Mechanical 7-Segment Display Combines Servos And Lego

June 25, 2025 by 4 Comments

If you need a seven-segment display for a project, you could just grab some LED units off the shelf. Or you could build something big and electromechanical out of Lego. That’s precisely what [upir] did, with attractive results.

The build relies on Lego Technic parts, with numbers displayed by pushing small black axles through a large yellow faceplate. This creates a clear and easy to read display thanks to the high contrast. Each segment is made up of seven axles that move as a single unit, driven by a gear rack to extend and retract as needed. By extending and retracting the various segments in turn, it’s possible to display all the usual figures you’d expect of a seven-segment design.

It’s worth noting, though, that not everything in this build is Lego. The motors that drive the segments back and forth are third-party components. They’re Geekservo motors, which basically act as Lego-mountable servos you can drive with the electronics of your choice. They’re paired with an eight-channel servo driver board which controls each segment individually. Ideally, though, we’d see this display paired with a microcontroller for more flexibility. [upir] leaves that as an exercise for the viewer for now, with future plans to drive it with an Arduino Uno.

Design files are on Github for the curious. We’ve featured some similar work before, too, because you really can build anything out of Lego. Video after the break.

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The Rise And The Fall Of The Mail Chute

June 25, 2025 by 17 Comments

As the Industrial Age took the world by storm, city centers became burgeoning hubs of commerce and activity. New offices and apartments were built higher and higher as density increased and skylines grew ever upwards. One could live and work at height, but this created a simple inconvenience—if you wanted to send any mail, you had to go all the way down to ground level.

In true American fashion, this minor inconvenience would not be allowed to stand. A simple invention would solve the problem, only to later fall out of vogue as technology and safety standards moved on. Today, we explore the rise and fall of the humble mail chute.

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Careful Design Lets 3D Print Emulate Kumiko

June 25, 2025 by 10 Comments

Kumiko is a form of Japanese woodworking that uses small cuts of wood (probably offcuts) to produce artful designs. It’s the kind of thing that takes zen-like patience to assemble, and years to master– and who has time for that? [Paper View] likes the style of kumiko, but when all you have is a 3D printer, everything is extruded plastic.

His video, embedded below, focuses mostly on the large tiled piece and the clever design required to avoid more than the unavoidable unsightly seams without excessive post processing. (Who has time for that?) The key is a series of top pieces to hide the edges where the seams come together. The link above, however, gives something more interesting, even if it is on Makerworld.

[Paper View] has created a kumiko-style (out of respect for the craftspeople who make the real thing, we won’t call this “kumiko”) panel generator, that allows one to create custom-sized frames to print either in one piece, or to assemble as in the video. We haven’t looked at MakerWorld’s Parametric Model Maker before, but this tool seems to make full use of its capabilities (to the point of occasionally timing out). It looks like this is a wrapper for OpenScad (just like Thingiverse used to do with Customizer) so there might be a chance if enough of us comment on the video [Paper View] can be convinced to release the scad files on a more open platform.

We’ve featured kumiko before, like this wood-epoxy guitar,  but for ultimate irony points, you need to see this metal kumiko pattern made out of nails. (True kumiko cannot use nails, you see.)

Thanks to [Hari Wiguna] for the tip, and please keep them coming!

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Minecraft Clone Manages With Nothing But HTML + CSS

June 25, 2025 by 5 Comments

Can a 3D Minecraft implementation be done entirely in CSS and HTML, without a single line of JavaScript in sight? The answer is yes!

True, this small clone is limited to playing with blocks in a world that measures only 9x9x9, but the fact that [Benjamin Aster] managed it at all using only CSS and pure HTML is a fantastic achievement. As far as proofs of concept go, it’s a pretty clever one.

The project consists of roughly 40,000 lines of HTML radio buttons and labels, combined with fewer than 500 lines of CSS where the real work is done. In a short thread on X [Benjamin] explains that each block in the 9x9x9 world is defined with the help of tens of thousands of <label> and <input type="radio"> elements to track block types and faces, and CSS uses that as a type of display filter. Clicking a block is clicking a label, and changing a block type (“air” or no block is considered a type of block) switches which labels are visible to the user.

Viewing in 3D is implemented via CSS animations which apply transforms to what is displayed. Clicking a control starts and stops the animation, resulting in a view change. It’s a lot of atypical functionality for plain HTML and CSS, showing what is possible with a bit of out-of-the-box thinking.

[Simon Willison] has a more in-depth analysis of CSS-Minecraft and how it works, and the code is on GitHub if you want a closer look.

