The five picos on two breadboards and the results of image convolution.

PentaPico: A Pi Pico Cluster For Image Convolution

May 20, 2025 by John Elliot V 22 Comments

Here’s something fun. Our hacker [Willow Cunningham] has sent us a copy of their homework. This is their final project for the “ECE 574: Cluster Computing” course at the University of Maine, Orono.

It was enjoyable going through the process of having a good look at everything in this project. The project is a “cluster” of 5x Raspberry Pi Pico microcontrollers — with one head node as the leader and four compute nodes that work on tasks. The software for both types of node is written in C. The head node is connected to a workstation via USB 1.1 allowing the system to be controlled with a Python script.

The cluster is configured to process an embarrassingly parallel image convolution. The input image is copied into the head node via USB which then divvies it up and distributes it to n compute nodes via I²C, one node at a time. Results are given for n = {1,2,4} compute nodes.

It turns out that the work of distributing the data dwarfs the compute by three orders of magnitude. The result is that the whole system gets slower the more nodes we add. But we’re not going to hold that against anyone. This was a fascinating investigation and we were impressed by [Willow]’s technical chops. This was a complicated project with diverse hardware and software challenges and they’ve done a great job making it all work and in the best scientific tradition.

It was fun reading their journal in which they chronicled their progress and frustrations during the project. Their final report in IEEE format was created using LaTeX and Overleaf, at only six pages it is an easy and interesting read.

For anyone interested in cluster tech be sure to check out the 256-core RISC-V megacluster and a RISC-V supercluster for very low cost.

An Open-Source Wii U Gamepad

May 19, 2025 by Bryan Cockfield 8 Comments

Although Nintendo is mostly famous for making great games, they also have an infamous reputation for being highly litigious not only for reasonable qualms like outright piracy of their games, but additionally for more gray areas like homebrew development on their platforms or posting gameplay videos online. With that sort of reputation it’s not surprising that they don’t release open-source drivers for their platforms, especially those like the Wii U with unique controllers that are difficult to emulate. This Wii U gamepad emulator seeks to bridge that gap.

The major issue with the Wii U compared to other Nintendo platforms like the SNES or GameCube is that the controller looks like a standalone console and behaves similarly as well, with its own built-in screen. Buying replacement controllers for this unusual device isn’t straightforward either; outside of Japan Nintendo did not offer an easy path for consumers to buy controllers. This software suite, called Vanilla, aims to allow other non-Nintendo hardware to bridge this gap, bringing in support for things like the Steam Deck, the Nintendo Switch, various Linux devices, or Android smartphones which all have the touch screens required for Wii U controllers. The only other hardware requirement is that the device must support 802.11n 5 GHz Wi-Fi.

Although the Wii U was somewhat of a flop commercially, it seems to be experiencing a bit of a resurgence among collectors, retro gaming enthusiasts, and homebrew gaming developers as well. Many games were incredibly well made and are still experiencing continued life on the Switch, and plenty of gamers are looking for the original experience on the Wii U instead. If you’ve somehow found yourself in the opposite position of owning of a Wii U controller but not the console, though, you can still get all the Wii U functionality back with this console modification.

Thanks to [Kat] for the tip!

3D Printing Uranium-Carbide Structures For Nuclear Applications

May 19, 2025 by Maya Posch 11 Comments

Fabrication of uranium-based components via DLP. (Zanini et al., Advanced Functional Materials, 2024)

Within the nuclear sciences, including fuel production and nuclear medicine (radiopharmaceuticals), often specific isotopes have to be produced as efficiently as possible, or allow for the formation of (gaseous) fission products and improved cooling without compromising the fuel. Here having the target material possess an optimized 3D shape to increase surface area and safely expel gases during nuclear fission can be hugely beneficial, but producing these shapes in an efficient way is complicated. Here using photopolymer-based stereolithography (SLA) as recently demonstrated by [Alice Zanini] et al. with a research article in Advanced Functional Materials provides an interesting new method to accomplish these goals.

In what is essentially the same as what a hobbyist resin-based SLA printer does, the photopolymer here is composed of uranyl ions as the photoactive component along with carbon precursors, creating solid uranium dicarbide (UC₂) structures upon exposure to UV light with subsequent sintering. Uranium-carbide is one of the alternatives being considered for today’s uranium ceramic fuels in fission reactors, with this method possibly providing a reasonable manufacturing method.

Uranium carbide is also used as one of the target materials in ISOL (isotope separation on-line) facilities like CERN’s ISOLDE, where having precise control over the molecular structure of the target could optimize isotope production. Ideally equivalent photocatalysts to uranyl can be found to create other optimized targets made of other isotopes as well, but as a demonstration of how SLA (DLP or otherwise) stands to transform the nuclear sciences and industries.

Overengineered Freezer Monitor Fills Market Void

May 19, 2025 by Bryan Cockfield 27 Comments

A lot of projects we see around here are built not just because they can be built, but because there’s no other option available. Necessity is the mother of invention, as they say. And for [Jeff] who has many thousands of dollars of food stowed in a chest freezer, his need for something to keep track of his freezer’s status was greater than any commercial offering available. Not only are freezers hard on batteries, they’re hard on WiFi signals as well, so [Jeff] built his own temperature monitor to solve both of these issues.

