Slightly Sentient D20 Might Subtly Shift Your Rolls

May 25, 2026 by Donald Papp 1 Comment

A twenty-sided die (d20) is a common thing in tabletop gaming, and [kati]’s slightly sentient d20 is a PCB that not only delivers random results on demand, but responds to hot and cold streaks and may even tweak the results a little to reflect its mood.

On its face the unit is a touch-sensitive PCB with twenty small charlieplexed LEDs around its perimeter, one for each die result. When activated by a touch on the center pad, the die dutifully animates a die roll and delivers a result. But something happens if the RNG (random number generator) coughs up results that are unusually lucky, or unlucky.

After a streak of natural 1s, the device gets cranky. It begins to ignore the occasional activation input, and may glitch before a roll, reflecting a low mood. In addition, future rolls while in a low mood have a slight chance of being silently discarded and re-rolled into a low range (1-6), prolonging the unlucky streak. The inverse is true of a die that encounters a lucky run of natural 20s, with the die’s mood shifting to high spirits and having a slight chance of re-rolling future results into a high range (16-20).

The idea is to create (and feed) the feeling of lucky and unlucky streaks. Gamers are of course perfectly capable of projecting such feelings all on their own, which means the die acts as both mirror and amplifier of these emotions. In addition, each die acts slightly differently as a result of being imprinted with different RNG seeds, timing values, and response times which makes each one feel unique. There are reportedly other hidden features as well.

If you’d like to try making your own, keep an eye on the GitHub repository. The originals have design elements that were heavily personalized for [kati]’s gaming group, so the design files are in the process of being turned into a meaningful public release. Of course, there’s more than enough detail already to roll your own if you are so inclined.

Adorable ASCII Aquarium Lives On Your Desk

May 24, 2026 by Donald Papp 19 Comments

[Kert Gartner]’s ASCII Aquarium turns a cheap yellow display (CYD) into a tiny simulated aquarium, complete with ASCII sea creatures each with their own behaviors. There’s all kinds of options and even timekeeping functionality, so the miniature water world can also pull its weight as a desk clock.

The fish and other animal movements are not a series of canned animations; each creature has its own behaviors and responses to things like feeding, which is accomplished by tapping on the screen. A hidden menu offers a wide range of configuration and display options, and there’s even an option to export screen contents as bitmaps.

Add a 3D-printed enclosure and the whole thing looks like a pretty nice weekend project. There’s even a display flip mode, just in case you have a spare 50 mm beamsplitter kicking around.

It’s a very clever use of a CYD that shows how good color and graphics can look when one designs with the hardware’s capabilities (and limitations) in mind.

The CYD is an ESP32-based development board with integrated touchscreen display, and is known for its affordable price and wide availability. This one would look great next to a CYD electric jellyfish.

Extract 3D Video Game Content By Firing Up Photo Mode

May 17, 2026 by Donald Papp 11 Comments

Here’s a pretty clever method [Dung3onlord] used to capture 3D scenes from a PlayStation 5 without needing any specialized software. All that’s needed is a series of high-resolution screenshots, and a few software tools.

The process is essentially photogrammetry, it just uses screenshots as the input instead of photographs.

Instead of sneakily yanking 3D assets from the runtime, he fires up the game’s photo mode on his PS5. By capturing an orbiting video of a static scene (making sure to hide the game’s user interface, something photo mode in games is good for) he ends up with a video file whose content — essentially a series of screenshots — can be used to reconstruct the original 3D scene. The workflow [Dung3onlord] uses has rather more steps, but conceptually that’s all there is to it.

The whole process is remarkably similar to photogrammetry, a method of turning a bunch of photographs from different angles into a 3D point cloud. We’ve seen photogrammetry used to digitize objects because point clouds can be turned into 3D models, essentially allowing one to 3D scan an object using little more than a digital camera.

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Mod This IKEA Lamp Into Smart Lighting For Not A Lot

May 15, 2026 by Donald Papp 14 Comments

The IKEA SKAFTSÄRV is an economical LED accent lamp, but while highly affordable it has only fixed lighting options. [simoneluconi] shows how it can easily be turned into a fully-configurable, WLED-connected, WiFi-enabled RGB lamp with little more than an ESP32-based board.

A thirty-LED lamp with integrated diffusor and stand can be had for surprisingly cheap. Add an equally-economical ESP32 board and it becomes a whole lot more.

To do this, the control board of the lamp gets replaced with an ESP32-C3 Super Mini board. Control and automation comes from WLED, open-source software that offers flexible automation and control for LED lights with a wide range of features, including native Android and iOS apps.

Modifying the SKAFTSÄRV lamp is fairly straightforward, but opening the unit does require breaking some glued seams to get inside. Once that’s done, the replacement board fits nicely into the housing and the unit can be closed back up. As far as WLED is concerned, the new lamp has 30 LEDs, WS281x type, GRB color order.

The end result is a stylish accent lamp with built-in diffusor and mount that can be controlled over WiFi with all the features WLED brings, such as easy integration with Home Assistant.