Once you’re done checking that out and hungry for more cleverness, don’t miss Minecraft in COBOL and Minecraft Running in… Minecraft.

Two images side by side. One shows a laptop opened to a map view with a vehicle model showing a vehicles location. A transparent overlay shows various blue-ish buttons for sending commands to the vehicle. The image on the right is of the interior of a Nissan Leaf. Visible are the very edge of the steering wheel, the center dash including the infotainment display, vents, and shifter, and part of the right side of the dash. Passenger and driver legs are just barely visible at the bottom of the image.

Hack Turns Nissan Leaf Into Giant RC Car

June 24, 2025 by 29 Comments

As cars increasingly become computers on wheels, the attack surface for digital malfeasance increases. The [PCAutomotive] group shared their exploit for turning the 2020 Nissan Leaf into 1600 kg RC car at Black Hat Asia 2025.

Starting with some scavenged infotainment systems and wiring harnesses, the group built test benches able to tear into vulnerabilities in the system. An exploit was found in the infotainment system’s Bluetooth implementation, and they used this to gain access to the rest of the system. By jamming the 2.4 GHz spectrum, the attacker can nudge the driver to open the Bluetooth connection menu on the vehicle to see why their phone isn’t connecting. If this menu is open, pairing can be completed without further user interaction.

Once the attacker gains access, they can control many vehicle functions, such as steering, braking, windshield wipers, and mirrors. It also allows remote monitoring of the vehicle through GPS and recording audio in the cabin. The vulnerabilities were all disclosed to Nissan before public release, so be sure to keep your infotainment system up-to-date!

If this feels familiar, we featured a similar hack on Tesla infotainment systems. If you’d like to hack your Leaf for the better, we’ve also covered how to fix some of the vehicle’s charging flaws, but we can’t help you with the loss of app support for early models.

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A map of the United States showing a series of interconnected lines in white, red, orange, yellow, and green to denote fiber optic and electrical transmission lines. Dots of white, orange, and yellow denote the location of the data centers relative to nearby metropolitan centers.

NREL Maps Out US Data Infrastructure

June 24, 2025 by 13 Comments

Spending time as wee hackers perusing the family atlas taught us an appreciation for a good map, and [Billy Roberts], a cartographer at NREL, has served up a doozy with a map of the data center infrastructure in the United States. [via LinkedIn]

Fiber optic lines, electrical transmission capacity, and the data centers themselves are all here. Each data center is a dot with its size indicating how power hungry it is and its approximate location relative to nearby metropolitan areas. Color coding of these dots also helps us understand if the data center is already in operation (yellow), under construction (orange), or proposed (white).

Also of interest to renewable energy nerds would be the presence of some high voltage DC transmission lines on the map which may be the future of electrical transmission. As the exact location of fiber optic lines and other data making up the map are either proprietary, sensitive, or both, the map is only available as a static image.

If you’re itching to learn more about maps, how about exploring why they don’t quite match reality, how to bring OpenStreetMap data into Minecraft, or see how the live map in a 1960s airliner worked.

Digitally-Converted Leica Gets A 64-Megapixel Upgrade

June 24, 2025 by 25 Comments

Leica’s film cameras were hugely popular in the 20th century, and remain so with collectors to this day. [Michael Suguitan] has previously had great success converting his classic Leica into a digital one, and now he’s taken the project even further.

[Michael’s] previous work saw him create a so-called “digital back” for the Leica M2. He fitted the classic camera with a Raspberry Pi Zero and a small imaging sensor to effectively turn it into a digital camera, creating what he called the LeicaMPi. Since then, [Michael] has made a range of upgrades to create what he calls the LeicaM2Pi.

The upgrades start with the image sensor. This time around, instead of using a generic Raspberry Pi camera, he’s gone with the fancier ArduCam OwlSight sensor. Boasting a mighty 64 megapixels, it’s still largely compatible with all the same software tools as the first-party cameras, making it both capable and easy to use. With a  crop factor of 3.7x, the camera’s Voigtlander 12mm lens has a much more useful field of view.

Unlike [Michael’s] previous setup, there was also no need to remove the camera’s IR filter to clear the shutter mechanism. This means the new camera is capable of taking natural color photos during the day.  [Michael] also added a flash this time around, controlled by the GPIOs of the Raspberry Pi Zero. The camera also features a much tidier onboard battery via the PiSugar module, which can be easily recharged with a USB-C cable.

If you’ve ever thought about converting an old-school film camera into a digital shooter, [Michael’s] work might serve as a great jumping off point. We’ve seen it done with DSLRs, before, too! Video after the break.

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