A Flip Disc Display That Does It Slow And Steady

August 31, 2026 by 1 Comment

Flip disc displays can be quite a task to drive, what with having some sort of actuator mechanism for each and every dot in the display. [Zimm] has built an altogether different kind of flip disc display, though, which gets around this with a complexity all its own.

The idea behind the build is simple. There is still an array of discs, in this case, 37 x 18 square discs that are black on one side and blue on the other. However, they’re not actuated by magnets or any kind of per-disc flipper. Instead, a CNC machine is charged with flipping them one at a time. There’s a tool head that scans through the array, and uses a color sensor and LIDAR to identify which pixels to flip and how far to push them. It’s not fast, by any means, but it’s a perfectly cromulent way to build a flip disc display, as it turns out.

If you so desire, you can draw or upload images to be displayed on PAR yourself, right from your browser. The project reminds us quite a lot of various plotters we’ve covered over the years, perhaps more than a traditional flip disc display, even.

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Making A Robot To Serve Some Mean Badminton Shuttlecocks

August 30, 2026 by No comments

Sometimes regarded as a less violent form of tennis, badminton is still a pretty challenging sport. One which suffers like so many sports from requiring at least two players since magically flying balls and shuttlecocks haven’t been invented yet. After years of tinkering on a shuttlecock serving robot, [Travis Mitchell] hit upon the idea to convert a small industrial robotic arm for the purpose.

The target of this conversion is a positively cute-sized Denso VS050 robotic arm, with Denso helpfully providing a 3D model of the arm as a solid jumping-off point in a CAD project. Here the task of the robotic arm is two-fold: one is to grab a fresh shuttlecock from a hopper with a pneumatic grabber, the other is to feed it into the spinning wheels that grip and launch it. Fortunately [Travis] has a pretty tricked-out workshop available, including the ability to 3D print metal parts, making building the prototype a snap.

After initially thinking of using a Raspberry Pi Pico, he ended up using an ATmega AVR due to the input-output requirements when communicating with the arm. Using a height-adjustable desk as the base, the whole assembly was put together for some testing on the badminton court.

With most of the testing having been done in the shop already, the remaining issue was to determine the best disc material, as the two high-speed discs that grip the shuttlecock must be well-balanced and not stretch too much. Ultimately a 3D printed plastic disc with a silicone strip as gripping surface was found to work pretty well, allowing for the robot to finally start serving its function.

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Get Your Monitor Transmitting VHF With A Browser Tool

August 30, 2026 by 14 Comments

If you’re intending to transmit on the VHF band, you’re probably going to reach for a handheld or some kind of rackmount rig in your ham shack. But you needn’t bother with all that complexity, when you can use the computer on your desk to spit out such signals using a simple browser tool from [Efe].

The concept is straightforward—[Efe]’s tool manipulates pixel clocks in order to create spurious transmissions from your computer’s graphics hardware. The math pencils out pretty easily—multiply the horizontal resolution by the vertical resolution by the refresh rate, while paying attention to the precise timing of the video standard your monitor is using, and you’ve got your transmission frequency. For example, for a screen displaying 1080p at 60 Hz, with the CEA-861 timing standard, your horizontal and vertical resolutions are 2200 and 1125 respectively when paying attention to the requisite blanking intervals. Multiply those by 60 hz, and you’ll find you’re creating a signal at 148.500 MHz. Leverage this by displaying the right pattern of black and white pixels to maximise changes in voltage state on the HDMI or DisplayPort lines, and you might create a strong enough signal that you can actually pick something up. [Efe] created a tool to display these patterns to send simple Morse code messages over VHF just by flickering your screen just right.

You can test the transmitter tool for yourself here, right in your browser. You’ll want to hold your radio’s antenna nice and close to the monitor to see if you can pick up much of a signal. After all, the monitor, connectors, and cable are all built to optimize for clear signal transmission to the display, while preventing signal from leaking out to interfere with surrounding equipment.

Of course, a fair warning—you’re not supposed to intentionally transmit on bands you’re not licensed for, even if it’s incredibly weak and unlikely for anyone else to notice in a scenario like this. Still, it’s an interesting project that shows you just how electromagnetic interference can leak out of just about anything under the right conditions.

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Hackaday Links: August 30, 2026

August 30, 2026 by 7 Comments

The big news today is, of course, the successful launch and deployment of NASA’s Nancy Grace Roman Space Telescope earlier this morning. The space agency’s latest observatory lifted off at 7:26 AM Eastern from Launch Complex 39A at Kennedy Space Center aboard a SpaceX Falcon Heavy, and by 8:00 AM it was separated from the rocket’s upper stage and flying on its own.

