Building A Rad Bluetooth Speaker That Didn’t Really Exist

[Nick] came across an awesome Bluetooth speaker online, only, there was a problem. It didn’t really exist—it was just a render of a device that would be nice to have. Of course, there was an obvious solution—[Nick] just had to build the device for real!

The key to the aesthetic of the build is the external case. [Nick] was able to recreate the rough design of the rendered device in SolidWorks, before having the components produced on a resin 3D printer which provided excellent surface finish. Internally, the Bluetooth audio receiver was cribbed from an old pair of wireless headphones. However, a little more oomph was needed to make the speaker really usable, so [Nick] hooked the audio output up to a small MAX98306 amplifier board and a pair of 3 W speakers. The tiny tactile buttons from the headphone PCB wouldn’t do, either. For a nicer feel, [Nick] hacked in a set of four hall effect keyboard switches to control the basic functions.

The result is a Bluetooth speaker that looks as rad as the rendered unit, only you can actually take it outside and bump some tunes! It recalls us of some fine up-cycling work we’ve seen done to vintage 80s radios in a similar vibe.

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Hackaday Links: March 15, 2026

Some days, it feels like we’re getting all the bad parts of cyberpunk and none of the cool stuff. Megacorps and cyber warfare? Check. Flying cars and holograms? Not quite yet. This week, things took a further turn for the dystopian with the news that a woman was hospitalized after an altercation with a humanoid robot in Macau. Police arrived on scene, took the bot into custody, and later told the media they believed this was the first time Chinese authorities had been called to intervene between a robot and a human.

The woman, reportedly in her seventies, was apparently shocked when she realized the robot was standing behind her. After the dust settled, the police determined it was being operated remotely as part of a promotion for a local business. We’ve heard there’s no such thing as bad publicity, but we’re not sure the maxim holds true when you manage to put an old lady into the hospital with your ad campaign.

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New Aluminum-Based Catalyst Could De-Throne Platinum Group

Platinum-group metals (PGMs) are great catalysts, but they’re also great investments — in the sense that they are very, very expensive. Just ask the guy nicking car exhausts in the Walmart parking lot. If one could replace PGMs with a more common element, like, say the aluminum that makes up over 8% the mass of this planet, it would be a boon to the chemical industry, and a bane to meth addicts. Researchers at King’s College, London have found a way to do just that, with a novel form of aluminum called cyclotrialumane.

The aluminum trimer is exactly what the ‘tri’ in the name makes it sound like: three aluminum atoms, bonded in a triangular structure that is just pointy and stick-outy enough to poke into other molecules and make chemistry happen. OK, not really — you can see from the diagram above it’s not nearly that simple — but the point is that the shape makes it a good catalyst. The trimer structure is useful in large part because it is very stable, allowing reactions to be catalyzed in a large variety of solutions.

The researchers specifically call out their trialuminum compound as effective at splitting H2 in to H+ ions, as well as ethene polymerization. Both of those are important industrial reactions, but that’s only a start for this trialuminum wonder catalyst, because the researchers claim it can catalyze totally new reactions and create previously-unknown chemicals.

If you never took chemistry, or it’s been too many years since you last slept through that class, we have a primer on catalysts here. By accelerating chemical reactions, catalysts have enabled some neat hacks, like anything involving platinum-cure silicone.

Thanks to [Lightislight] for the tip! Hacks do appear here on their own, but you can always use our tips line to catalyze the synthesis of a particular article.


Header image adapted from: Squire, I., de Vere-Tucker, M., Tritto, M. et al. A neutral cyclic aluminium (I) trimer. Nat Commun 17, 1732 (2026). https://doi.org/10.1038/s41467-026-68432-1

An animation shows an open document in LibreOffice Write. In the document are some hexadecimal opcodes. The operator selects these opcodes and changes their font to Z80 Sans, at which point they are displayed as assembly mnemonic codes.

Disassembling Opcodes With A Font

Those who stay into the forbidden realm of font rendering quickly learn how convoluted and arcane it can be – LaTeX is a fully Turing-complete programming language, Unicode has over eighty invisible characters, and there are libraries that let you execute WebAssembly in a font. A great example of a font’s hidden capabilities is Z80 Sans, a font that disassembles Z80 opcodes to assembly mnemonics.

If one pastes Z80 opcodes into a word processor and changes their font to Z80 Sans, the codes are rendered as their assembly mnemonics. The font manages this by abusing the Glyph Substitution Table and Glyph Positioning Table, two components of the OpenType standard. Fonts define relations between characters (internal representations used by the computer, such as ASCII and Unicode) and glyphs (the graphics actually displayed).

In some cases, though, the way a character is displayed depends on where it appears in a word, or what appears around it (Arabic characters are a common example, but an example from English is the ligature “æ”). Z80 Sans defines all the possible glyphs for each nibble of the opcodes, then used a recursive descent parser to generate substitution rules which display the correct glyphs in context.

