Plenty Of LEDs And Useful Too: The 2025 DORS/CLUC Badge

June 1, 2025 by 2 Comments

It’s always nice to see new developments in the world of electronic badges, and while there are events and badge teams pushing the technological envelope there’s still plenty of scope for innovation without too many exotic parts. This year’s DORS/CLUC open source conference in Croatia has just such a badge, with a large alphanumeric LED display as well as USB and an NFC reader. During the conference it displayed the user’s name and could be used in an NFC-based game, but it’s also designed to be used as a general purpose notification device afterwards.

The write-up is familiar to anyone who has been involved with badge production, a tale of long soldering sessions as missing components had to be added later, and of last minute firmware flashing. The heart of the machine is an STM32L073, with an IS31FL3731 LED matrix driver chip and an ST25R3916 for the NFC. All the files can be found in a GitLab repo, and there’s a video below the break showing it all in action.

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Making The Codec Communicator From Metal Gear Solid

June 1, 2025 by 9 Comments

[3DSage] likes building replicas of hardware from movies and video games, often with a functional twist. His latest build aimed to bring the Codec from Metal Gear Solid to life.

If you haven’t played the Metal Gear games, the Codec has been modelled somewhat like an advanced walkie talkie at times, but has often been kept off-screen. Thus, [3DSage] had a great deal of creative latitude to create a realistic-feeling Codec device that provided voice communications and some simple imagery display.

The resulting build relies on an RP2040 microcontroller to run the show. It’s paired with an MPU6050 3-axis gyroscope and accelerometer for motion control of the device’s functionality, and features a small LCD screen to mimic the display in the games. A kids walkie-talkie kit was leveraged for audio communication, but kitted out with a better microphone than standard. Power is via a rechargeable 9V battery, which is really a lithium-ion and USB charging board packed into the familiar 9V form factor.

Where the build really shines, though, is the aesthetic. [3DSage] managed to capture the military-like look and feel as well as authentically recreate the graphics from the games on the screen. The simulated noise on the display is particularly charming. Beyond that, the 3D-printed enclosures leverage texture and multi-color printing really well to nail the fit and finish.

Ultimately, the Codec isn’t much more than a glorified walkie talkie. Even still, [3DSage] was able to create an impressive prop that actually does most of what the device can do in game. If you’ve ever coveted a PipBoy or tricorder, this is one project you’ll be able to appreciate.

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Adaptive Optics Take Clearest Pictures Of The Sun Yet

June 1, 2025 by 9 Comments

It’s sometimes easy to forget that the light in the sky is an actual star. With how reliable it is and how busy we tend to be as humans, we can take that incredible fact and stow it away and largely go on with our lives unaffected. But our star is the thing that gives everything on the planet life and energy and is important to understand. Humans don’t have a full understanding of it either; there are several unsolved mysteries in physics which revolve around the sun, the most famous of which is the coronal heating problem. To help further our understanding a number of scientific instruments have been devised to probe deeper into it, and this adaptive optics system just captures some of the most impressive images of it yet.

Adaptive optics systems are installed in terrestrial telescopes to help mitigate the distortion of incoming light caused by Earth’s atmosphere. They generally involve using a reference source to measure these distortions, and then make changes to the way the telescope gathers light, in this case by making rapid, slight changes to the telescope’s mirror. This system has been installed on the Goode Solar Telescope in California and has allowed scientists to view various solar phenomena with unprecedented clarity.

The adaptive optics system here has allowed researchers to improve the resolution from the 1000 km resolution of other solar telescopes down to nearly the theoretical limit of this telescope—63 km. With this kind of resolution the researchers hope that this clarity will help shine some light on some of the sun’s ongoing mysteries. Adaptive optics systems like this aren’t just used on terrestrial telescopes, either. This demonstration shows how the adaptive optics system works on the James Webb Space Telescope.

Thanks to [iliis] for the tip!

Portal 2 Becomes An Impressively Capable Web Server

June 1, 2025 by 5 Comments

Portal 2 is mostly known as the successful sequel to Valve’s weird physics platformer, Portal. It’s not really known for being a webserver. That might change, though, given the hard work of [PortalRunner].

Quite literally, [PortalRunner] hacked the Source engine and Portal 2 to actually run a working HTTP web server. That required setting up the code to implement a TCP network socket that was suitable for web traffic, since the engine primarily functions with UDP sockets for multiplayer use. This was achieved with a feature initially put in the Source engine for server management in the Left 4 Dead games. From there, the game engine just had to be set up to reply to HTTP requests on that socket with the proper responses a visiting browser expects. If the game engine responds to a browser’s connection request with a bunch of HTML, that’s what the browser will display. Bam! You’ve got a web server running in Portal 2.