While the sound and fury of launch is exciting, it’s just the beginning of the journey for Roman. It will take several months for the spacecraft to complete its roughly 1.5 million-kilometer trek out to Earth’s second Lagrange point (L2), where it will set up shop near — in cosmic terms, anyway — the James Webb Space Telescope (JWST). Along the way, it will switch on and test various systems and components, with its primary 300 megapixel infrared camera scheduled to power up in three weeks or so.

There’s a lot to cover about the Roman Space Telescope. Built from spy satellite spare parts donated by the National Reconnaissance Office and featuring a field of view 100 times greater than that of Hubble, its launch is widely considered to be one of the most important scientific milestones of the decade. We’ll be bringing you more about the past, present, and future of this flagship mission as it progresses.

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Dissecting A Lethal Universal Travel Adapter

August 30, 2026 by 29 Comments

The world’s refusal to standardize on a single type of mains power outlet has led to a vibrant market of so-called travel adapters, all of which try to outdo each other in convenience and universality. This comes at the cost of complexity, something which ultimately reflects in the price. The cheapo $9.26 universal travel adapter that [Brainiac 75] got off an online retailer’s site is thereby a good example of how safety suffers if the overarching goal is to ‘make it cheap’.

The first exciting discovery is that when you plug any of its three sets of connectors into an outlet, the others become live at the same voltage. This would suggest that they’re just wired together, a fact soon confirmed with a quick resistance check between the respective prongs. Though to the adapter’s credit, the prongs are not live when fully retracted into the enclosure. Yet as demonstrated in the video, the retracting of prongs is not enforced, so mistakes here are possible.

The adapter also has two USB ports that claim to provide 5 V at 2.1 A, with as it turns out no hard cut-off. This is probably the best part of the adapter despite not featuring any advanced charging features. After opening the adapter, you can see that the sliding mains prongs connect to a central bus bar when either unfolded or extended, which is definitely straightforward, but doesn’t enforce that only one type of prongs can be used at any given time.

To make it safer, [Brainiac75] removed the less useful US and UK plugs, taping over the empty holes. It’s now just a USB charger with a universal mains port to plug random non-EU plugs into, which is probably relatively safe and a better idea than really using it as a travel adapter.

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LLM Moats Quickly Evaporating

August 30, 2026 by 42 Comments

In the business world, a moat is a quality of a business that makes it difficult for competitors to take that company’s profits. With how hard it is to train models for large language models (LLMs) and generative AI, it might seem like Anthropic, Open AI, and other LLM companies would have huge moats given the amount of compute it takes to build models. But open source models are quickly draining that moat, and now the only thing standing in the way of a customer using one of these models on their own hardware instead one from the larger companies is physical computing resources. [TerminalBytes] demonstrates a few of these models on personally owned computers to show the current state of the art.

[TerminalBytes] started off running the 27B version of the Qwen3.8 on a Mac Studio with 256 GB of unified RAM, which is plenty for this task. But it’s also enough to benchmark a few different models. Qwen3.6 is compared to 3.8, and then the different quants of each model are also compared. Quants are compressed versions of models that need fewer bits to store weights, meaning that the same models can run in less memory with smaller losses in fidelity. Many of these quants run on machines with 32 GB of RAM or less, encompassing many average gaming PCs. There’s even a 1-bit quant that [TerminalBytes] tested which can easily run on a machine with 16 GB, although with mixed results.

Keep in mind that this is just the current state of affairs with open LLMs. Future versions of these models are likely to optimize the number of tokens produced per unit time, or otherwise increase quality of responses while requiring less computer resources. We don’t really think that the ease of running local models will be the sole reason that the AI bubble pops, though. The fact that not every computer user is running Linux is proof enough of that.

Low(er)-Cost Humanoid Robot Leverages DIY Actuators

August 30, 2026 by 11 Comments

Humanoid robots, even scaled-down ones, tend to be expensive. The Berkeley Humanoid Lite offers a more accessible and economical option by centering the design around 3D printed actuators that make up the bulk of the robot’s frame.

The actuators are made by combining motors with printed cycloidal gearboxes and an embedded magnetic encoder. They’re modular, so even if one has no desire to recreate the whole robot it might be worth checking out the actuator design details to see if they might be useful in some other way.

The Berkeley Humanoid Lite isn’t a finished product so much as an open-source, easily customized reference design. The GitHub repository contains everything one might need, and you can watch some basic demonstrations, including VR-driven teleoperation, in the video embedded below.

At a total hardware cost of under $5,000 USD it’s still expensive, but much more economical than other humanoid robots, open-source or not. As mentioned, even if one doesn’t plan to build one, the modular actuator design is worth keeping in mind for other purposes.
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