The Colmi R02 is one of the cheapest smart rings on the market. It costs about $20, and is remarkably easy to hack. [Floyd Steinberg] took advantage of this to turn it into a rather unique MIDI controller.

What makes the Colmi R02 somewhat unique is that the manufacturer did not try to lock out users from uploading their own firmware. You don’t even really need to “hack” it, since there is no code signing or encryption. You can just whip up your own firmware to make it do whatever you want.

To that end, [Floyd] set up the ring to act as a device for musical expression. When connected to a computer over Bluetooth, data from the ring’s accelerometer is converted into MIDI CC commands via a simple web app. The app allows the MIDI messages to be configured so they can control whatever parameter is desired. [Floyd] demonstrates the ring by using it to control filter cutoff frequencies on an outboard synthesizer, with great effect.

You could theoretically just strap an accelerometer to your hand with a microcontroller and achieve similar operation. However, the magic of this is that it costs only $20 and it’s already in a form factor that’s optimized for wearing on your finger. It’s hard to beat that.

Files are on GitHub for those eager to experiment. We’ve previously featured some hacks of this particular smart ring, too, with [Aaron Christophel’s] efforts directly inspiring this work.

youtube.com/embed/0aNxuAbEwvM?…

hackaday.com/2026/01/31/cheap-…

We were talking on the podcast about rope. But not just any rope – especially non-stretchy rope for using in a mechanical context. The hack in question was a bicycle wheel that swapped out normal metal spokes for lighter and stronger high-density polypropylene weave, and if you can tension up a bike wheel and ride it around, you know it’s not your garden-variety twine.

Now, it just so happens that I’ve got basically the same stuff in my parts drawer: some 1 mm diamaeter Dyneema-brand rope. This is an amazing material. It’s rated to a breaking strength of 195 kg (430 lbs) yet it weighs just under one gram per meter, and if you buy the pre-stretched variant, it’s guaranteed to stretch less than 1% of its length under load. It’s flexible, wears well, and is basically in every way superior to braided steel wire.

It’s nearly magical, and it’s just what you need if you’re making a cable robot or anything where the extreme strength and non-elongation characteristic are important. It’s one of those things that there’s just no substitute for when you need it, and that’s why I have some in my secret-ingredients drawer. What else is in there? Some high-temperature tape, low-temperature solder, and ultra-light-weight M3 PEEK screws for airplane building.

But our conversation got me thinking about the parts, materials, and products that are unique: for which there is just no reasonable substitute. I’m sure the list gets longer the more interesting projects or disciplines that you’re into. What are your secret ingredients, and what’s the specific niche that they fit into?

This article is part of the Hackaday.com newsletter, delivered every seven days for each of the last 200+ weeks. It also includes our favorite articles from the last seven days that you can see on the web version of the newsletter. Want this type of article to hit your inbox every Friday morning? You should sign up!

hackaday.com/2026/01/31/secret…

Generally, one opens a web browser or an app to use YouTube. However, if you’re looking to just listen to the audio, you can actually do that right from the terminal. You just need Shellbeats from [lalo-space].

Shellbeats is primarily intended for playing music from YouTube, and is well equipped for this task. It allows searching YouTube directly from the terminal, as well as streaming tracks or entire playlists from the command line interface. You can also make and edit playlists from within the tool, and even download the whole lot as MP3s if so desired. It’s all keyboard-operated and nicely lightweight. The overall experience isn’t dissimilar from operating a simple LCD-based MP3 player from 20 years ago.

There’s plenty of other fun stuff you can do in the terminal, too, as we’ve explored previously. If you’re working on your own media player hacks, be sure to notify us on the tipsline!

hackaday.com/2026/01/31/playin…

You’ve probably heard — we’re currently experiencing very high RAM prices due mostly to increased demand from AI data centers.

If you’ve been priced out of new RAM you are going to want to get as much value out of the RAM you already have as possible, and that’s where today’s hack comes in: if you’re on a Debian system read about ZRam for how to install and configure zram-tools to enable and manage the Linux kernel facilities that enable compressed RAM by integrating with the swap-enabled virtual memory system. We’ve seen it done with the Raspberry Pi, and the concept is the same.

Ubuntu users should check out systemd-zram-generator instead, and be aware that zram might already be installed and configured by default on your Ubuntu Desktop system.