The obvious solution here is to have a temperature probe that can be fished through the freezer in some way, allowing the microcontroller, battery, and wireless module to operate outside of the harsh environment. [Jeff] is using K-type thermocouples here, wired through the back of the freezer. This one also is built into a block of material which allows him to get more diffuse temperature readings than a standard probe would provide. He’s also solving some other problems with commercially available probes here as well, as many of them require an Internet connection or store data in a cloud. To make sure everything stays local, he’s tying this in to a Home Assistant setup which also allows him to easily make temperature calibrations as well as notify him if anything happens to the freezer.

Although the build is very robust (or, as [Jeff] himself argues, overengineered) he does note that since he built it there have been some additional products offered for sale that fit this niche application. But even so, we always appreciate the customized DIY solution that avoids things like proprietary software, subscriptions, or cloud services. We also appreciate freezers themselves; one of our favorites was this restoration of a freezer with a $700,000 price tag.

Easy Panels With InkJet, Adhesives, And Elbow Grease

May 19, 2025 by Tyler August 25 Comments

Nothing caps off a great project like a good, professional-looking front panel. Looking good isn’t easy, but luckily [Accidental Science] has a tutorial for a quick-and-easy front panel technique in the video below.

It starts with regular paper, and an inkjet or laser printer to print your design. The paper then gets coated on both sides: matte varnish on the front, and white spray paint on the back. Then it’s just a matter of cutting the decal from the paper, and it gluing to your panel. ([Accidental Science] suggests two-part epoxy, but cautions you make sure it does not react to the paint.)

He uses aluminum in this example, but there’s no reason you could not choose a different substrate. Once the paper is adhered to the panel, another coat of varnish is applied to protect it. Alternatively, clear epoxy can be used as glue and varnish. The finish produced is very professional, and holds up to drilling and filing the holes in the panel.

We’d probably want to protect the edges by mounting this panel in a frame, but otherwise would be proud to put such a panel on a project that required it. We covered a similar technique before, but it required a laminator.If you’re looking for alternatives, Hackaday community had a lot of ideas on how to make a panel, but if you have a method you’ve documented, feel free to put in the tip line. Continue reading “Easy Panels With InkJet, Adhesives, And Elbow Grease” →

A UV Meter For The Flipper Zero

May 19, 2025 by Matt Varian 6 Comments

We all know UV radiation for its contributions to getting sunburned after a long day outside, but were you aware there are several types different types of UV rays at play? [Michael] has come up with a Flipper Zero add on board and app to measure these three types of radiation, and explained some of the nuances he learned about measuring UV along the way.

At the heart of this project is an AS7331 sensor, it can measure the UV-A, UV-B, and UV-C radiation values that the Flipper Zero reads via I2C. While first using this chip he realized to read these values is more complex than just querying the right register, and by the end of this project he’d written his own AS7331 library to help retrieve these values. There was also a some experimenting with different GUI designs for the app, the Flipper Zero screen is only 128x64px and he had a lot of data to display. One feature we really enjoyed was the addition of the wiring guide to the app, if you install this Flipper Zero app and have just the AS7331 sensor on hand you’ll know how to hook it up. However if you want he also has provided the design files for a PCB that just plugs into the top of the Flipper Zero.

Head over to his site to check out all the details of this Flipper Zero project, and to learn more about the different types of UV radiation. Also be sure to let us know about any of your Flipper Zero projects.

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Wafer-Thin Keyboard

May 19, 2025 by Kristina Panos 8 Comments

The mikecinq, an incredibly slim keyboard. — Image by [dynam1keNL] via reddit

But sir! I can’t believe I missed [dynam1keNL]’s initial flat offering from about a year ago, the mikefive, which came about when he and some friends ordered switches directly from Kailh and Kailh were like, do you want to try these even lower-profile PG1316 laptop switches? It’s called the mikefive because it’s 5 mm thick.

That’s okay, though, because now you’re caught up and I can talk about his latest keyboard, the mikecinq. The inspiration for this one includes the aesthetics of Le Chiffre and the slimness of Le Oeuf. As you’ll see in the gallery, the top is ever-so-slightly slanted downward from the top.

You can see it really well in the second picture — the top row is flush with the case, and the keys gradually get taller toward the thumb clusters. All [dynam1keNL] really had to do was 3D model the new case and screw in the PCB from his daily driver mikefive.

[dynam1keNL] ultimately found it nice and comfy, especially for the thumbs, but decided to take it one step further and designed a new switch footprint. Why? The PG1316s are surface-mount with contacts below the switch, so you really need a hotplate or oven to mount them.

So in order to deal with this, he made a dedicated mikecinq PCB with big cutouts with castellated holes beneath each switch. Now, the switch contacts are accessible from underneath and can be soldered with an iron.

You may have noticed that the mikefive production files are not available on GitHub — that’s because it was recently licensed and will be available soon. But if you want production files for the mikecinq, let him know in the comments.

Continue reading “Keebin’ With Kristina: The One With The Wafer-Thin Keyboard” →