For a deeper dive into the pitfalls of text graphics, check out this font rendering engine written for a hobby OS. You can also use fonts to play games or talk to an LLM.

DR-DOS Is Back, But Not Quite As We Knew It

If you weren’t around for the early PC era, or were a little more casual about operating systems, you could perhaps be forgiven for not knowing that DOS is not synonymous with MS-DOS. MS-DOS was just Microsoft’s implementation — or rather, an implementation they purchased — of a Disk Operating System, one that was…let’s just say “inspired by” Digital Research’s CP/M.

Digital Research shot back with DR-DOS, an operating system that was both compatible with and much superior in some ways to MS-DOS. The last version was released in 1991, after Novell bought the struggling Digital Research. Now it’s back, or at least, it’s on its way back with a fully clean-room implementation by a fellow who calls himself [CheeseWeezel] on Reddit.

He’s gone so far as to purchase the trademark, so this re-creation is the official DR-DOS. In any case [CheeseWeezel]’s DR-DOS is considered version 9.0, and is currently in Beta. The clean-sheet re-implementation of DR-DOS’s API was sadly necessary due to the rather tortured history of the IP after DR was bought by Novel, who sold DR-DOS to Caldera, who briefly open-sourced the code before retracting the license and selling on. Some of you may remember a controversy where a previous rights holder, DR DOS INC, was found purloining FreeDOS code in violation of the GPL. Perhaps because of that, [CheeseWeezel] isn’t using any old code, and isn’t open-sourcing what he’s done. Right now, the beta of DR-DOS 9 is free for non-commercial use, but as is standard for EULAs, that could change at any time without warning. [CheeseWeezel] is still working full compatibility, but at this point it at least runs DOOM.

Still, given the origins of DOS in Digital Research’s early work on CP/M, it warms the heart to see what many of us thought of as the “true” DOS survive in some form in the 21st century. Arguably it already had, in the form of SvarDOS, but you can’t use that to make smug jokes about your operating system having PhD instead of a measly master’s. If you did not like DOS, we recall the joke from Mac users was that those were the degrees needed to operate the PC. Speaking of DOS, you don’t necessarily need a retrocomputer to run it.

Thanks to [OldDOSMan] for the tip!

Relays Run This Balanced Ternary Adder

If you’re at all familiar with digital computing, you’ll know that computers represent everything in binary values of one and zero. Except that’s not technically the only way to do computing! You can use any numerical system you like if you build your hardware to suit, as [Jeroen Brinkman’s] ternary adder demonstrates.

As you might guess from the prefix, “ternary” refers to a base-3 numerical system. In this case, [Jeroen] implemented a balanced ternary system, which effectively uses values of -, 0, and + instead of just 1 and 0. The adder is built using relay logic, and is designed to handle 4 trits—the ternary equivalent of bits, where each trit can have one of the three aforementioned states. On a hardware level, trit states are represented with voltages of -5, 0, or 5 V in this case, and are handled with special tri-state switching elements that [Jeroen] constructed out of simple SPDT relays.

[Jeroen]’s write-up does a great job of explaining both ternary basics as well as the functioning of the adder. It’s also quite intuitive because it’s possible to see the relays clicking away and the LEDs flashing on and off as the circuit does its work to add values stored in ternary format.

If you’re trying to get your head around ternary computing from the very lowest level, this project is a great place to start. We’ve seen base 3 hardware built before, too—like this simple ternary computer lashed together from accessible components.

If you’re cooking up your own computing apparatus that uses some weird number system or something, remember—we’d love to hear about it on the tipsline!

A Smart Printer Enclosure For The Open Source World

3D printing has had its time to spread its wings into the everyday home, yet many of those homes lack the proper ventilation to prevent the toxic VOCs from escaping. Because of this, [Clura] has put together an entire open-sourced smart enclosure for most open concept printers.

While certain 3D printers or filament choices lend themselves to being worse than others, any type of plastic particles floating around shouldn’t find their way into your lungs. The [Clura] enclosure design includes HEPA and carbon filters in an attempt to remove this material from the air. Of course, there’s always the choice to have a tent around your printer, but this won’t actually remove any VOCs and air located inside a simple enclosure will inevitably escape.

What makes this enclosure different from other, either commercial or open-source designs, is the documentation included with the project. There are kits available for purchase, which you may want for the custom PCB boards for smart features such as filament weighing or fume detection. Even still, if you don’t want to purchase these custom boards the Gerber files are available on their GitHub page.

As smart as this enclosure is, it still won’t fix the issues of what happens to the toxins in your print after it’s done printing. If you are interested in this big picture question, you are not alone. Make sure to stay educated and help others learn by checking out this article here about plastic in our oceans.