If you’re interested in the history of in-kernel memory compression LWN.net has an old article covering the technology as it was gestating back in 2013: In-kernel Memory Compression. For those trying to get a grip on what has happened with RAM prices in recent history, a good place to track memory prices is memory.net and if you swing by you can see that a lot of RAM has gone up as much as four times in the last three or four months.

If you have any tips or hacks for memory compression on other platforms we would love to hear from you in the comments section!

hackaday.com/2026/01/31/surviv…

Go back a couple of generations, and rather than a laptop or a luggable, the office accessory of choice was a portable typewriter. As the 20th century wore on, the typewriter became electric before eventually being eclipsed by luggable and laptop computers. On YouTube, [Prototype] is turning back the clock, by turning an old Smith-Corona electric typewriter into a luggable computer– with a stretch goal of still being able to type.

Yeah, just gutting the typewriter and shoving an SBC inside wasn’t ambitious enough for [Prototype]: his goal is a working typewriter and an x86 gaming PC. To facilitate this, he guts the Smith-Corona keyboard, and 3D-prints a new top plate to add a little more vertical space in the old typewriter. The new top does recreate the original layout and the Corona switches get printed adapters to fit them to mechanical switches [Prototype] is using with a vibe-coded Arduino. Why one would bother with ChatGPT when QMK is right there, we could not say, but feel free to skip 6:20 to 15:00 if you’re watching the video but want to avoid that side quest.

Unfortunately, the “get the keyboard working” side-quest is either faked or deferred to video part II, which has not been posted yet. In this video he demonstrates that he can actuate a single hammer with a servo, but that’s a far cry from a working typewriter so, we’re really hoping he comes through on that promise in Part Two. Even if the build stops with just one hammer, that would give the tactile sound-and-feel that other builds turn to solenoids for. Squeezing a small-form-factor motherboard and graphics card into the old Smith-Corona is also going to be an interesting challenge. It’s certainly going to be a step up from using the keyboard as a terminal.

If you like this project but balk at the idea of destroying a working piece of vintage office equipment, it is possible to turn a typewriter into a USB keyboard non-invasively.

If you like this project at all, join us in thanking [Katie] for the tip. Not your cup of tea? Tell us what is, with a tip of your own.

youtube.com/embed/Bgk944awGcQ?…

hackaday.com/2026/01/30/crouch…

Not everyone will write their own optimizing compiler from scratch, but those who do sometimes roll into it during the course of ever-growing project scope creep. People like [Michael Moroz], who wrote up a long and detailed article on the why and how. Specifically, a ‘small library’ involving a few matrix operations for a Unity-based project turned into a static optimizing tensor compiler, called TensorFrost, with a Python front-end and a shader-like syntax, all of which is available on GitHub.

The Python-based front-end implements low-level NumPy-like operations, with development still ongoing. As for why Yet Another Tensor Library had be developed, the reasons were that most of existing libraries are heavily focused on machine learning tasks and scale poorly otherwise, dynamic flow control is hard to implement, and the requirement of writing custom kernels in e.g. CUDA.

Above all [Michael] wanted to use a high-level language instead of pure shader code, and have something that can output graphical data in real-time. Taking the gamble, and leaning on LLVM for some parts, there is now a functional implementation, albeit with still a lot of work ahead.

hackaday.com/2026/01/30/writin…

Need a plastic mesh in a custom pattern? 3D print it, no problem. But what if one needs a curved plastic mesh? That’s considerably harder to 3D print, but [Uncle Jessy]’s figured out a simple approach: 3D print the mesh flat, then break out a mold and a heat gun.

Of course, there are a few gotchas, but [Uncle Jessy] shares his tips for getting the most reliable results. The important part is to design and 3D print a mold that represents the final desired shape. Then print the mesh, and fit it into a frame. Heat things up with a heat gun, and press into the mold to deform the mesh while it’s still soft. It’s much easier seen than explained, so take a few moments to check out the video, embedded below the page break.
Custom eye inserts become a breeze.
Because the plastic in a mesh is so thin, [Uncle Jessy] says to keep the heat low and slow. The goal is to have the mesh stretch and deform, not melt.

