A security breach tied to decentralized exchange aggregator Matcha Meta has resulted in the theft of roughly $16.8 million in crypto assets, adding to a growing list of smart-contract exploits that continue to test the safety assumptions of DeFi users.

The incident unfolded on Sunday and was traced not to Matcha’s core infrastructure, but to SwapNet, one of the liquidity providers integrated into the platform.

Matcha Meta disclosed the issue publicly in a post on X, saying users who had disabled its “One-Time Approval” feature and instead granted direct token allowances to individual aggregator contracts may have been exposed.

We are aware of an incident with SwapNet that users may have been exposed to on Matcha Meta for those who turned off One-Time Approvals

We are in contact with the SwapNet team and they have temporarily disabled their contracts

The team is actively investigating and will provide…

— Matcha Meta (@matchametaxyz) January 25, 2026

The protocol urged affected users to immediately revoke approvals connected to SwapNet’s router contract, warning that failure to do so could leave wallets vulnerable to further unauthorized transfers.

$17M Vanishes in Seconds: How Matcha Hackers Slipped Funds Onto Ethereum

Blockchain security firms quickly began tracking the exploit as funds moved on-chain.

PeckShield reported that approximately $16.8 million had been drained in total, with the attacker swapping around $10.5 million in USDC for roughly 3,655 ETH on the Base network before starting to bridge assets to Ethereum.

#PeckShieldAlert Matcha Meta has reported a security breach involving SwapNet. Users who opted out of "One-Time Approvals" are at risk.

So far, ~$16.8M worth of crypto has been drained.

On #Base, the attacker swapped ~10.5M $USDC for ~3,655 $ETH and has begun bridging funds to… https://t.co/QOyV4IU3P3 pic.twitter.com/6OOJd9cvyF

— PeckShieldAlert (@PeckShieldAlert) January 26, 2026

CertiK independently flagged suspicious transactions, identifying one wallet that siphoned about $13.3 million in USDC on Base and converted the funds into wrapped Ether.

Both firms pointed to a vulnerability in the SwapNet contract that allowed arbitrary calls, enabling the attacker to transfer tokens that users had previously approved.

1/ The vulnerability seems to be in arbitrary call in @0xswapnet contract that let attacker to transfer funds approved to it. (https://t.co/B7ux5zzMLS)

The team have temporarily disabled their contracts is actively investigating.https://t.co/NBNvzxHCRw

Please revoke approval…

— CertiK Alert (@CertiKAlert) January 26, 2026

Matcha later clarified that the incident was not connected to 0x’s AllowanceHolder or Settler contracts, which underpin its One-Time Approval system.

The team noted that users who interacted with Matcha using One-Time Approvals were not affected, as this design limits how much access a third-party contract can retain.

After reviewing with 0x's protocol team, we have confirmed that the nature of the incident was not associated with 0x's AllowanceHolder or Settler contracts.

Users who have interacted with Matcha Meta via One-Time Approval are thus safe.

Users who have disabled One-Time… https://t.co/VQVmj4LL0F

— Matcha Meta (@matchametaxyz) January 25, 2026

The exposure, the team said, applied only to users who opted out of that system and granted ongoing allowances directly to aggregator contracts. In response, Matcha has removed the option for users to set such direct approvals going forward.

Old Token Approvals Emerge as a Persistent DeFi Weak Spot

The breach highlights a recurring tension in DeFi between flexibility and safety. Token approvals, while necessary for interacting with smart contracts, have long been a weak point, particularly when permissions remain active long after a transaction is completed.

In this case, previously granted allowances became the pathway for the exploit once the SwapNet contract was compromised.

The incident arrives amid continued concerns over smart-contract security across the crypto sector.

SlowMist’s year-end report shows that vulnerabilities in smart contracts accounted for just over 30% of crypto exploits in 2025, making them the leading cause of losses.

Researchers have also warned that advances in artificial intelligence are accelerating how quickly attackers can identify and exploit weaknesses in on-chain code.

While overall crypto losses declined in December, falling about 60% month-on-month to roughly $76 million, security firms cautioned that the drop did not reflect a structural improvement.

