer accordingly. However, you have to remember that chatbots are statistical in nature, so they could easily slip in modern knowledge. Since TimeCapsule only knows data from 1875 and earlier, it will be happy to tell you that travel to the moon is impossible, for example. If you ask a traditional LLM to roleplay, it will often hint at things you know to be true, but would not have been known by anyone of that particular time period.

Chatting with ChatGPT and telling it that it was a person living in Glasgow in 1200 limited its knowledge somewhat. Yet it was also able to hint about North America and the existence of the atom. Granted, the Norse apparently found North America around the year 1000, and Democritus wrote about indivisible matter in the fifth century. But that knowledge would not have been widespread among common people in the year 1200. Training on period texts would surely give a better representation of a historical person.

The model uses texts from 1800 to 1875 published in London. In total, there is about 90 GB of text files in the training corpus. Is this practical? There is academic interest in recreating period-accurate models to study history. Some also see it as a way to track both biases of the period and contrast them with biases found in data today. Of course, unlike the Internet, surviving documents from the 1800s are less likely to have trivialities in them, so it isn’t clear just how accurate a model like this would be for that sort of purpose.

Instead of reading the news, LLMs can write it. Just remember that the statistical nature of LLMs makes them easy to manipulate during training, too.

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Featured Art: Royal Courts of Justice in London about 1870, Public Domain

We start this week with a bit of a good news/bad news situation. On February 6th, the Relativistic Heavy Ion Collider (RHIC) was shut down after 25 years of operation. Located at Brookhaven National Laboratory in Upton, New York, the RHIC was the only operating particle collider in the United States, and along with the Large Hadron Collider (LHC), was one of only two heavy-ion colliders in existence.

So that’s the bad news. The good news is that the RHIC is going dark so that the Electron-Ion Collider (EIC) can take its place. Planned for activation in the mid-2030s, the EIC will occupy the same tunnel as the RHIC and reuse much of the same hardware. As the name implies, it will be used to collide electrons.

Switching gears (no pun intended) to the world of self-driving cars, Waymo’s chief safety officer, Dr. Mauricio Peña, made a surprising admission this week during a U.S. Senate hearing. When asked what his company’s vehicles do when they are presented with a situation that their on-board systems can’t resolve, Dr. Peña explained that they would contact a human “remote assistance operator.” He further clarified that these individuals, located both in the US and the Philippines, don’t literally drive the car remotely. Still, Senator Ed Markey of Massachusetts questioned not only the company’s transparency on the issue of remote assistance, but the idea that individuals overseas could be making decisions on how vehicles should operate on US roadways.

While on the subject of a hyped-up technology that hasn’t quite delivered, CNN posed an interesting question — in an article titled “No, but seriously: What’s going on with bitcoin?“, David Goldman pointed out that the cryptocurrency recently dropped below $63,000 USD for the first time in over a year and a half (as of today, it has rebounded slightly to just under $71,000). He goes on to explain that global uncertainty and rapidly improving AI technology are partly to blame, although we’re honestly not quite sure how that second one works. But more importantly, he theorizes that the market is returning to where it was before the 2024 presidential election. Then candidate Trump embraced the digital currency and promised to remove restrictions he claimed were holding it back. This naturally caused a bump in Bitcoin value after he won the White House, but as those changes have yet to materialize, the excitement is apparently wearing off.

In software news, the remaining Windows users who still haven’t been beaten into submission by Microsoft will have another feature taken away from them; as of February, the operating system’s integrated 3D Viewer is officially being deprecated. The tool allows users to inspect various types of 3D files, including STLs, and was added to Windows back when Microsoft was convinced “mixed reality” was going to be a thing. Anyone who has 3D Viewer installed will still be able to use it, but it will no longer be available for download officially from Microsoft. On the bright side, the web-based alternative that Microsoft recommends seems pretty slick.

Those holding out hope for life on the Red Planet will be excited to read the recent report from NASA which claims that the organic compounds discovered on Mars by the Curiosity rover can’t be fully explained by non-biological processes. In other words, while there are geological processes that could have produced some of the molecules detected, and some could have been deposited on the planet by meteorites, none of the possibilities studied could account for them all. The researchers caution that this doesn’t mean there is current or active life on the Martian surface, however, as we still don’t fully understand the timescales required to break these molecules down. Curiosity might have sniffed out the signs of life, but that life could still have died off billions of years ago.

On the subject of space, a recent post about the number of satellites in low-Earth orbit by mathematician John Cook got some debate going. He runs the numbers and argues that given the current number of LEO satellites (~12,500), and the area of space that they operate in, each bird has roughly 100,000,000 km³ to itself. Not exactly the close quarters flying that we’ve been hearing so much about recently with the proliferation of satellite constellations such as SpaceX’s Starlink. That said, others were quick to point out that his math only really works out if all the satellites were evenly distributed, which is obviously not the case in the real world. So while his estimate is probably a bit too generous, it still helps put into context just how mind-bogglingly big space actually is.