Speaking of heat, when thermoforming, one usually needs to make the mold out of heat-resistant material. But the thermal mass of a mesh is so small that it really doesn’t matter much — there just isn’t enough heat trapped in the mesh to really damage a mold. As long as the mold is reasonably dense, there’s no need to go overboard with making it heat resistant.

The whole process takes a little practice, but since the meshes are so fast to print and use so little plastic it’s easy to experiment a little.

As for the meshes themselves, a simple way to print a mesh is just to print a disc with no top or bottom layers, only infill. Set the infill pattern to honeycomb, for example, for an easy hexagon mesh. We’ve seen a variant of this “exposed infill” idea used to create a desiccant container, and using it to print a mesh pattern easily is a neat trick, too.

Why might one need to reshape a mesh into a curve? Perhaps to custom-fit a costume piece, or make custom eye inserts for masks, as shown here. In any case, it’s a good technique to keep in the back of one’s mind, and if you put it to good use, drop us a tip!

youtube.com/embed/TsG89NgZJO8?…

hackaday.com/2026/01/30/need-a…

If you’re ordering pizza these days, you’re probably using a smartphone app or perhaps still making a regular old phone call. If you’re creative and a little bit tricky, though, you can order pizza right from your Sega Dreamcast. You just need to jump through a few hoops, as demonstrated by [Delux] and [The Dreamcast Junkyard] in the recent past.

You used to be able to order pizza on the Dreamcast natively, all the way back in 1999. However, the modern Domino’s website doesn’t really work on the ancient Dreamcast browser anymore. The simple fact is that web technology has advanced a long way in the last couple of decades, and Sega didn’t exactly spend a lot of time maintaining a browser on a console that died mere months after its rivals hit the market.

Thus, to place a pizza order on the Dreamcast these days, you need to work within its limitations. [Delux] uses the Dreamcast with the Broadband Adapter to access a PC on the local network via the XDP web browser. That PC is hosting Web Rendering Proxy, a tool which converts complicated modern websites into something a simpler machine can parse. From there, it’s a matter of connecting to the Domino’s website, and slowly clicking through the online ordering pages. Between the proxy delay, the Dreamcast’s glacial processing speed, and the clunky Domino’s ordering interface, it takes ages. Never before has adding coupons felt like such a hassle. Still, after 15 minutes of fuss, the order is completed… and a short time later, a hot fresh pizza arrives.

It’s a fun hack, but really it’s the PC running the proxy that’s doing the heavy lifting. In 2026, it’s far more elegant to order a pizza from your Nintendo Wii.

youtube.com/embed/dEMqq7-8K5s?…

hackaday.com/2026/01/30/orderi…

What filament is strongest? The real answer is “it depends”, but sometimes you have a simple question and you just want a simple answer. Like, which material makes the best 3D printed wrench? [My Tech Fun] printed a bunch of options to find out — including some expensive filaments — and got some interesting insights in the process.

His setup is simple: he printed a bunch of 13 mm open-end wrenches, and tested each one to failure by cranking on a clamped digital torque meter until the wrench failed by breaking, or skipping.

[My Tech Fun] tested a total of eighteen filaments, from regular basic PLA, PETG, ABS and ASA, and a variety of carbon fiber-infused filaments including PPA-CF. TPU is included for fun, and there’s also a wrench printed with continuous carbon fiber, which requires a special printer. More on that in a moment. First, let’s get to the results!
PETG wrench reinforced with continuous carbon fiber. The result is extremely stiff compared to without.
Unsurprisingly, TPU fared the worst at 0.8 nM which is roughly “unscrewing the cap of a water bottle” territory. Top performers included the wrench printed with continuous carbon fiber reinforcement (failing at 3.7 nM) and a couple printed in expensive PPA-CF (high-temperature nylon filament with carbon fiber) topped the list at 4.3 nM. Everything else landed somewhere in between, with plain PLA surprisingly outperforming some CF blends.

The continuous carbon fiber wrench was printed on a FibreSeeker printer, which reinforces a print with solid fibers embedded into the plastic instead of chopped particles, and such prints are noticeably more resistant to bending. Check out our earlier coverage for a closer look at what the FibreSeeker does.

This is a good time to mention that the wrench 3D model used is not at all optimized for best results with 3D printing. But that’s okay; this is really about the filaments, not the wrench.