Crypto-related losses from hacks and cybersecurity exploits fell sharply in December, dropping 60% month-on-month to about $76 million.#Crypto #Hackhttps://t.co/mke6K8sLVQ

— Cryptonews.com (@cryptonews) January 2, 2026

PeckShield noted that a single address-poisoning scam accounted for $50 million of December’s losses, showing how concentrated and severe individual incidents can be even during quieter periods.

January has already seen several notable exploits. IPOR Labs confirmed a $336,000 attack on its USDC Fusion Optimizer vault on Arbitrum, while Truebit disclosed a smart-contract incident that on-chain analysts estimate drained more than 8,500 ETH, triggering a near-total collapse in the project’s token price.

Last week, Layer-1 network Saga paused its SagaEVM chain after an exploit moved close to $7 million in assets to Ethereum.

The post Matcha Meta Breach Drains $16.8M via SwapNet Exploit — Users Urged to Revoke Access appeared first on Cryptonews.

[Bhaskar Das] has been tinkering with one of Nintendo’s more obscure handhelds, the DSi. The old-school console has been given a new job as part of an augmented reality app called AetherShell. 

The concept is straightforward enough. The Nintendo DSi runs a small homebrew app which lets you use the stylus to make simple line drawings on the lower touchscreen. These drawings are then trucked out wirelessly as raw touch data via UDP packets, and fed into a Gemini tool which transforms them into animation frames. These are then sent to an iPhone app, which uses ARKit APIs and the phone’s camera to display the animations embedded into the surrounding environment via augmented reality.

One might question the utility of this project, given that the iPhone itself has a touch screen you can draw on, too. It’s a fair question, and one without a real answer, beyond the fact that sometimes it’s really fun to play with an old console and do weird things with it. Plus, there just isn’t enough DSi homebrew out in the world. We love to see more.

We know this one is a few years old, but unless you’re deep into the cycling scene, there’s a good chance this is the first time you’ve heard of [Ali Clarkson’s] foray into home made rope spokes. 

The journey to home-made rope spoke begun all the way back in 2018, shortly after the company Berd introduced their very expensive rope spokes. Berd’s spokes are made of a hollow weaved ultrahigh molecular weight polyethylene (UHMWPE) rope with very low creep. They claim wheels stronger than steel spoke equivalents at a fraction of the weight. Naturally forum users asked themselves, “well why can’t we make our own?” As it turns out, there are a handful of problems with trying this at home.

There are a number of ways to skin this proverbial cat, but they all center around some very special nautical ropes, namely, Robline DM20. This rope has excellent wear and creep characteristics, in a hollow weave much like what Berd developed. The hubs also require the addition of a bevel around the spoke holes to prevent wear. Beyond those two similarities, there are quite a number of ways to lace the spokes between the hub and wheels.

As detailed by [Ali Clarkson], one method involves creating loops out of bike spokes, with a custom jig and some brazing. Then a length of rope is passed through the hub and a special hitch is used to keep it in place. Two loops are made in the ends of this length of rope and passed through the spoke ends made earlier. Finally everything is brought up to tension and trued much like a normal wheelset. The front wheel ended up weighing around 700g, a rather impressive feat for a 24 inch downhill wheel.

However, a number of other methods have been tried on the forum threads. Namely, a number of users have attempted to varying degrees of success putting a length of spoke inside the hollow rope weave and “Chinese finger trapping” it together. The key issue here is sourcing a glue strong enough to hold the spoke piece on at lower tensions, but flexible enough to not crack with the cyclical loading on a rim.

Ultimately, this is a great look at the properties of some extremely special rope. This also isn’t the first time we have seen strange bicycle wheels made with UHMWPE.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It’s fair to say that there are many people in our community who just love to dunk on Microsoft Windows. It’s an easy win, after all, the dominant player in the PC operating system market has a long history of dunking on free software, and let’s face it, today’s Windows doesn’t offer a good experience. But what might the future hold? [Mason] has an unexpected prediction: that Microsoft will eventually move towards offering a Windows-themed Linux distro instead of a descendant of today’s Windows.

