Robot Chess But Each Piece Is A Small Robot

June 13, 2026 by Maya Posch 6 Comments

A topless chess piece. (Credit: 3DprintedLife, YouTube)

We have seen a number of self-playing chess boards over the years, but the general theme has been standard chess pieces moved by either an internal electromagnet or an external robotic arm. This is, of course, a reasonable choice, as it reduces complexity, and sometimes you can even use standard chess pieces on a regular board. But what if each piece could move by itself? That seems cooler, so that’s what [3DprintedLife] did with 3D-printed chess pieces that are also tiny robots.

Although technically not the first, as you can buy the commercial Chessnut Move offering, this being an open hardware and source project makes it a lot more interesting, also because the general design is generic enough to be usable for applications other than just playing chess.

The MiniBots, as the individual pieces are called, are built around a custom PCB with an ESP32-C3 module, two PMO8-2 miniature stepper motors with requisite drivers, a magnetometer, and are powered by a 170 mAh LiPo battery. Communication with the central hub is done using ESP-NOW, with each MiniBot using its own dedicated channel.

This hub’s mainboard also runs on an ESP32-C3 for the wireless interface, while the processing is handled via a serial link with a Raspberry Pi SBC that runs the main Python-based software. Localizing the individual pieces on the board is done by scanning electromagnets embedded in the board and using the readings from the individual magnetometers to triangulate the positions.

Although at the end of the video a basic prototype sort of works, the ESP32-C3, being a single-core MCU, tripped up the firmware, necessitating some changes that should be in the next update, along with power saving and easier recharging being issues to address.

If you want to see a more conventional chess robot, we’ve seen plenty.

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Converting A Scanning Electron Microscope Into A TEM Is Surprisingly Easy

June 13, 2026 by Maya Posch 6 Comments

Although both a SEM and a TEM are electron microscopes, their working principles and images are very different. Whereas an SEM uses secondary electrons ejected after bombarding a sample’s surface with primary electrons, a TEM works more like an X-ray machine, with a sensor placed behind the sample to record primary electrons after they pass through said sample. It is, however, possible to turn a SEM into a TEM with some creativity, as [ProjectsInFlight] recently did with his SEM.

We previously covered how the SEM in the video was saved from being scrapped and subsequently revived, and now it is getting a pretty nice upgrade. That said, this SEM to TEM change isn’t anything new, with so-called STEM imaging having been possible for ages using a rather simple reflecting adapter. The problem here is that such adapters cost enough to make you dread filing a budget request, yet they are simple enough that you might be able to DIY one.

The main concern with the DIY adapter was clearance between the sample holder and the fragile components inside the chamber. This turned out to be a hair under 14 mm (0.55″), giving not a lot of space to work with, but that was relative to the standard bulky sample holder. With a thinner sample plate machined out of aluminum, significantly more space became available, including for the primary electron mirror and shield for the secondary electrons.

Some more lathe, milling, and tapping work later, the entire sample holder came together. During testing a hack was implemented to enable adjusting the mirror angle while in the evacuated vacuum chamber so that the adapter could be dialed-in. Subsequently, a first sample was imagined in the form of gold nanoparticles, which revealed a leaky secondary electron shield due to bypassing.

Further testing revealed that the shield needed to extend much higher to meaningfully block secondary electrons, after which the TEM image massively improved. Subsequently, a previously expired mosquito graciously donated its wings to science, with TEM imaging clearly revealing the delicate structures within these wonders of evolutionary design.

The next challenge will be to TEM image biological cells, which require substantial preparation.

This isn’t the first STEM converter we’ve seen. The SEM has a long checkered history that we’ve talked about before, too.

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Deeply Optimized MSX Emulation On ESP32-S3 With VGA Output

June 12, 2026 by Maya Posch 9 Comments

ESP32-S3 board with VGA and audio output during development. (Credit: Ivan Svarkovsky)

The ESP32-S3 is by many metrics quite the powerful little computer, which has led to it being used even for things like emulating retro consoles and similar. Here [Ivan Svarkovsky]’s S3-MSX-PC project pushes the envelope by taking the multi-system Retro-Go project’s MSX component and optimizing it for the ESP32-S3’s Xtensa Lx7 CPU cores.

The project involves an ESP32-S3 as the core, requiring at least 8 MB of PSRAM (N16R8 configuration) to match the tested configuration. Any software is loaded into PSRAM before it’s executed, with the MSX1, MSX2 and MSX2+ supported.

For audio you have to wire up your own PDM filters to connect to the two GPIO pins that are used for audio output, while VGA output is handled by a basic 2-bit R-2R RGB222 DAC. For input devices you can use any USB keyboard, while software is added via the web interface or directly onto an SD card.

The Technical Deep Dive section goes into more detail as to what exactly got changed – with the blessing of the fMSX author – in the original fMSX core, such as targeting the Lx7 core’s cache dimensions and optimizing hot paths to avoid bottlenecks. Memory accesses were aligned for Xtensa and moving certain data from Flash to RAM was another change, along with the prevention of pipeline flushing due to certain branching decisions.

Considering that MSX specifications are based on a Z80 core, it’s not so crazy that one of these ESP32-S3 MCUs can effectively emulate them. The Retro-Go project itself claims to cover a whole swath of Nintendo and Sega consoles, as well as others, making it almost too easy to do some retrogaming without even having to drag out a Raspberry Pi SBC or so.

