Perfecting The Shape-Changing Fruit Bowl

March 13, 2026 by No comments

Fruit bowls have an unavoidable annoyance– not flies and rotten fruit, those would be avoidable if your diet was better. No, it’s that the bowl is never the right size. Either your fruit is sad and lonely in a too-large bowl, or it’s falling out. It’s the kind of existential nightmare that can only be properly illustrated by a late-night infomercial. [Simone Giertz] has a solution to the problem: a shape-changing fruit bowl.

See, it was one thing to make a bowl that could change shape. That was easy, [Simone] had multiple working prototypes. There are probably many ways to do it, but we like [Simone]’s use of an iris mechanism in a flat base to allow radial expansion of the walls. The problem was that [Simone] has that whole designer thing going on, and needs the bowl to be not only functional, but aesthetically pleasing. Oh, and it would be nice if expanding the bowl didn’t create escape routes for smaller fruits, but that got solved many prototypes before it got pretty.

It’s neat to see her design process. Using 3D printing and CNC machining for prototyping is very familiar to Hackaday, but lets be honest — for our own projects, it’s pretty common to stop at “functional”. Watching [Simone] struggle to balance aesthetics with design-for-manufacturing makes for an interesting 15 minutes, if nothing else. Plus she gives us our inspirational quote of the day: “As much as I feel like I’m walking in circles, I know that product development is a spiral”. Something to keep in mind next time it seems like you’re going around the drain in your own projects. Just be warned, she does have a bit of a potty mouth.

We’ve featured [Simone]’s design decisions here, if you’re interested in seeing how she goes the rest of the way from project to product. We’re pretty sure her face-slapping-alarm clock never made it into the SkyMall catalog, though.

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Nintendo’s Family BASIC Keyboard Gets USB Upgrade

March 12, 2026 by No comments

America knew it as the Nintendo Entertainment System, but in Japan, it was the Family Computer (Famicom). It was more than just a home console—it was intended to actually do a whole lot more. All you had to do was plug in the keyboard and chuck in the right Family BASIC cartridge, and you had a computer hooked up to your TV! [Lucas Leadbetter] came across an old Family BASIC keyboard recently, and set about making it more useful in our modern age with a simple USB upgrade.

[Lucas] started with research, and soon found plenty of schematics and details on the keyboard on the NESdev wiki page. Hunting further turned up a video from [Circuit Rewind], who demonstrated how to hook up the keyboard to a Raspberry Pi Pico, including how to interface with the onboard chips to scan the keys. These resources told [Lucas] enough to get going—and that it should be as simple as wiring some custom hardware up to the internal keyboard matrix connector to get it speaking to USB.

[Lucas] went a slightly different path to [Circuit Rewind], implementing the popular QMK firmware to suit the Family Basic keyboard on an Adafruit KB2040. The Adafruit part is basically an RP2040 microcontroller slapped onto a tiny PCB in a form factor that’s ideal for making custom keyboards. [Lucas] was able to reimplement the scanning logic that [Circuit Rewind] had reverse engineered previously, and had the keyboard up and running in short order with all the usability benefits of the QMK firmware. Files are on Github for those eager to recreate the work.

As far as usability goes, [Lucas] notes that the Family BASIC keyboard is more of a conversation piece than a daily driver, thanks to its rather poor feel. Duly noted. We’ve explored how software development is done in Family BASIC before, too. Video after the break.

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Replicating A Nuclear Event Detector For Fun And Probably Not Profit

March 12, 2026 by 9 Comments

Last year, we brought you a story about the BhangmeterV2, an internet-of-things nuclear war monitor. With a cold-war-era HSN-1000 nuclear event detector at its heart, it had one job: announce to everything else on the network than an EMP was inbound, hopefully with enough time to shut down electronics. We were shocked to find out that the HSN-1000 detector was still available at the time, but that time has now passed. Fortunately [Bigcrimping] has stepped up to replicate the now-unobtainable component at the heart of his build with his BHG-2000 Nuclear Event Detector — but he needs your help to finish the job. Continue reading “Replicating A Nuclear Event Detector For Fun And Probably Not Profit” →

Building A Robot Partner To Play Air Hockey With

March 12, 2026 by 1 Comment

Air hockey is one of those sports that’s both incredibly fun, but also incredibly frustrating as playing it by yourself is a rather lonely and unfulfilling experience. This is where an air hockey playing robot like the one by [Basement Builds] could come in handy. After all, after you finished building an air hockey table from scratch, how hard could it be to make a robot that merely moves the paddle around to hit the puck with?

An air hockey table is indeed not extremely complicated, being mostly just a chamber that has lots of small holes on the top through which the air is pushed. This creates the air layer on which the puck appears to float, and allows for super-fast movement. For this part countless chamfered holes were drilled to get smooth airflow, with an inline 12VDC duct fan providing up to 270 CFM (~7.6 m3/minute).