The very idea is sure to cause mirth, but on a little sober reflection, it’s not such a crazy one. Windows 11 is slow and unfriendly, and increasingly it’s losing the position once enjoyed by its ancestors. The desktop (or laptop) PC is no longer the default computing experience, and what to do about that must be a big headache for the Redmond company. Even gaming, once a stronghold for Windows, is being lost to competitors such as Valve’s Steam OS, so it wouldn’t be outlandish for them to wonder whether the old embrace-and-extend strategy could be tried on the Linux desktop.

We do not possess a working crystal ball here at Hackaday, so we’ll hold off hailing a Microsoft desktop Linux. But we have to admit it’s not an impossible future, having seen Apple reinvent their OS in the past using BSD, and even Microsoft bring out a cloud Linux distro. If you can’t wait, you’ll have to make do with a Windows skin, WINE, and the .NET runtime on your current Linux box.

Robots don’t have to be large and imposing to be impressive. As this tiny quadruped from [Dorian Todd] demonstrates, some simple electronics and a few servos can create something altogether charming on their own.

This little fellow is named Sesame. A quadruped robot, it’s built out of 3D-printed components. Each leg features a pair of MG90S hobby servos, one of which rotates the leg around the vertical axis, while the other moves the foot. The ESP32 microcontroller controls all eight servos, enabling remote control of Sesame via its built-in wireless connectivity. Sesame also gets a 128×64 OLED display, which it uses to display a range of emotions.

Mechanically, the Sesame design isn’t particularly sophisticated. Where it shines is that even with such a limited range of motion, between its four legs and its little screen, this robot can display a great deal of emotion. [Dorian] shows this off in the project video, in which Sesame scampers around a desktop with all the joy and verve of a new puppy. It’s also very cheap; [Dorian] estimates you can build your own Sesame for about $60. Files are on GitHub for the curious.

If you prefer your quadrupeds built for performance over charm, you might consider an alternative build. Video after the break.

For certain high-security devices, such as card readers, ATMs, and hardware security modules, normal physical security isn’t enough – they need to wipe out their sensitive data if someone starts drilling through the case. Such devices, therefore, often integrate circuit meshes into their cases and regularly monitor them for changes that could indicate damage. To improve the sensitivity and accuracy of such countermeasures, [Jan Sebastian Götte] and [Björn Scheuermann] recently designed a time-domain reflectometer to monitor meshes (pre-print paper).

Many meshes are made from flexible circuit boards with winding traces built into the case, so cutting or drilling into the case breaks a trace. The problem is that most common ways to detect broken traces, such as by resistance or capacitance measurements, aren’t easy to implement with both high sensitivity and low error rates. Instead, this system uses time-domain reflectometry: it sends a sharp pulse into the mesh, then times the returning echoes to create a mesh fingerprint. When the circuit is damaged, it creates an additional echo, which is detected by classifier software. If enough subsequent measurements find a significant fingerprint change, it triggers a data wipe.

The most novel aspect of this design is its affordability. An STM32G4-series microcontroller manages the timing, pulse generation, and measurement, thanks to its two fast ADCs and a high-resolution timer with sub-200 picosecond resolution. For a pulse-shaping amplifier, [Jan] and [Björn] used the high-speed amplifiers in an HDMI redriver chip, which would normally compensate for cable and connector losses. Despite its inexpensive design, the circuit was sensitive enough to detect when oscilloscope probes contacted the trace, pick up temperature changes, and even discern the tiny variations between different copies of the same mesh.

It’s not absolutely impossible for an attacker to bypass this system, nor was it intended to be, but overcoming it would take a great deal of skill and some custom equipment, such as a non-conductive drill bit. If you’re interested in seeing such a system in the real world, check out this teardown of a payment terminal. One of the same authors also previously wrote a KiCad plugin to generate anti-tamper meshes.

Thanks to [mark999] for the tip!

We live in a golden age for MIDI controllers. [rheslip]’s contribution to the milieu is a twisty take on the format, in that it’s covered in an array of knobs. Thus the name—Twisty 2. 