The wrench model is just a way to test things in a familiar and highly visual, relatable way. You can see each one in action in the video below, and seeing [My Tech Fun] turn the wrenches gives a very good idea of just how much force is involved, with a relatable display of just how strong the different filaments are.

youtube.com/embed/b2a1h-bc2Zw?…

hackaday.com/2026/01/30/do-exp…

Another chilly evening in Western Europe, as Elliot Williams is joined this week by Jenny List to chew the fat over the week’s hacks.

It’s been an auspicious week for anniversaries, with the hundredth since the first demonstration of a working television system in a room above a London coffee shop. John Logie Baird’s mechanically-scanned TV may have ultimately been a dead-end superseded by the all-electronic systems we all know, but the importance of television for the later half of the 20th century and further is beyond question.

The standout hacks of the week include a very clever use of the ESP32’s WiFi API to detect people moving through a WiFi field, a promising open-source smartphone, another ESP32 project in a comms system for cyclists, more cycling on tensegrity spokes, a clever way to smooth plaster casts, and a light sculpture reflecting Wi-Fi traffic. Then there are a slew of hacks including 3D printed PCBs and gem-cut dichroic prisms, before we move to the can’t-miss articles. There we’re looking at document preservation, and a wallow in internet history with a look at the Netscape brand.

As usual all the links you need can be found below, so listen, and enjoy!

html5-player.libsyn.com/embed/…

Or download the podcast old-school, with a direct link to the MP3 file in question.

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

• iTunes
• Spotify
• Stitcher
• RSS
• YouTube
• Check out our Libsyn landing page

Episode 354 Show Notes:

What’s that Sound?

• Jenny got the sound right. Did you? Only one way to find out: put your handle and guess in here.

News

• One Hundred Years Of Telly
  
  • Mechanical Image Acquisition With A Nipkow Disc

  
  

Interesting Hacks of the Week:

• Make Your Own ESP32-Based Person Sensor, No Special Hardware Needed
  
  • espectre/micro-espectre at main · francescopace/espectre · GitHub
  • GitHub – francescopace/micropython-esp32-csi: MicroPython – a lean and efficient Python implementation for microcontrollers and constrained systems
  • Heart Rate Monitoring Via WiFi
  • Heart Rate Measurement Via WiFi, The DIY Way

  
  

• Pi Compute Module Powers Fully Open Smartphone
• These Ultra-Cute, Handsfree Walkie-Talkies Are Built For Cycling
• PLA Mold To Plaster Bust, No Silicone Needed
• Building A Light That Reacts To Radio Waves
• Bike Spokes, Made Of Rope
  
  • Gears Are Old And Busted, Capstans Are Cool
  • A Tentacle That’s A Work Of Art

  
  

Quick Hacks:

• Elliot’s Picks:
  
  • Using 3D Printing And Copper Tape To Make PCBs
  • X-Cube Prism Becomes Dichroic Disco Ball
  • Light Following Robot Does It The Analog Way

  
  

• Jenny’s Picks:
  
  • Post-rampocalyptic Chip-Swap Provides Desktop Memory At Laptop Prices
  • Wikipedia As A Storage Medium
  • The Defunct Scooter Company, And The Default Key

  
  

Can’t-Miss Articles:

• Ask Hackaday: How Do You Digitize Your Documents?
  
  • Gears Are Old And Busted, Capstans Are Cool
  • Page-turning Book Scanner Roundup
  • DIY Book Scanner Processes 600 Pages/hour

  
  

• Zombie Netscape Won’t Die

hackaday.com/2026/01/30/hackad…

[Androxilogin] had a problem. An Xbox 360 Slim had shown up in the post, but failed to give much more than a beep when turned on. Disassembly revealed some missing components, but replacing them failed to breathe life into the beleaguered console. Deeper repair was needed, and that would require a special adapter which [Androxilogin] was able to whip up from scratch.

When it comes to the Corona models of the Xbox 360, it’s often necessary to use something called a “post-fix adapter” to do certain diagnostic and repair tasks. These adapters consist of a bracket which wraps around the CPU, and probes the solder ball for the POST_OUT signal which is otherwise difficult to access on the motherboard itself. Adapters are readily available online, and are usually manufactured as a PCB with a protruding contact to make a connection.

