2025-12-11 17:00:21
The age of cheap and powerful devices is upon us. How about a 20 EUR handheld game console intended for retro game emulation, that runs Linux under the hood? [Luiz Ferreira] kicks the tires of a R36S, a very popular and often cloned device running a quad-core RK3326 with an Ubuntu-based OS, and shows us how to write and cross-compile a simple app for it using Rust – even if you daily drive Windows.
Since a fair bit of the underlying Linux OS is exposed, you can quickly build even text applications and have them run on the console. For instance, [Luiz]’s app uses ratatui to scan then print button and joystick states to the screen. Perhaps the most important thing about this app is that it’s a detailed tutorial on cross-compiling Rust apps for a Linux target, and it runs wonders using WSL, too.
Installing your app is simple, too: SSH into it, username ark and password ark. Looking for a Linux-powered device with a bright screen, WiFi, a fair few rugged buttons, and an OS open for exploration? This one is quite reassuring in the age of usual portables like smartphones getting more and more closed-off to tinkering. And, if the store-bought hackable Linux consoles still aren’t enough, you can always step it up and build your own, reusing Joycons for your input needs while at it.
2025-12-11 14:00:00
The Dutch word for sundial, zonnewijzer, can be literally translated into “Sun Pointer” according to [illusionmanager] — and he took that literal translation literally, building a reverse sundial so he would always know the precise location of our local star, even when it is occluded by clouds or the rest of the planet.
The electronics aren’t hugely complicated: an ESP32 dev board, an RTC board, and a couple of steppers. But the craftsmanship is, as usual for [illusionmanager], impeccable. You might guess that one motor controls the altitude and the other the azimuth of the LED-filament pointer (a neat find from AliExpress), but you’d be wrong.
This is more like an equatorial mount, in that the shaft the arrow spins upon is bent at a 23.5 degree angle. Through that hollow shaft a spring-steel wire connects the arrow to one stepper, to drive it through the day. The second stepper turns the shaft to keep the axis pointed correctly as Earth orbits the sun.
Either way you can get an arrow that always points at the sun, but this is lot more elegant than an alt-az mount would have been, at the expense of a fiddlier build. Given the existence of the orrery clock we featured from him previously, it’s safe to say that [illusionmanager] is not afraid of a fiddly build. Doing it this way also lets you read the ticks on the base just as you would a real sundial, which takes this from discussion piece to (semi) usable clock.
2025-12-11 11:00:26
For as long as there have been supercomputers, people like us have seen the announcements and said, “Boy! I’d love to get some time on that computer.” But now that most of us have computers and phones that greatly outpace a Cray 2, what are we doing with them? Of course, a supercomputer today is still bigger than your PC by a long shot, and if you actually have a use case for one, [Stephen Wolfram] shows you how you can easily scale up your processing by borrowing resources from the Wolfram Compute Services. It isn’t free, but you pay with Wolfram service credits, which are not terribly expensive, especially compared to buying a supercomputer.
[Stephen] says he has about 200 cores of local processing at his house, and he still sometimes has programs that run overnight. If your program already uses a Wolfram language and uses parallelism — something easy to do with that toolbox — you can simply submit a remote batch job.
What constitutes a supercomputer? You get to pick. You can just offload your local machine using a single-core 8GB virtual machine — still a supercomputer by 1980s standards. Or you get machines with up to 1.5TB of RAM and 192 cores. Not enough for your mad science? No worries, you can map a computation across more than one machine, too.
As an example, [Stephen] shows a simple program that tiles pentagons:
When the number of pentagons gets large, a single line of code sends it off to the cloud:
RemoteBatchSubmit[PentagonTiling[500]]
The basic machine class did the work in six minutes and 30 seconds for a cost of 5.39 credits. He also shows a meatier problem running on a 192-core 384GB machine. That job took less than two hours and cost a little under 11,000 credits (credit cost from just over $4/1000 to $6/1000, depending on how many you buy, so this job cost about $55 to run). If two hours is too much, you can map the same job across many small machines, get the answer in a few minutes, and spend fewer credits in the process.
Supercomputers today are both very different from old supercomputers and yet still somewhat the same. If you really want that time on the Cray you always wanted, you might think about simulation.
2025-12-11 08:00:52
There’s a type of dust-collector that’s been popular since the 1990s, where a cube of acrylic or glass is laser-etched in a three-dimensional pattern. Some people call them bubblegrams. While it could be argued that bubblegrams are a sort of 3D display, they’re more like a photograph than a TV. [Ancient] had the brainwave that since these objects work by scattering light, he could use them as a proper 3D video display by controlling the light scattered from an appropriately-designed bubblegram.
Appropriately designed, in this case, means a point cloud, which is not exactly exciting to look at on its own. It’s when [Ancient] adds the colour laser scanning projector that things get exciting. Well, after some very careful alignment. We imagine if this was to go on to become more than a demonstrator some sort of machine-vision auto-aligning would be desirable, but [Ancient] is able to conquer three-dimensional keystoning manually for this demonstration. Considering he is, in effect, projection-mapping onto the tiny bubbles in the crystal, that’s impressive work. Check out the video embedded below.
With only around 38,000 points, the resolution isn’t exactly high-def, but it is enough for a very impressive proof-of-concept. It’s also not nearly as creepy as the Selectric-inspired mouth-ball that was the last [Ancient] project we featured. It’s also a lot less likely to take your fingers off than the POV-based volumetric display [Ancient] was playing DOOM on a while back.
For the record, this one runs the same DOOM port, too– it’s using the same basic code as [Ancient]’s other displays, which you can find on GitHub under an MIT license.
Thanks to [Hari Wiguna] for the tip.
2025-12-11 05:00:53
Ever think about all the moving parts involving a big KiCad project going into production? You need to provide manufacturer documentation, assembly instructions and renders for them to reference, every output file they could want, and all of it has to always stay up to date. [Vincent Nguyen] has a software pipeline to create all the files and documentation you could ever want upon release – with an extensive installation and usage guide, helping you turn your KiCad projects truly production-grade.
This KiBot-based project template has no shortage of features. It generates assembly documents with custom processing for a number of production scenarios like DNPs, stackup and drill tables, fab notes, it adds features like table of contents and 3D renders into KiCad-produced documents as compared to KiCad’s spartan defaults, and it autogenerates all the outputs you could want – from Gerbers, .step and BOM files, to ERC/DRC reports and visual diffs.
This pipeline is Github-tailored, but it can also be run locally, and it works wonderfully for those moments when you need to release a PCB into the wild, while making sure that the least amount of things possible can go wrong during production. With all the features, it might take a bit to get used to. Don’t need fully-featured, just some GitHub page images? Use this simple plugin to auto-add render images in your KiCad repositories, then.
We thank [Jaac] for sharing this with us!
2025-12-11 03:30:26
This week Jonathan chats with K. S. Bhaskar about YottaDB. This very high performance database has some unique tricks! How does YottaDB run across multiple processes without a daemon? Why is it licensed AGPL, and how does that work with commercial deployments? Watch to find out!
Did you know you can watch the live recording of the show right on our YouTube Channel? Have someone you’d like us to interview? Let us know, or have the guest contact us! Take a look at the schedule here.
Direct Download in DRM-free MP3.
If you’d rather read along, here’s the transcript for this week’s episode.
Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