The controller can be built using the Raspberry Pi Pico or Pico 2. It’s set up to read a 4×4 array of clickable encoders, plus two bonus control knobs to make 18 in total, which are read via a 74HC4067 analog mux chip. There’s also an SK6812 RGB LED for each encoder, and an OLED display for showing status information. MIDI output is via USB, or, if you purchased the W variant of the Pi Pico/Pico 2, it can operate wirelessly over Bluetooth MIDI instead. The controller is set up to send MIDI CC messages, program changes, or note on/off messages depending on its configuration. Flipping through different modes is handled with the bottom set of encoders and the OLED display.

Few musicians we’ve ever met have told us they learned how to play the encoders, and yet. The cool thing about building your own MIDI controller is you can tune it to suit whatever method of performance strikes your fancy. If the name of this build alone has you inspired, you could always whip up a MIDI controller out of a Twister mat.

Attributed to Picasso was the notion that when art critics get together they talk about content, style, trend, and meaning; but that when painters get together they talk about where to get the best turpentine. We can extend that sentiment into the digital age by saying that when philosophers get together they talk about ideas, theory, and meaning; but when hackers get together they talk about where to get the best tweezers.

In this video [nanofix] runs us through his collection of tweezers talking about what he likes and doesn’t like for each. If you’re just getting into microsoldering this video will have some tips about where you should start, and if you’ve been soldering tiny stuff for a while you might find some ideas for a helpful new bit of kit, or two.

If you’re interested in tweezers and novel applications you might want to check out “smart” tweezers, which can read capacitance and resistance values on the fly. Or read about a suction based SMD tool, which can securely hold SMD components with less risk of them flying across the bench and disappearing forever into the carpet on the floor.

Al and I were talking about the IBM 9020 FAA Air Traffic Control computer system on the podcast. It’s a strange machine, made up of a bunch of IBM System 360 mainframes connected together to a common memory unit, with all sorts of custom peripherals to support keeping track of airplanes in the sky. Absolutely go read the in-depth article on that machine if it sparks your curiosity.

It got me thinking about how strange computers were in the early days, and how boringly similar they’ve all become. Just looking at the word sizes of old machines is a great example. Over the last, say, 40 years, things that do computing have had 4, 8, 16, 32, or even 64-bit words. You noticed the powers-of-two trend going on here, right? Basically starting with the lowly Intel 4004, it’s been round numbers ever since.

On the other side of the timeline, though, you get strange beasts. The classic PDP-8 had 12-bit words, while its predecessors the PDP-6 and PDP-1 had 36 bits and 18 bits respectively. (Factors of six?) There’s a string of military guidance computers that had 27-bit words, while the Apollo Guidance computer ran 15-bit words. UNIVAC III had 25-bit words, putting the 23-bit Harvard Mark I to shame.

I wasn’t there, but it gives you the feeling that each computer is a unique, almost hand-crafted machine. Some must have made their odd architectural choices to suit particular functions, others because some designer had a clever idea. I’m not a computer historian, but I’m sure that the word lengths must tell a number of interesting stories.

On the whole, though, it gives the impression of a time when each computer was it’s own unique machine, before the convergence of everything to roughly the same architectural ideas. A much more hackery time, for lack of a better word. We still see echoes of this in the people who make their own “retro” computers these days, either virtually, on a breadboard, or emulated in the fabric of an FPGA. It’s not just nostalgia, though, but a return to a time when there was more creative freedom: a time before 64 bits took over.

Plus: The FAA blocks drones over DHS operations, Microsoft admits it hands over Bitlocker encryption keys to the cops, and more.

When you’re testing or debugging some mains-powered gear, plugging it directly into the outlet can often be an exciting proposition. If such excitement is not really your thing, you can opt for an isolation transformer and other types of safeties. In the case of [Michał Słomkowski], he opted to take a few steps further by modding a vintage East-German isolating variac with a broken amp meter into an isolated AC/DC power supply and testing station.

The core is formed by the isolated variable transformer, to which a configurable DC output section, a current limiter and digital voltage and current read-outs were added. This enables a variable AC output of 0 – 330 VAC and 0 – 450 VDC on their respective terminals, with the incandescent light bulb providing an optional current limiter.