This isn’t the first time IKEA’s LED lighting has been given a powerup. Their pixel-style LED wall-mounted OBEGRÄNSAD, which displays a few canned animations out of the box, got considerably enhanced with a new controller.

Thanks [Crash] for the tip!

PreFlight Slicer Brings Added Part Strength Feature, And Many More

May 15, 2026 by Donald Papp 38 Comments

Interested in taking some wild new 3D printing features for a test drive? preFlight is a free and open source slicer that brings a host of processing improvements as well as fascinating new features and interesting twists on old ones. There are almost too many to list, so here are a few that caught our eye.

Cross-sectional view of *Interlocking Perimeters*, which increases Z-strength. Unlike brick layers, layer height stays constant.

Want to mix and match different support types on the same object? No problem. How about use Nip & Tuck seams to better hide where layers start and stop? You can emboss images directly onto print surfaces with a real-time preview and use smart bridging for counter-bored holes. We particularly like the ability to preview a sliced object from the side instead of just by layer. That’s not all, either.

Those features alone are pretty intriguing, but there’s one in particular that is particularly relevant to creating stronger parts. Interlocking Perimeters increases layer bonding to increase object strength. Unlike brick layers, which staggers layers vertically, interlocking perimeters plays with spacing and compression to increase bonding in the Z axis while keeping layer heights constant. This is possible thanks in part to the greater control offered by Athena, the new perimeter generator.

There are plenty more features — like a full Python runtime embedded directly into the slicing pipeline, and a host of export pathways — so check out the GitHub repository for added detail and let us know in the comments if you give it a try.

ChargeCap Helps Your Batteries Last Longer By Limiting Charge Level

May 14, 2026 by Donald Papp 22 Comments

If you want to maximize the life of your lithium-ion batteries, proper storage voltage is critical. That is, don’t store them empty, and don’t store them completely full either. “Almost fully charged” is a sweet spot for occasional-use devices. Sadly, this is easier said than done. While many devices use integrated rechargeable batteries these days, most provide no method of limiting charge level. That’s where [DaverDavid]’s ChargeCap comes in.

By sampling charge current and disconnecting when it drops to 50 percent of peak, charging is reliably stopped when the target device is 80 to 90 percent charged, regardless of cell count or capacity.

ChargeCap sits between a USB charger and target device, disconnecting when it detects that recharging is 80 to 90 percent complete. This is particularly useful for maximizing the cell life of devices that see only intermittent use.

The way ChargeCap does this is clever, and relies on the fact that all lithium-ion charging curves look the same regardless of cell capacity or cell count. Charge current remains at pretty much the same level for most of the charging process, but tapers off quickly (and in a linear fashion) as cells approach their maximum capacity. That’s because charging a battery is a lot like blowing up a balloon: the first breaths are easy, but once the balloon fills out, every breath needs to push harder than the last.

ChargeCap works by sampling the peak charge current at the beginning of the charge cycle, then detecting when it drops below 50 percent of peak, at which point charging is stopped. The result is a device that reliably charges to 80 to 90 percent of capacity, and no more. ChargeCap uses an ESP32-C3 and a small OLED display that, as a nice touch, inverts colors to signal charge completion. Design files and code are at the GitHub repository.

Lithium-ion cells are fantastic devices, so flesh out your knowledge by reading [Arya Voronova]’s primer on designing them into your own projects, or a more in-depth explanation of how they work.

FreeCAD 1.1 Tutorial, For Beginners Who Like Clear Instructions

May 13, 2026 by Donald Papp 59 Comments

If you’ve been interested in FreeCAD but haven’t known where to start, here’s a wonderful video tutorial for FreeCAD 1.1 by [Deltahedra] aimed squarely at how to model a 3D part from scratch while also following best engineering practices for part design. It focuses on a concise and meaningful workflow that respects your time and doesn’t make assumptions about skill level. It even starts by taking a few moments to explain how to navigate the interface, a courtesy many will appreciate.

FreeCAD can do quite a lot, so a tutorial that focuses on a specific yet broadly-applicable task with a clear context is a great way to narrow the scope into something manageable, and be comprehensive without getting bogged down in minutiae. [Deltahedra] does this by exclusively using the part design workbench, demonstrating what to do to make a part step-by-step, and showing common mistakes that can happen and how to fix them if they occur. Beyond that, it’s left up to the curious hacker to delve for themselves into what else FreeCAD has to offer.

Since 1.1 is (at this writing) the latest stable release, one can also be confident that the tutorial will match the user interface and features one sees on their own screen. After all, it can be frustrating to attempt to follow a tutorial only to find out things are a few versions behind and nothing is where one expects it to be.

Best practices aren’t just fussy rules about how to do things, and [Deltahedra] demonstrates this by showing how certain procedures just plain make more sense when designing shapes. Our own Arya Voronova has also shared best practices for FreeCAD, so check that out for some added perspective. You’ll be wielding FreeCAD in confidence and comfort in no time.

Thanks for the tip, [Vik Olliver]!

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