Sheety Turns Spreadsheets Into Binaries, For Some Reason

September 30, 2026 by 8 Comments

Ever wanted a spreadsheet as an executable with a built-in terminal interface? No? Well, that’s a pity because [Roberto Alsina]’s Sheety project does exactly that.

Sheety compiles spreadsheet definitions into a self-contained, executable binary with zero runtime dependencies. It presents a simple terminal application (with mouse support) in which one can browse and edit data and formulas with a simple interface. As far as formats go it can import and export Excel files, or a human-readable .yaml file.

When Sheety runs, the data and formulas defined are compiled into a self-contained executable with the formulas baked in, and that’s actually what one sees and uses. If a formula gets changed in the UI, a new and updated version is created on the fly to reflect the changes.

Sheety is perfectly functional, though it does have some limitations. Can the display width of cells be resized? They cannot. Does anyone actually need this? Probably not, as [Roberto] happily admits. Is it a fun project? Absolutely.

Be warned that while Sheety supports the Excel format, it understandably doesn’t support every single function Excel has added in the over forty years it has been around.

Sheety is written in Crystal and the GitHub repository has everything you need if you’d like to give it a try for yourself.

A drawing of a battery cell with gunk on the labeled anode and cathode called the "thick and inactive interphase layer." An icon of a dead battery with two red bars within a pictograph of a battery is superimposed. An arrow points to the right to a cleaner looking cell with a full battery icon with green bars inside showing the cell after regeneration.

A Simple Solution For Streamlining Battery Recycling

September 30, 2026 by No comments

Lithium batteries have become the backbone of many modern devices ranging from toothbrushes to semi trucks, so what are we going to do with them when these rechargeable cells finally die? Researchers at Cornell have identified a way to streamline the recycling process.

Most current lithium battery recycling involves grinding up the batteries and separating active material from other components like the casing, current collectors, etc. These materials are then processed and turned back into fresh material for a new batch of batteries. Taking everything all the way down to rebuild it is time and labor consuming, and therefore expensive, especially in light of increasingly lower prices for lithium.

The researchers found that by electrochemically dissolving the inactive electrode–electrolyte interphase layers that built up over time, they could rejuvenate the electrode without completely taking it apart. This direct electrode-to-electrode regeneration (DEER) uses 1,3-dimethyl-2-imidazolidinone (DMI) as a solvent for the process. Once reassembled, these regenerated cells have up to 95% of their original capacity while cutting the cost of recycling by over half.

If you’re looking to reuse a pack before sending it to the recycler, may we suggest a whole house battery from an old EV pack and how to integrate them safely.

No More Windows For The Dutch Government, Ze Kiezen Nu Linux

September 29, 2026 by 28 Comments

The events of the last few years have caused many in Europe to re-evaluate their reliance on large offshore technology companies, with a corresponding move to home-grown EU-based alternatives. It’s one thing when individuals or companies do this, but another entirely when it’s an entire country. So the news that the Netherlands is building their own Linux distribution to replace Microsoft Windows in government installations, is not inconsequential. The Tweakers site linked  actively breaks out of Google Translate, so you may have to rely on your browser’s translation tool if you are not a Dutch speaker.

The Digitaal Autonome Werkomgeving Overheid, or Digital Autonomous Work Environment, is a distro based upon NixOS, itself originally a product of a Dutch university. It comes complete with all the office and collaboration applications needed to replace Windows, and is reported to have been tested already by a small group of Dutch government workers.

The influence of this move is likely to be a huge one for Microsoft, given that governments have huge numbers of operating system seats. But perhaps more important than the OS itself are the extras that Microsoft would like to sell to its OS customers, such as AI services. We’d expect that there will be managers in Redmond paying close attention to Europe in the wake of this move.

Meanwhile the Netherlands has a vibrant hacker community, and we can imagine that this move will be welcomed in those quarters. All Netherlands government online services are accessed through an ID verification app called DigID, and it’s a lament we’ve heard from our Dutch friends that this only works with Windows, Android and Apple platforms. If this means a Linux version will appear on the back of an NL government Linux distro, we know some people who will be very happy indeed.

NL flag: SpinnerLaserzthe2nd, CC0. Tux: Larry Ewing (lewing@isc.tamu.edu) and The GIMP. Attribution.

Determining Diamond’s Properties Under Extreme Pressures

September 29, 2026 by 1 Comment

Although graphene gives diamond a solid run for its money when it comes to being the most useful assembly of carbon atoms, both have the distinct property of material scientists still trying to figure out all their properties and potential applications. This includes something like the melting curve of diamond and potential phases beyond this diamond lattice phase that occur when exposed to extreme pressures and temperatures. Such as those experienced on a planetary scale and during inertial confinement fusion (ICF).

In this research (paywalled) by researchers at the Lawrence Livermore National Laboratory (LLNL), it was investigated how close theoretical simulations were to physical reality by blasting diamond samples with a laser. This ablated the surface and sent a shockwave through the material that caused it to melt. Using X-ray diffraction data this entire process was followed, elucidating the exact melting temperature under such conditions.