In its final configuration [Michał] has been using the device for the past four years now for a range of tasks, including the simulating of various undesirable mains power conditions, varying the speed of an old Soviet-era drill, powering vacuum tube devices, capacitor reforming and of course running 100-120 VAC devices from e.g. the US.

As far as feature set goes, we have to admit that it is an impressive device, indeed. Although some parts of it are clearly playing it fast and loose with best practices, with [Michał] admitting to not being an electrician, it was clearly engineered well enough to survive a few years of use, something which cannot be said for even professional laboratory equipment these days.

When you think of a high performance liquid rocket, what do you think of? Beer kegs? No? Well, when [Ryan] from the YouTube channel “Project KegRocket” saw a beer keg, the first thing he and his friends saw was a pressurized rocket body.

You wouldn’t be crazy if the first thing you thought of was something designed by a massive company or university. Liquid rockets are far from simple to develop, with Keg Rocket being no exception. Liquid oxygen and alcohol is the oxidizer/fuel mixture of choice. Liquid oxygen in particular is a problem with its cryogenic temperatures and tendency to do what rocket fuel does best, burn. This problem causes a large amount of work to simply connect the pipes. Traditional O-rings have no chance at surviving, along with most other non-metallic solutions.

Even with all these problems, the group creating the piece of art is more than capable, having experience creating similar rockets in the past. As of currently, the pumping has been pressure and leak checked. We will be watching this project closely for updates and an eventual launch.

For more rocketry science, be sure to check out aerospike engines for the most efficient engines around. If you want efficiency in your pizzas and beer kegs, check out this keg pizza oven instead!

Lithium batteries have taken over as the primary battery chemistry from applications ranging from consumer electronics to electric vehicles and all kinds of other things in between. But the standard lithium ion battery has a few downsides, namely issues operating at temperature extremes. Lead acid solves some of these problems but has much lower energy density, and if you want to split the difference with your own battery you’ll need to build your own lithium iron phosphate (LiFePO4) pack.

[Well Done Tips] is building this specific type of battery because the lead acid battery in his electric ATV is on the decline. He’s using cylindrical cells that resemble an 18650 battery but are much larger. Beyond the size, though, many of the design principles from building 18650 battery packs are similar, with the exception that these have screw terminals so that bus bars can be easily attached and don’t require spot welding.

With the pack assembled using 3D printed parts, a battery management system is installed with the balance wires cleverly routed through the prints and attached to the bus bars. The only problem [Well Done Tips] had was not realizing that LiFePO4 batteries’ voltages settle a bit after being fully charged, which meant that he didn’t properly calculate the final voltage of his pack and had to add a cell, bringing his original 15S1P battery up to 16S1P and the correct 54V at full charge.

LiFePO4 has a few other upsides compared to lithium ion as well, including that it delivers almost full power until it’s at about 20% charge. It’s not quite as energy dense but compared to the lead-acid battery he was using is a huge improvement, and is one of the reasons we’ve seen them taking over various other EV conversions as well.

3D printing is wonderful, but sometimes you just don’t want to look at a plastic peice. Beethoven’s bust wouldn’t look quite right in front of your secret door if it was bright orange PLA, after all. [Denny] over at “Shake the Future” on YouTube is taking a break from metal casting to show off a quick-and-easy plaster casting method— but don’t worry, he still uses a microwave.

Most people, when they’re casting something non-metallic from a 3D print are going to reach for castable silicone and create a mold, first. It works for chocolate just as easily as it does plaster, and it does work well. The problem is that it’s an extra step and extra materials, and who can afford the time and money that takes these days?

[Denny]’s proposal is simple: make the mold out of PLA. He’s using a resin slicer to get the negative shape for the mold, and exporting the STL to slice in PrusaSlicer, but Blender, Meshmixer and we’re pretty sure Cura should all work as well. [Denny] takes care when arranging his print to avoid needing supports inside the mold, but that’s not strictly necessary as long as you’re willing to clean them out. After that, it’s just a matter of mixing up the plaster, pouring it into the PLA, mold, and waiting.

