Learn What A Gaussian Splat Is, Then Make One

October 31, 2025 by Donald Papp 16 Comments

Gaussian Splats is a term you have likely come across, probably in relation to 3D scenery. But what are they, exactly? This blog post explains precisely that in no time at all, complete with great interactive examples and highlights of their strengths and relative weaknesses.

Gaussian splats excel at making colorful, organic subject matter look great.

Gaussian splats are a lot like point clouds, except the points are each differently-shaped “splats” of color, arranged in such a way that the resulting 3D scene looks fantastic — photorealistic, even — from any angle.

All of the real work is in the initial setup of the splats into the scene. Once that work is done, viewing is the easy part. Not only are the resulting file sizes of the scenes small, but rendering is computationally simple.

There are a few pros and cons to gaussian splats compared to 3D meshes, but in general they look stunning for any kind of colorful, organic scene. So how does one go about making or using them?

That’s where the second half of the post comes in handy. It turns out that making your own gaussian splats is simply a matter of combining high-quality photos with the right software. In that sense, it has a lot in common with photogrammetry.

Even early on, gaussian splats were notable for their high realism. And since this space has more than its share of lateral-thinkers, the novel concept of splats being neither pixels nor voxels has led some enterprising folks to try to apply the concept to 3D printing.

This Board Helps You Prototype Circuits With Tubes

September 14, 2025 by Seth Mabbott 12 Comments

There you are at the surplus store, staring into the bin of faded orange, yellow, red, and black, boxes–a treasure trove of vintage vacuum tubes—dreaming about building a tube amp for your guitar or a phonograph preamp for your DIY hi-fi sound system. But, if you are not already in possession of a vintage, purpose-built tube testing device, how would you test them to know whether they are working properly? How would you test out your designs before committing to them? Or maybe your goal is simply to play around and learn more about how tubes work.

One approach is to build yourself a breadboard for tubes, like [MarceloG19] has done. Working mostly with what was laying around, [MarceloG19] built a shallow metal box to serve as a platform for a variety of tube sockets and screw terminals. Connecting the terminals to the socket leads beneath the outer surface of the box made for a tidy and firm base on which to connect other components. The built-in on/off switch, fuse and power socket are a nice touch.

[MarceloG19’s] inaugural design is a simple Class A amplifier, tested with a sine wave and recorded music. Then it’s on to some manual curve tracing, to test a tube that turns out to be fairly worn-out but serviceable for certain use cases.

If you’re dipping your toes into tube-based electronics, you’re going to want a piece of equipment like this prototyping board and [MarceloG19’s] documentation and discussion are a good read to help get you started.

Once you have your board ready, it’s time to move on to building a stereo amplifier , a tube-based headphone preamp, or take things in a different direction with this CRT-driven audio amplifier.

GPS And Its Little Modules

September 8, 2025 by Arya Voronova 17 Comments

Ever want to find your device on the map? Think we all do sometimes. The technology you’ll generally use for that is called Global Positioning System (GPS) – listening to a flock of satellites flying in the orbit, and comparing their chirps to triangulate your position.

The GPS system, built by the United States, was the first to achieve this kind of feat. Since then, new flocks have appeared in the orbit, like the Galileo system from the European Union, GLONASS from Russia, and BeiDou from China. People refer to the concept of global positioning systems and any generic implementation as Global Navigation Satellite System (GNSS), but I’ll call it GPS for the purposes of this article, and most if not all advice here will apply no matter which one you end up relying on. After all, modern GPS modules overwhelmingly support most if not all of these systems!

We’ve had our writers like [Lewin Day] talk in-depth about GPS on our pages before, and we’ve featured a fair few projects showing and shining light on the technology. I’d like to put my own spin on it, and give you a very hands-on introduction to the main way your projects interface with GPS.

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Debugging The Instant Macropad

August 25, 2025 by Al Williams No comments

Last time, I showed you how to throw together a few modules and make a working macropad that could act like a keyboard or a mouse. My prototype was very simple, so there wasn’t much to debug. But what happens if you want to do something more complex? In this installment, I’ll show you how to add the obligatory blinking LED and, just to make it interesting, a custom macro key.

There is a way to print data from the keyboard, through the USB port, and into a program that knows how to listen for it. There are a few choices, but the qmk software can do it if you run it with the console argument.

The Plan

In theory, it is fairly easy to just add the console feature to the keyboard.json file:

{
...
    "features": {
        "mousekey": true,
        "extrakey": true,
        "nkro": false,
        "bootmagic": false,
        "console": true
    },
...