This revealed that previous estimates based on earlier experiments had been off by many hundreds of degrees, giving a far better idea of how diamond responds to such extreme pressures and temperatures. Where such information is very relevant is in fields like planetary science where diamonds can occur naturally and being able to predict their presence can be essential.

The other application, and the primary reason why LLNL does this kind of research is for the sake of ICF at the national ignition facility (NIF), which is the best way to investigate the behavior of e.g. hydrogen isotopes under extreme conditions like those of nuclear weapons.

Unfortunately this research will have no impact on practical power generation using nuclear fusion, as the only viable path there involves forms of magnetic confinement fusion (MCF), but it’s still pretty rad to improve our understanding this carbon form.

The Deep Magic Of 3D Graphics Perspective

September 29, 2026 by 5 Comments

Many of us of a certain age will have had their first true, good 3D video game experience with Super Mario 64. Unlike previous 3D games, the camera was an object controllable by the player, rather than a first-person-ony mode or one where the game tries to guess the best placement for the camera. We might take this mechanic for granted today, but 3D was a new technology at the time that took experimentation before settling on the norms we have today. From a programming perspective, 3D graphics can be a bit of a head-scratcher but [Gabriel] shows that perspective and the camera can be as simple as a few lines of math.

When starting out as a programmer, [Gabriel] used various tools that provided a camera somewhat automatically. But after reaching the limits of these types of frameworks, the next step is to learn how that works from scratch. It turns out that it’s a bit of matrix math, with values for foreground and background clipping planes as well as aspect, field of view, and position. This basically replicates a trapezoidal prism which can be thought of as a viewer looking at a scene from the perspective of a camera. To provide the depth effect, the X and Y coordinates are divided by the Z coordinate within this matrix system, making far-away objects smaller and generating the 3D effect.

On [Gabriel]’s site which explains this method, there are a few sliders in several examples that demonstrate how changing values of each of these variables changes the perspective and the object being displayed. For a math lesson it is very interactive and helps intuit these concepts. Cameras aside, the generation of 3D objects has its own unique set of math equations to learn about that are “equally” interesting.

Designing A Fully 3D-Printed Mechanical Calculator

September 29, 2026 by 7 Comments

Even if almost tragically impractical in a world where digital calculators are cheap as chips, mechanical calculators and their big mechanical computer brethren remain an absolute marvel of engineering. Using nothing but elements like simple gears their motion is used to calculate everything from a simple multiplication to the proper targeting instructions for an Iowa-class battleship’s guns.

This fascination, along with the mind-bendingly high prices for commercial digital calculators led [3D all Workshop] to spend 2 months on designing his own mechanical calculator. Fully FDM 3D-printed, of course.

In the video the design process and troubleshooting step are covered along with the workings of the mechanisms for both addition and multiplication. While this may seem simple, basically converting numbers of rotations into a final indicator position, aspects like carrying a digit and adding a multiplication feature to the mechanism require some proper engineering.

Of course, using FDM printing for tolerance-sensitive things like gears meant that a lot of time was spent redesigning aspects of the mechanism, going through about a hundred design iterations until it worked, with the help from a bit of lubrication.

Naturally this isn’t the first 3D-printed mechanical calculator, not to mention ones made from wood, but always it’s pretty cool to see one made from first fundamentals.

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Improved Double-Sided Toner Transfer Method

September 29, 2026 by 24 Comments

In the era before PCB shops would make almost any PCB imaginable, as well making many other manufacturing processes for prototypes available to hobbyists, there were several ways of making PCBs at home. Many of which involve harsh chemicals and were easy to mess up. Getting a single-layer PCB using the toner transfer method, for example, took a bit of practice (and a fume hood) to get right. [Bettina Neumryr] is working on a custom two-layer PCB, and has a new trick to get it to come out right despite the added complexity of the second layer.

The method starts out as a standard single-layer board in effect. Toner is ironed onto a copper board, in this case using a laminator, which allows the board to go into an acid bath which washes away all of the un-tonered copper. But with the second layer exposed, this would wash away the other side of the board completely. [Bettina] is using a new method here to protect that layer during the first bath: covering it in ink from a magic marker. With the first board etched, the ink and toner get washed off and the second layer is carefully lined up, put through the laminator, and then the opposite side gets covered in ink for the second acid bath.

After the process is complete and many layers of ink and toner are removed, [Bettina] is left with a PCB that’s ready to receive electronic components, if a little stained from all the ink. As to what this specific board is going to be used for, she’s kept that a bit cryptic as it’s the subject of a future video. Her builds usually revolve around designs from antique elecronics magazines, so it’s almost certainly something of that nature, and that’s also why this specific design couldn’t be just sent off to a board shop.

Continue reading “Improved Double-Sided Toner Transfer Method” →