Waiting, but not too long. Rather than let the plaster fully set up, [Denny] only waits about an hour. The mold is still quite ‘wet’ at this point, but that’s a good thing. When [Denny] tosses it in his beloved microwave, the moisture remaining in the plaster gets everything hot, softening the PLA so it can be easily cut with scissors and peeled off.

Yeah, this technique is single-use as presented, which might be one advantage to silicone, if you need multiple copies of a cast. Reusing silicone molds is often doable with a little forethought. On the other hand, by removing the plaster half-cured, smoothing out layer lines becomes a simple matter of buffing with a wet rag, which is certainly an advantage to this technique.

Some of you may be going “well, duh,” so check out [Denny]’s cast-iron benchy if his plasterwork doesn’t impress. We’ve long been impressed with the microwave crucibles shown off on “Shake the Future”, but it’s great to have options. Maybe metal is the material, or perhaps plain plastic is perfect– but if not, perchance Plaster of Paris can play a part in your play.

Few things rival the usability and speed of a full-sized keyboard for text input. For decades, though, keyboards were mostly wired, which can limit where you use your favorite one. To address this, [KoStard]’s latest project uses an ESP32 to bridge a USB keyboard to BLE devices.

The ESP32-S3 packs a ton of fantastic functionality into its small size and low price—including USB-OTG support, which is key here. Taking advantage of this, [KoStard] programmed an ESP32-S3 to host a keyboard over its USB port while connecting via BLE to devices like cellphones.

There are some slick tricks baked in, too: you can pair with up to three devices and switch between them using a key combo. Some of you might be wondering how you can just plug a microcontroller into a keyboard and have it work. The truth is, it doesn’t without extra hardware. Both the keyboard and ESP32-S3 need power. The simplest fix is a powered USB hub: it can be battery-powered for a truly mobile setup, or use a wired 5V supply so you never have to charge batteries.

We love seeing a simple, affordable microcontroller extend the usefulness of gear you already have. Let us know in the comments about other hacks you’ve used to connect keyboards to devices never designed for them.

Today’s PCs are locked up with Trusted Platform Module (TPM) devices so much so that modern Windows versions insist on having a recent TPM to even install. These have become so prevalent that even larger embedded boards now have TPM and, of course, if you are repurposing consumer hardware, you’ll have to deal with it, too. [Sigma Star] has just the primer for you. It explains what TPM does, how it applies to embedded devices, and where the pitfalls are.

The TPM is sometimes a chip or sometimes secure firmware that is difficult to tamper with. They provide secret storage and can store boot signatures to detect if something has changed how a computer starts up. The TPM can also “sign off” that the system configuration is the same to a remote entity. This allows, for example, a network to prevent a hacked or rogue computer from communicating with other computers.

Embedded systems, usually, aren’t like PCs. A weather station at a remote location may have strangers poking at it without anyone noticing. Also, that remote computer might be expected to be working for many more years than a typical laptop or desktop computer.

This leads to a variety of security concerns that TPM 2.0 attempts to mitigate. For example, it is unreasonable to think a typical attacker might connect a logic analyzer to your PC, but for an embedded system, it is easier to imagine. There is a session-based encryption to protect against someone simply snooping traffic off the communication bus. According to the post, not all implementations use this encryption, however.

Motherboard has a slot for TPM, but no board? We’ve seen people build their own TPM boards.

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Title image by [Raimond Spekking] CC BY-SA-4.0

This “dream wish list for criminals” includes millions of Gmail, Facebook, banking logins, and more. The researcher who discovered it suspects they were collected using infostealing malware.

Over on YouTube [Nic Barker] gives us: UTF-8, Explained Simply.

If you’re gonna be a hacker eventually you’re gonna have to write software to process and generate text data. And when you deal with text data, in this day and age, there are really only two main things you need to know: 7-bit ASCII and UTF-8. In this video [Nic] explains 7-bit ASCII and Unicode, and then explains UTF-8 and how it relates to Unicode and ASCII. [Nic] goes into detail about some of the clever features of Unicode and UTF-8 such as self-synchronization, single-byte ASCII, multi-byte codepoints, leading bytes, continuation bytes, and grapheme clusters.