Finally, for those who would prefer to scroll endlessly through something a bit more intellectually stimulating than social media, check out Xikipedia. This open source project takes the content from the Simple English Wikipedia and turns it into a never ending feed that you can browse, complete with an algorithm that will suggest articles to you based on your personal interests. What do you call the opposite of doomscrolling — maybe knowledgescrolling?

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The middle of the 20th century produced a revolution in understated stylish consumer design, some of which lives on today. The reality of living in a 1950s or ’60s house was probably to be surrounded by the usual mess of possessions from many past decades, but the promise was of a beautiful sleek and futuristic living space. Central to this in most homes would have been the TV set, and manufacturers followed the trends of the age with cases that are now iconic. Here in 2026 we put up with black rectangles, but fortunately there’s Cordova Woodworking with a modern take on a retro TV cabinet.

We’ve put the build video below, and it’s a wonderfully watchable piece of workshop titillation in a fully-equipped modern shop. While we appreciate they’ve put the design up for sale, we think many Hackaday readers could come up with their own having already been inspired. One thing we notice over the originals is that they use “proper” wood for their case, when we know the ’60s version would have had veneer-faced ply or chipboard.

The result is a piece of furniture which nicely contains the modern TV and accessories, but doesn’t weigh a ton or dominate the room in the way one of the originals would have, much less emit that evocative phenolic hot-electronics smell. We’d have one in our living room right now. Meanwhile if you’d like a wallow in mid-century TV, we have you covered.

Computers are very good at doing exactly what they’re told. They’re still not very good at coming up with helpful suggestions of their own. They’re very much more about following instructions than using intuition; we still don’t have a digital version of Jeeves to aid our bumbling Wooster selves. [Sherrin] has developed something a little bit intelligent, though, in the form of a habit detector for use with Home Assistant.

In [Sherrin]’s smart home setup, there are lots of things that they wanted to fully automate, but they never got around to implementing proper automations in Home Assistant. Their wife also wanted to automate things without having to get into writing YAML directly. Thus, they implemented a sidecar which watches the actions taken in Home Assistant.

The resulting tool is named TaraHome. When it detects repetitive actions that happen with a certain regularity, it pops up and suggests automating the task. For example, if it detects lights always being dimmed when media is playing, or doors always being locked at night, it will ask if that task should be set to happen automatically and can whip up YAML to suit. The system is hosted on the local Home Assistant instance. It can be paired with an LLM to handle more complicated automations or specific requests, though this does require inviting cloud services into the equation.

We’ve featured lots of great Home Assistant hacks over the years, like this project that bridges 433 MHz gear to the smart home system. If you’ve found your own ways to make your DIY smart home more intelligent, don’t hesitate to notify the tipsline!

Earlier this year Donut Lab caused quite the furore when they unveiled what they claimed was the world’s first production-ready solid state battery, featuring some pretty stellar specifications. Since then many experts and enthusiasts in the battery space have raised concerns that this claimed battery may not be real, or even possible at all. After seeing the battery demonstrated at CES’26 and having his own concerns, [Ziroth] decided to do some investigating on what part of the stated claims actually hold up when subjected to known science.

On paper, the Donut Lab battery sounds amazing: full charge in less than 10 minutes, 400 Wh/kg energy density, 100,000 charge cycles, extremely safe and low cost. Basically it ticks every single box on a battery wish list, yet the problem is that this is all based on Donut’s own claims. Even aside from the concerns also raised in the video about the company itself, pinning down what internal chemistry and configuration would enable this feature set proves to be basically impossible.

In this summary of research done on Donut’s claimed battery as well as current battery research, a number of options were considered, including carbon nanotube-based super capacitors. Yet although this features 418 Wh/kg capacity, this pertains only to the basic material, not the entire battery which would hit something closer to 50 Wh/kg.

Other options include surface-redox sodium-ion chemistry with titanium oxide. This too would allow for fast charging and high endurance, but Donut has already come out to state that their battery is not capacitor-based and uses no lithium, so that gets shot down too.

Combined with the ‘cheap’ and ‘scalable’ claims this effectively shoots down any potential battery chemistry and architecture. Barring some amazing breakthrough this thus raises many red flags, especially when you consider Donut Lab’s major promises for investors that should make any reasonable person feel skittish about pouring money into the venture.

Sadly, it seems that this one too will not be the battery breakthrough that we’re all waiting for. Even new chemistries like sodium-ion are struggling to make much of inroads, although lithium-titanate shows real promise. Albeit it not with amazing power density increases that would make it better than plain lithium-ion for portable applications.