That allows the console to attach, but now you have to print.

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Instant Macropad: Just Add QMK

August 20, 2025 by Al Williams 2 Comments

I recently picked up one of those cheap macropads (and wrote about it, of course). It is surprisingly handy and quite inexpensive. But I felt bad about buying it. Something like that should be easy to build yourself. People build keyboards all the time now, and with a small number of keys, you don’t even have to scan a matrix. Just use an I/O pin per switch.

The macropad had some wacky software on it that, luckily, people have replaced with open-source alternatives. But if I were going to roll my own, it would be smart to use something like QMK, just like a big keyboard. But that made me wonder, how much trouble it would be to set up QMK for a simple project. Spoiler: It was pretty easy.

The Hardware

Simple badge or prototype macropad? Why not both?

Since I just wanted to experiment, I was tempted to jam some switches in a breadboard along with a Raspberry Pi Pico. But then I remembered the “simple badge” project I had up on a nearby shelf. It is simplicity itself: an RP2040-Plus (you could just use a regular Pi Pico) and a small add-on board with a switch “joystick,” four buttons, and a small display. You don’t really need the Plus for this project since, unlike the badge, it doesn’t need a battery. The USB cable will power the device and carry keyboard (or even mouse) commands back to the computer.

Practical? No. But it would be easy enough to wire up any kind of switches you like. I didn’t use the display, so there would be no reason to wire one up if you were trying to make a useful copy of this project.

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Zine Printing Tips From A Solopreneur

July 25, 2025 by Donald Papp 28 Comments

Zines (self-produced, small-circulation publications) are extremely DIY, and therefore punk- and hacker-adjacent by nature. While they can be made with nothing more than a home printer or photocopier, some might benefit from professional production while losing none of their core appeal. However, the professional print world has a few gotchas, and in true hacker spirit [Mabel Wynne] shares things she learned the hard way when printing her solo art zine.

As with assembling hardware kits, assembling a zine can take up a lot of physical table space.

[Mabel] says the most useful detail to nail down before even speaking to printers is the zine’s binding, because binding type can impact layout and design of an entire document. Her advice? Nail it down early, whether it’s a simple saddlestitch (staples through a v-shaped fold of sheets), spiral binding (which allows a document to lay flat), or something else.

Aside from paper and print method (which may be more or less important depending on the zine’s content) the other thing that’s important to consider is the finishing. Finishing consists of things like cutting, folding, and binding of the raw printed sheets. A printer will help arrange these, but it’s possible to do some or even all of these steps for oneself, which is not only more hands-on but reduces costs.

Do test runs, and prototype the end result in order to force unknown problems to the surface before they become design issues. Really, the fundamentals have a lot in common with designing and building kits or hardware. Check out [Mabel]’s article for the full details; she even talks a little about managing money and getting a zine onto shelves.

Zine making is the DIYer’s way to give ideas physical form and put them into peoples’ hands more or less directly, and there’s something wonderfully and inherently subversive about that concept. 2600 has its roots in print, but oddball disk magazines prove one doesn’t need paper to make a zine.

Mini Car Racing Game Really Shows Off Multicolor Printing

July 16, 2025 by Donald Papp 13 Comments

Quality 3D printing is a common hobbyist tool nowadays, and [wontonnn]’s mini arcade car racing game really shows off how 3D printing can bring parts from functional to fantastic. There are quite a few details we like in [wontonn]’s design, so let’s take a closer look.

The mini mechanical game is one of those treadmill-based car racing games in which the player navigates a little car between an onslaught of belt-borne obstacles. A little DC motor spins things up in a modular side assembly, and a hand-cranked option is available. The player’s car attaches via a magnet to a steering arm; if the player’s car gets knocked off the magnet, game over.

Treadmill belt segments print as large pre-assembled pieces, with ends that snap together without connectors. Belts like this are sometimes tricky, so this is worth keeping in mind should one ever need a similar part. Since there are no external fasteners or hardware to depend on, one could resize it easily to suit their own project purposes.

The finishing touches on the whole assembly look great. It used to be that the sort of colors and lettering seen here would come from a sticker or label, but [wontonn] gets clean lines and colors by raising (or sinking) different parts of the design. The checkerboard pattern, for example, has the light squares raised for printing in a different color.

Electromechanical arcade games have an appeal all their own, being a fusion of both mechanical and electric design that comes together in a special way. Want to make your own? Get inspired by the classic Lunar Lander reimagined, or check out this LEGO treadmill racer that takes an entirely different approach to the concept.

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