From there, [PortalRunner] went further, setting things up so that the status of in-game objects effects the HTML served up to visiting web browsers. Move objects in the game, and the served web page changes. It’s pretty fun, and the complexity and features [PortalRunner] implements only get more advanced from there. When he gets into stacking companion cubes to write HTML in visual form, you’ll want to applaud the Minecraftian glory of it all.

The devil is really in the details on this one, and it’s a great watch. In reality, making Portal 2 into a simple web server is far easier than you might have thought possible. Valve’s physics masterpiece really is popular with hackers; we see it popping up around here all the time. Video after the break.

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Disarming A Nuke… Twice

May 31, 2025 by 26 Comments

Since the tail end of World War II, humanity has struggled to deal with its newfound ability to harness the tremendous energy in the nucleus of the atom. Of course there have been some positive developments like nuclear power which can produce tremendous amounts of electricity without the greenhouse gas emissions of fossil fuels. But largely humanity decided to build a tremendous nuclear weapons arsenal instead, which has not only cause general consternation worldwide but caused specific problems for one scientist in particular.

[Steve Weintz] takes us through the tale of [Dr. John C. Clark] who was working with the Atomic Energy Commission in the United States and found himself first at a misfire of a nuclear weapons test in the early 1950s. As the person in charge of the explosive device, it was his responsibility to safely disarm the weapon after it failed to detonate. He would find himself again in this position a year later when a second nuclear device sat on the test pad after the command to detonate it was given. Armed with only a hacksaw and some test equipment he was eventually able to disarm both devices safely.

One note for how treacherous this work actually was, outside of the obvious: although there were safety devices on the bombs to ensure the nuclear explosion would only occur under specific situations, there were also high explosives on the bomb that might have exploded even without triggering the nuclear explosion following it. Nuclear bombs and nuclear power plants aren’t the only things that the atomic age ushered in, though. There have been some other unique developments as well, like the nuclear gardens of the mid 1900s.

Circuit diagram of linear-feedback shift register.

Can We Replace A Program Counter With A Linear-Feedback Shift Register? Yes We Can!

May 31, 2025 by 32 Comments

Today we heard from [Richard James Howe] about his new CPU. This new 16-bit CPU is implemented in VHDL for an FPGA.

The really cool thing about this CPU is that it eschews the typical program counter (PC) and replaces it with a linear-feedback shift register (LFSR). Apparently an LFSR can be implemented in hardware with fewer transistors than are required by an adder.

Usually the program counter in your CPU increments by one, each time indicating the location of the next instruction to fetch and execute. When you replace your program counter with an LFSR it still does the same thing, indicating the next instruction to fetch and execute, but now those instructions are scattered pseudo-randomly throughout your address space!

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ESPer-CDP Plays CDs And Streams In Style

May 31, 2025 by 12 Comments

What do you get when you combine an ESP32, a 16-bit DAC, an antique VFD, and an IDE CD-ROM drive? Not much, unless you put in the work, which [Akasaka Ryuunosuke] did to create ESPer-CDP, a modern addition for your hi-fi rack.

It plays CDs (of course), but also can also scrobb the disks to Last.fm, automatically fetch track names and lyrics for CDs, and of course stream internet radio. It even acts as a Bluetooth speaker, because when you have an ESP32 and a DAC, why not? Of course we cannot help but award extra style points for the use of a VFD, a salvaged Futaba GP1232A02.  There’s just something about VFDs and stereo equipment that makes them go together like milk and cookies.

close up of front of machine showing VFD.
Between the panel and the VFD, this could almost pass as vintage Sony.

In terms of CD access, it looks like the IDE interface is being used to issue ATAPI commands to the CD-ROM drive to get audio out via S/PDIF.  (Do you remember when you had to hook your CD drive to your sound card to play music CDs?) This goes through a now-discontinued WM8805 receiver — a sign this project has been in the works for a while — that translates S/PDIF into an I2S stream the ESP32 can easily work with.

Work with it it does, with the aforementioned scrobbing, along with track ID and time-sinked lyrics via CDDB or  MusicBrainz. The ESP32 should have the computing power to pull data through the IDE bus and decode it, but we have to admit that this hack gets the job done — albeit at the expense of losing the ability to read data CDs, like MP3 or MIDI. [Akasaka Ryuunosuk] has plans to include such functionality into v2, along with the ability to use a more modern SATA CD-ROM drive. We look forward to seeing it, especially if it keeps the VFD and classic styling. It just needs to be paired with a classic amplifier, and maybe a DIY turntable to top off the stack.

Thanks to [Akasaka Ryuunosuke] for the tip. If you also crave our eternal gratitude (which is worth its weight in gold, don’t forget), drop us a tip of your own. We’d love to hear from you.