2026-02-10 03:30:48
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!
2026-02-10 02:00:41
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.
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!
[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.
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.
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!
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.
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.
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.
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.
2026-02-10 00:30:27
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.
Featured Art: Royal Courts of Justice in London about 1870, Public Domain
2026-02-09 23:00:59
The BBC recently published an exposé revealing that some Chinese subscription sites charge for access to their network of hundreds of hidden cameras in hotel rooms. Of course, this is presumably without the consent of the hotel management and probably isn’t specifically a problem in China. After all, cameras can now be very tiny, so it is extremely easy to rent a hotel room or a vacation rental and bug it. This is illegal, China has laws against spy cameras, and hotels are required to check for them, the BBC notes. However, there is a problem: At least one camera found didn’t show up on conventional camera detectors. So we wanted to ask you, Hackaday: How do you detect hidden cameras?
Commercial detectors typically use one of two techniques. It is easy to scan for RF signals, and if the camera is emitting WiFi or another frequency you expect cameras to use, that works. But it also misses plenty. A camera might be hardwired, for example. Or store data on an SD card for later. If you have a camera that transmits on a strange frequency, you won’t find it. Or you could hide the camera near something else that transmits. So if your scanner shows a lot of RF around a WiFi router, you won’t be able to figure out that it is actually the router and a small camera.
The other common method uses a beam of light or a laser to try to see reflections of lenses, which will be retroreflective. The user views the room through a viewfinder, and any light that comes directly back will show up in the view. Despite some false positives, this method will find cameras even if they are not powered or transmitting. Even shining a flashlight, maybe from the same cell phone, around a dark room might uncover some camera devices.
There are a few other techniques. If you assume a spy camera probably uses IR lighting to see you at night, you can scan for that. A good tip is that your cell phone camera can probably see IR. (Test it on an IR remote control.) So looking around with your phone camera is a good, free way to find some cameras. A thermal imager might show hidden equipment, too, although it might be hard to determine if it is actually a camera or not.
You might be thinking: just look for the camera. But that’s not always simple. In the BBC article, the camera was the size of a pencil eraser. Not to mention, a quick search of your favorite retailer will reveal cameras made to look like smoke detectors, stuffed toys, USB chargers, and more. You can even get small cameras that can mount a fake button or screw head on the lens.
[Project Farm] has a video that tests a few detectors. The problem, of course, is that there are different kinds of cameras. Detecting the test camera doesn’t mean it will detect all cameras. Still, you can get some idea of how effective some detectors are compared to others.
Your Turn?
Given that none of the current ways to detect cameras work perfectly, what would you build to find them? Maybe an NLJD? Or maybe some tech to blind them? Tell us what you think in the comments.
2026-02-09 20:00:04
Sometimes you just know that you have the best ever idea for a hardware product, to the point that you’re willing to quit your job and make said product a reality. If only you can get the product and its brilliance to people, it would really brighten up their lives. This was the starry-eyed vision that [Simon Berens] started out with in January of 2025, when he set up a Kickstarter campaign for the World’s Brightest Lamp.
At 50,000 lumens this LED-based lamp would indeed bring the Sun into one’s home, and crowdfunding money poured in, leaving [Simon] scrambling to get the first five-hundred units manufactured. Since it was ‘just a lamp’, how hard could it possibly be? As it turns out, ‘design for manufacturing’ isn’t just a catchy phrase, but the harsh reality of where countless well-intended designs go to die.
The first scramble was to raise the lumens output from the prototype’s 39K to a slight overshot at 60K, after which a Chinese manufacturer was handed the design files. This manufacturer had to create among other things the die casting molds for the heatsinks before production could even commence. Along with the horror show of massive US import taxes suddenly appearing in April, [Simon] noticed during his visit to the Chinese factory that due to miscommunication the heatsink was completely wrong.
Months of communication and repeated trips to the factory follow after this, but then the first units ship out, only for users to start reporting issues with the control knobs ‘scraping’. This was due to an issue with tolerances not being marked in the CNC drawings. Fortunately the factory was able to rework this issue within a few days, only for users to then report issues with the internal cable length, also due to this not having been specified explicitly.
All of these issues are very common in manufacturing, and as [Simon] learned the hard way, it’s crucial to do as much planning and communication with the manufacturer and suppliers beforehand. It’s also crucial to specify every single part of the design, down to the last millimeter of length, thickness, diameter, tolerance and powder coating layers, along with colors, materials, etc. ad nauseam. It’s hard to add too many details to design files, but very easy to specify too little.
Ultimately a lot of things did go right for [Simon], making it a successful crowdfunding campaign, but there were absolutely many things that could have saved him a lot of time, effort, lost sleep, and general stress.
Thanks to [Nevyn] for the tip.
2026-02-09 17:00:31
As anyone who extrudes plastic noodles knows, the glass transition temperature of a material is a bit misleading; polymers gradually transition between a glass and a liquid across a range of temperatures, and calling any particular point in that range the glass transition temperature is a bit arbitrary. As a general rule, the shorter the glass transition range is, the weaker it is in the glassy state, and vice-versa. A surprising demonstration of this is provided by compleximers, a class of polymers recently discovered by researchers from Wageningen University, and the first organic polymers known to form strong ionic glasses (open-access article).
When a material transforms from a glass — a hard, non-ordered solid — to a liquid, it goes through various relaxation processes. Alpha relaxations are molecular rearrangements, and are the main relaxation process involved in melting. The progress of alpha relaxation can be described by the Kohlrausch-Williams-Watts equation, which can be exponential or non-exponential. The closer the formula for a given material is to being exponential, the more uniformly its molecules relax, which leads to a gradual glass transition and a strong glass. In this case, however, the ionic compleximers were highly non-exponential, but nevertheless had long transition ranges and formed strong glasses.
The compleximers themselves are based on acrylate and methacrylate backbones modified with ionic groups. To prevent water from infiltrating the structure and altering its properties, it was also modified with hydrophobic groups. The final glass was solvent-resistant and easy to process, with a glass transition range of more than 60 °C, but was still strong at room temperature. As the researchers demonstrated, it can be softened with a hot air gun and reshaped, after which it cools into a hard, non-malleable solid.
The authors note that these are the first known organic molecules to form strong glasses stabilized by ionic interactions, and it’s still not clear what uses there may be for such materials, though they hope that compleximers could be used to make more easily-repairable objects. The interesting glass-transition process of compleximers makes us wonder whether their material aging may be reversible.