Initially the robot used a CoreXY gantry configuration, which proved to be unreliable and rather cumbersome, so instead two motors were used, each connected to its own gearbox. These manipulate the paddle position by changing the geometry of the arms. Interestingly, the gearbox uses TPU for its gears to absorb any impacts and increase endurance as pure PLA ended up falling apart.

The position of the puck is recorded by an overhead camera, from where a Python script – using the OpenCV library running on a PC – determines how to adjust the arms, which is executed by Arduino C++ code running on a board attached to the robot. All of this is available on GitHub, which as the video makes clear is basically cheating as you don’t get to enjoy doing all the trigonometry and physics-related calculating and debugging fun.

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Mapping The Sound Field Of An Acoustic Levitator

March 12, 2026 by No comments

Sound! It’s a thing you hear, moreso than something you see with your eyes. And yet, it is possible to visualize sound with various techniques. [PlasmatronX] demonstrates this well, using a special scanning technique to visually capture the sound field inside an acoustic levitation device. 

If you’re unfamiliar, acoustic levitation devices like this use ultrasound to create standing waves that can hold small, lightweight particles in mid-air. The various nodes of the standing wave are where particles will end up hovering. [PlasmatronX] was trying to calibrate such a device, but it proved difficult without being able to see what was going on with the sound field. Hence, the desire to image it!

Imaging the sound field was achieved with a Schlieren optical setup, which can capture variations in air density as changes in brightness in an image. Normally, Schlieren imaging only works in a two-dimensional slice. However, [PlasmatronX] was able to lean on computed tomography techniques to create a volumetric representation of the sound field in 3D. He refers to this as “computerized acoustical tomography.” Images were captured of the acoustic levitation rig from different angles using the Schlieren optics rig, and then the images were processed in Python to recreate a 3D image of the sound field.

We’ve seen some other entertaining applications of computed tomography techniques before, like inspecting packets of Pokemon cards. Video after the break.

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How Would A Field Sequential Home Computer Have Worked?

March 12, 2026 by 13 Comments

The early history of colour TV had several false starts, of which perhaps one of the most interesting might-have-beens was the CBS field-sequential system. This was a rival to the nascent system which would become NTSC, which instead of encoding red, green, and blue all at once for each pixel, made sequential frames carry them.

The Korean war stopped colour TV development for its duration in the early 1950s, and by the end of hostilities NTSC had matured into what we know today, so field-sequential colour became a historical footnote. But what if it had survived? [Nicole Express] takes into this alternative history, with a look at how a field-sequential 8-bit home computer might have worked.

The CBS system had a much higher line frequency in order to squeeze in those extra frames without lowering the overall frame rate, so given the clock speeds of the 8-bit era it rapidly becomes obvious that a field-sequential computer would be restricted to a lower pixel resolution than its NTSC cousin. The fantasy computer discussed leans heavily on the Apple II, and we explore in depth the clock scheme of that machine.

While it would have been possible with the faster memory chips of the day to achieve a higher resolution, the conclusion is that the processor itself wasn’t up to matching the required speed. So the field-sequential computer would end up with wide pixels. After a look at a Breakout clone and how a field-sequential Atari 2600 might have worked, there’s a conclusion that field-sequential 8-bit machines would not be as practical as their NTSC cousins. From where we’re sitting we’d expect them to have used dedicated field-sequential CRT controller chips to take away some of the heartache, but such fantasy silicon really is pushing the boundaries.

Meanwhile, while field-sequential broadcast TV never made it, we do have field-sequential TV here in 2026, in the form of DLP projectors. We’ve seen their spinning filter disks in a project or two.

1950 CBS color logo: Archive.org, CC0.

Controlling Vintage Mac OS With AI

March 12, 2026 by 6 Comments

Classic Mac OS was prized for its clean, accessible GUI when it first hit the scene in the 1980s. Back then, developers hadn’t even conceived of all the weird gewgaws that would eventually be shoehorned into modern operating systems, least of all AI agents that seem to be permeating everything these days. And yet! [SeanFDZ] found a way to cram Claude or other AI agents into the vintage Mac world.

The result of [Sean]’s work is AgentBridge, a tool for interfacing modern AI agents with vintage Mac OS (7-9). AgentBridge itself runs as an application within Mac OS. It works by reading and writing text files in a shared folder which can also be accessed by Claude or whichever AI agent is in use. AgentBridge takes commands from its “inbox”, executes them via the Mac Toolbox, and then writes outputs to its “outbox” where they can be picked up and processed by the AI agent. The specifics of how the shared folder work are up to you—you can use a network share, a shared folder in an emulation environment, or just about any other setup that lets the AI agent and AgentBridge access the same folder.

It’s hard to imagine any mainstream use cases for having a fleet of AI-controlled Macintosh SE/30s. Still, that doesn’t mean we don’t find the concept hilarious. Meanwhile, have you considered the prospect of artificial intelligence running on the Commodore 64?