Building A 1:150 Scale Toyota ProBox Micro Remote Control Car

June 12, 2026 by Maya Posch 9 Comments

Although in our imagination those scale models of cars certainly can drive and steer just like their full-scale counterparts, there’s something incredibly satisfying about watching them truly come to life. Here [diorama111] is an absolute master at the craft, with the most recent conversion of a 1:150 Toyota Probox car model once again demonstrating these skills with casual ease.

We previously covered such conversions, with another recent one in 2024 involving another 1:150 scale model. That particular one demonstrated driving around on scale model roads, which shows a good practical use of this conversion if you want to have e.g. a scale model town with cars that actually drive around.

In the video you can see how first the base of the scale model has a tiny 25 mAh Li-polymer battery installed, along with two motors, one for steering and one for driving using a rod-linkage system and a lead screw.

The tiny gears used were salvaged from mechanical watches, with photoreflectors keeping track of the driving and steering positions. Remote control is done by infrared, with a tiny SMD IR receiver module in the car, while charging and programming of the MCU is done via terminals installed on the bottom.

In the final part of the video the car is demonstrated driving around, with working head- and rear lights, as well as blinkers and stop lights, including the top rear one. In the video description links are provided to the various schematics and software on Google Drive for those who are feeling like a fun Sunday afternoon project.

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Repairing A Pair Of Voodoo 2 GPUs For Some SLI Action

June 11, 2026 by Maya Posch 12 Comments

Well there's your problem. (Credit: Bits und Bolts, YouTube) — Well there’s your problem. (Credit: Bits und Bolts, YouTube)

Recently [Bits und Bolts] stumbled over a pair of Dragon 3000 branded 3dfx Voodoo 2 cards in his unfixed cards pile, and decided that the best course of action was to not only fix them, but also run them in SLI for some sweet Unreal Tournament action. Naturally, these cards being in the broken cards pile meant that he first had to figure out why they were broken and fix all issues.

The advantage of having two identical Voodoo 2 cards is of course that any missing components, like some resistors on one card, could be referenced on the other card. Beyond that it was mostly a matter of reflowing clearly corroded pins on the ICs and replacing damaged resistors and resistor arrays before the first tests could be run.

Using the mojo utility it was easy enough to spot that there were still some lingering issues, with clear issues visible in 3D games as well. These were tracked down to a dodgy pin on one of the texture mapping units (TMUs) that needed some more reflowing, and a very sneaky resistor array that was cracked but not obviously so until prodded with a multimeter.

With both cards now making happy noises when individually tested, it was time to go full SLI, fire up the Pentium 2 system and enjoy the glory of 24 MB of VRAM at high resolutions in Unreal Tournament. Considering that the bloke who had sent in these cards had found them while cleaning up a shed, it’s quite amazing how little rework was needed to once again party like it’s 1999.

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An image of the surface of Europa. The top half of the sphere is illuminated with the bottom half dark. The surface is traced with lineae, long lines across its surface of various hues of grey, white, and brown. The surface is a brown-grey, somewhat like Earth's Moon with the highest brightness areas appearing white.

Evidence For Water Vapor Plumes On Europa Vanishes In Re-Analysis

June 11, 2026 by Maya Posch 18 Comments

Unlike on Mars where for decades we have had dozens of orbital and ground-based platforms zipping and scurrying about to prod at every bit of emitted radiation, rock type and twitch of dust devils in its thin atmosphere, for other planets and their moons we have to do a lot more speculative interpretation of data. Such was the case with the presumed existence of water plumes on Jupiter’s moon Europa. These now appear to have been a statistical fluke, per research by [L. Roth] et al. in Astronomy & Astrophysics.

As succinctly summarized in the article on this by [Javier Barbuzano] of Sky and Telescope, the original 2013 finding of said water plumes by the same team was based on faint UV emissions from Europa’s southern hemisphere as captured by the Hubble Space Telescope. However, in more recent captures these emissions were not detected again, leading them to reexamine their original analysis of the 2013 data.

One of the main flaws was in the assumption of where Europe was located on Hubble’s 1,000 x 1,000 resolution detector, with the re-analysis showing that they were off by a couple of pixels. A second flaw was quite understandable as since 2013 we have learned that Europa has a thin hydrogen exosphere which interacts with the Sun’s UV radiation. The resulting scattering induces a UV glow which could be mistaken for UV radiation emanating from the moon’s surface.

Even with this one intriguing feature turning out to be a mirage, it doesn’t make Europa any less interesting as it’s still assumed to have vast liquid water oceans. Along with Uranus’ moon Miranda this makes it very worth it to experience more of the sights and sounds of these alien worlds, whether in person or via our robotic friends.

The Merits Of Comment-Driven Development As Counterweight To TDD

June 11, 2026 by Maya Posch 48 Comments

The world of software has seen many paradigms come and go, all of which were supposed to revolutionize its development. Still, one of the basic tenets in engineering of there being no shortcuts to just doing the work properly also rings true in the field of software engineering: trying to skip ‘nice to haves’ like proper documentation, code formatting, and proper testing inevitably results in developers nervously trying to ignore the looming avalanche of technical and other project debts as they keep piling up.

While Test-Driven Development (TDD) once got praised as the silver bullet, the principle of writing tests before writing code merely postpones the inevitable project collapse. The elephant in the room is that you cannot pass on the basics in engineering and expect to come out fine on the other end. There’s a reason why phrases like “all tests green, successfully failed in production” have become common.

This is where the concept of Comment-Driven Development (CDD) comes into play. What started as a bit of a joke many years ago stuck in my mind and led me to my current approach in software development that tries to effectively mirror solid engineering principles.

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