For [Androxilogin], though, time was short. Rather than wait for adapters to ship, it was quicker to whip up a custom piece to do the same job. This was achieved with a 3D print which was able to clamp around the CPU, while snugly holding a piece of tinned 30 AWG wire to poke the critical point beneath the chip. After a couple of attempts to get the sizing just right, [Androxilogin] was able to make the necessary connection which enabled installing Xell Loader on to the machine to bring it back to life.

If you’re eager to make your own post-fix adapter, files are available on Printables, with more details over on Reddit to boot. While the Xbox 360 is starting to suffer some awkward symptoms of age. we nevertheless still see a steady stream of hacks come in for this vintage machine. If you’re tackling your own retro console mods, be sure to notify the tipsline.

hackaday.com/2026/01/30/whippi…

These days, the conversation around climate change so often focuses on matters of soaring temperatures and extreme weather events. While they no longer dominate the discourse, rising sea levels will nonetheless still be a major issue to face as global average temperatures continue to rise.

This poses unique challenges in coastal areas. Municipalities must figure out how to defend their shorelines, or decide which areas they’re willing to lose. The City of Palo Alto is facing just this challenge, and is building a natural kind of seawall to keep the rising tides at bay.

Seawalls That Breathe

The traditional way to fight back against the sea is with seawalls. These typically consist of steep slopes constructed on the shoreline, which are designed to reflect wave energy back to the sea and stop it from eating away at the land. They are normally built using rocks, steel, or concrete walls to dissipate the energy of incoming waves. They are typically simple to design and construct, and prove relatively effective at staving off erosion. However, they can also be quite imposing and unsightly, and often do very little to support native fauna and flora.
The horizontal levee design (left) compared to a traditional rock-based seawall (right). The latter is simpler and quicker to construct, but is far less visually appealing and does little to support the local ecosystem. Credit: City of Palo Alto
The City of Palo Alto is taking an altogether different approach by building a horizontal levee to protect the shore of Harbor Marsh. It eschews the usual steeply sloped seawall concept entirely. Instead, the coast is to be given a gentle gradient constructed of earth, creating a so-called “ecotone slope”—a long, sloping habitat down to the water line. Where the tide meets the shore, native plantings will support a tidal marsh, transitioning to a freshwater marsh with different plants farther up the slope, with volunteers planting 35 species in all. It’s hoped that restoring these habitats in the area will provide support to species like the Ridgway’s rail and the salt marsh harvest mouse.
Wastewater is used to support the growth of native plant species, helping to create the transition between the freshwater marsh and the tidal marsh along the “ecotone slope.” Credit: City of Palo Alto
Furthermore, from the top of the horizontal levee, wastewater will be fed in to support the growth of native plants, which will work with the soil to filter out pollutants as it makes its way to the sea in a process referred to as “polishing treatment”. It’s not intended to remove heavy pollutants from the water; this work is handled at existing municipal water treatment facilities. What the levee can handle is soaking up some of the nitrogen and phosphorous content to support plants on the slope. This reduces the amount of these nutrients that gets released out into the bay, which can cause fish die-offs, algal blooms, and other undesirable consequences.
Volunteers came together to plant native species on the horizontal levee. Construction is expected to be completed by summer this year. Credit: City of Palo Alto
Due to its limited size, the horizontal levee will only handle 100,000 gallons of wastewater per day, which isn’t much against the 20 million gallons that currently flows out into the bay. Ultimately, that’s because the work at Harbor Marsh is a pilot project for the City of Palo Alto. Ideally, it will prove effective in both limiting coastal erosion as well as supporting native plants and animals. If it proves successful, it could become a strategy used elsewhere along the San Francisco coastline and beyond. The Bay Area as a whole needs to be protected against rising sea levels, as the name implies, so projects like this are a key focus as authorities plan for the future.

As it stands, large artificial seawalls probably aren’t going anywhere. It’s very straightforward to build massive concrete and steel structures to defend a piece of coastline. The engineering involved is well understood, and the construction process does not require particular finesse in the selection of plants or the maintenance of native habitats. However, in areas where it’s desirable to slow erosion in a greener fashion, horizontal levees could become popular. After all, it’s a lot nicer to stroll on a path alongside a burgeoning native marshland than it is to feel the sun bouncing off acres of harsh concrete. If the Harbor Marsh experiment works, expect to see similar projects take off in coastal areas around the world.

hackaday.com/2026/01/30/buildi…