[Nic] mentions about UTF-16, but UTF-16 turned out to be a really bad idea. UTF-16 combines all of the disadvantages of UTF-8 with all of the disadvantages of UTF-32. In UTF-16 there are things known as “surrogate pairs”, which means a single Unicode codepoint might require two UTF-16 “characters” to describe it. Also the Byte Order Marks (BOM) introduced with UTF-16 proved to be problematic. Particularly if you cat files together you can end up with stray BOM indicators randomly embedded in your new file. They say that null was a billion dollar mistake, well, UTF-16 was the other billion dollar mistake.

tl;dr: don’t use UTF-16, but do use 7-bit ASCII and UTF-8.

Oh, and as we’re here, and talking about Unicode, did you know that you can support The Unicode Consortium with Unicode Adopt-a-Character? You send money to sponsor a character and they put your name up in lights! Win, win! (We noticed while doing the research for this post that Jeroen Frijters of IKVM fame has sponsored #, a nod to C#.)

If you’re interested in learning more about Unicode check out Understanding And Using Unicode and Building Up Unicode Characters One Bit At A Time.

It’s possible to improve your 3D prints in all kinds of ways. You can tune your printer’s motion, buy better filament, or tinker endlessly with any number of slicer settings. Or, as [Dirt-E-Bikes] explains, you could grab yourself some silica gel.

If you’re unfamiliar with silica gel, it’s that stuff that comes in the “DO NOT EAT” packet when you buy a new pair of shoes. It’s key feature is that it’s hygroscopic—which means it likes to suck up moisture from the atmosphere. When it comes to 3D printing, this is a highly useful property—specifically because it can help keep filament dry. Over time, plastic filament tends to pick up some moisture on its own from the atmosphere, and this tends to interfere with print quality. This can be avoided by storing filament in a sealed or semi-seaeled environment with silica gel. The gel will tend to suck up most of the moisture from the air in the sealed container, helping to keep the filament drier.

[Dirt-E-Bikes] does a great job of explaining how best to integrate silica gel with your filament spools and automatic material changer (if you have one). He also explains the value of color changing silica gel which indicates when the material is saturated with water, as well as how to dry it out for reuse. You can even combine some of the color changing beads with the more common plain white beads recycled from your shoe boxes, since you only need a few colored beads to get an idea of the water content.

We’ve explored other filament drying solutions before, too. Video after the break.

[Thanks to Keith Olson for the tip!]

After the swivel by Helium Inc. towards simply running distributed WiFi hotspots after for years pushing LoRaWAN nodes, much of the associated hardware became effectively obsolete. This led to quite a few of these Nebra LoRa Miners getting sold off, with the [Buy it Fix it] channel being one of those who sought to give these chunks of IP-67-rated computing hardware a new life.

Originally designed to be part of the Helium Network Token (HNT) cryptocurrency mining operation, with users getting rewarded by having these devices operating, they contain fairly off-the-shelf hardware. As can be glanced from e.g. the Sparkfun product page, it’s basically a Raspberry Pi Compute Module 3+ on a breakout board with a RAK 2287 LoRa module. The idea in the video was to convert it into a Meshcore repeater, which ought to be fairly straightforward, one might think.

Unfortunately the unit came with a dead eMMC chip on the compute module, the LoRa module wasn’t compatible with Meshcore, and the Nebra breakout board only covers the first 24 pins of the standard RPi header on its pin header.

The solutions involved using a µSD card for the firmware instead of the eMMC, and doing some creative routing on the bottom of the breakout board to connect the unconnected pins on the breakout’s RPi header to the pins on the compute module’s connector. This way a compatible LoRa module could be placed on this header.

Rather than buying an off-the-shelf LoRa module for the RPi and waiting for delivery, a custom module was assembled from an eByte E22 LoRa module and some stripboard to test whether the contraption would work at all. Fortunately a test of the system as a Meshcore repeater showed that it works as intended, serving as a pretty decent proof-of-concept of how to repurpose those systems from a defunct crypto mining scheme into a typical LoRa repeater, whether Meshcore or equivalent.