DOOM Ported To A $30 Clamp Meter

DOOM. Boil it, mash it, stick it in a stew, it’s the game that runs on anything and everything. Now, the classic shooter is running on a rather unlikely target—a cheap clamp meter of very limited resources, thanks to the work of [Artur Bieniek].

The clamp meter in question is the FNIRSI DMC-100, which can be had for the low price of just $30 or so if you know where to look. It’s a far cry from the many thousands of dollars you’d pay for a heavy old 486-based machine back in 1993. [Artur] got the doomgeneric engine running on the Artery AT32F415 chip that runs the clamp meter.

The chip is pretty capable, with its 150 MHz clock speed, though the 32 KB of RAM posed rather a big limitation to the project. It may be one of the lowest RAM DOOM ports out there. Even with this limit, [Artur] was able to get Episode 1 of Freedoom: Phase 1 loaded on to the thing, including E1M1 to E1M9 along with the title screen, intermissions, the finale, the menu, and four save slots. Color graphics are displayed on the meter’s 320 x 240 screen, and there are even sound effects on the built-in buzzer. Controls are mapped to the rather curious choice of a DJI RC-N1 drone controller.

We’ve seen DOOM running on everything from desk phones to completely custom CPUs. These days you have to try pretty hard to find something it hasn’t already been ported to.

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Restoring A Soviet ES-4001 Mainframe Control Panel

Recently the [Chornobyl Family] got their hands on an ES-4001 control panel for a 1970s-era Soviet mainframe, with the intention to restore it to full working order. Not just because they’re really into cool old Soviet technology, but also because of the connection that this control panel holds to the Chernobyl nuclear accident that was so instrumental to the area in modern times.

The Duga-1 computer room with what's left of the ES-1060 mainframe. (Credit: Chornobyl Family, YouTube)
The Duga-1 computer room with what’s left of the ES-1060 mainframe. (Credit: Chornobyl Family, YouTube)

During the 1970s the USSR felt that it could not be left behind in the race to create better digital computers. This led them to not only create a few original designs, but also effectively clone the IBM System/360 and System/370. This resulted in the ES EVM-series of mainframes, with an ES-1060 finding itself installed at the Duga-1 early warning radar system near what is now the Chornobyl nuclear power plant in Ukraine.

Although the radar arrays are the most well-known feature of the Duga-1, below it is the computer center where the ES-1060 was installed. It was never put into service following the ChNPP Unit-4 accident — all that remains of a once pinnacle of Soviet engineering are the picked-over carcass of the mainframe and its control panel.

The control panel in question was obtained was from the early 1980s, serving a more gentle service life in a datacenter and looks to be in a mostly good condition. That said, there was still enough to be done to make it work and undo the damage of its violent removal from the mainframe. Along the way we also learn how the system was used and how the control panel works.

Although similar in some ways to the System/370, it’s still very different, and with only about 300 of these mainframes produced, it’s worth saving whatever elements still remain today, along with the surviving documentation.

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NASA Batteries Survive Extreme Cold And Heat

One of the major limits of mass-produced batteries is the electrolyte. From lead-acid to lithium ion, there’s some temperature where the electrolyte will freeze and cause all sorts of problems, from cracked casings to various non-favorable chemical changes in the battery itself. But if there’ a solid electrolyte available, many of the downsides of charging and discharging batteries in extreme cold disappear. These batteries developed by NASA, for example, can survive some wild temperature swings.

The electrolytes used for these batteries are either a ceramic or polymer electrolyte, both of which are solid. In testing, the batteries could meaningfully operate at temperatures of -60° C and up to 80° C on the high end. Further, the solid electrolyte helps protect them even outside of these temperature ranges. Bringing the battery temperature down to -170° C was not enough to damage the battery at all, and using a small heater to bring the temperature back up to its operating range showed no capacity losses or other issues.

These batteries are eventually intended for use in some of the coldest places outside of Earth still accessible to humans (in theory) such as the south pole of the Moon where the temperatures regularly get that cold and stay cold for long periods, especially in permanently-shadowed craters or places on the Moon we might want to put some telescopes eventually. There are other terrestrial situations where these batteries might be useful as well, since they don’t need as much thermal management as other battery types.

Car’s Camera Footage Backed Up To NAS

For as many sensors, cameras, and computers as there are on modern cars, they ought to be a dream to poke around in and customize to one’s liking. Unfortunately they’re generally plagued by the same locked-down, proprietary software that most consumer electronics ship with, making it very difficult to interact with these systems in ways the manufacturer doesn’t approve of. There are a few exceptions to this rule, though, and [Sasha] built this system which backs up the footage from their electric car’s on-board cameras automatically to a NAS.

The system is built around a Raspberry Pi Zero 2 W which plugs directly into a USB port in the car’s glovebox. To set it up, the software only needs to be flashed onto the Pi and then it can be controlled from a smartphone. It can connect to any NAS over a variety of protocols and keeps track of what footage has been backed up, and can even automatically restart a backup if the car drives away before it has completed. It also automatically frees up space on the car’s internal drives by deleting any files that have already been synced to the NAS. All of the data is kept in the user’s control as well, and nothing leaves the LAN unless the user sets up backups to a cloud service on their own.

If you have the correct electric car and a Pi other than a Zero 2 W, [Sasha] also has a package for other Raspberry Pis that should work. Unfortunately this was designed for a specific electric car; other makes and models won’t work with this out of the box, but we hope that won’t stop others from checking out the GitHub page anyway trying to figure out what’s going on under the hoods of their car’s electrical and computer systems. Sometimes this leads to things you might not expect, like using the car itself as a video game controller.

An Open Source Linear Capacitive Encoder

If you’ve ever pulled apart a set of digital calipers, you’ve probably marvelled at the capacitive encoder that does all the measuring work. There’s nothing stopping you from using the same techniques yourself, as [Nick] demonstrates with an open-source capacitive encoder of his own design.

The sensor PCB works by by having a grid of eight transmitting antennas, etched into a PCB, beneath a larger receiving antenna. The transmitting antennas pulse out a pattern as the sensor PCB moves, with the signals bouncing back from the reflector PCB which is fixed in place. The varying capacitance caused by the position of the reflector elements relative to the sensor PCB varies the strength of the pulses hitting the receiving antenna. A microcontroller—in this case an STM32—can read those pulses to determine the displacement of the sensor PCB relative to the reflector down to a very fine degree. In this case, to an accuracy of 40 micrometers. Not bad!

If you need ultra-fine linear tracking for something you’re building, you might find this project very useful. Files are available on Github for the curious, along with a great explainer on exactly how the capacitive coupling becomes a positional reading. You can also study previous teardowns we’ve featured on cheap digital calipers, just to round out your education further. If you’re working on your own impressive workshop equipment, or subcomponents of such things therein, don’t hesitate to let us know on the tipsline!

Keeping Old Wi-Fi Radios Alive With Stream Conversion

There are plenty of Wi-Fi radios out there that were built over the last two decades or so. However, many older models are now becoming less useful because many internet radio stations are switching to newer streaming formats that they don’t support. [Clifford Farrugia] has been working on a little project to save these appliances from the e-waste bin.

The HLS Radio Converter is the result of that work. It’s a small open-source tool that converts modern HTTP Live Streaming (HLS) protocol streams into regular old HTTP MP3 streams that older internet radio appliances are built to decode. You can run the tool on something as simple as an old Raspberry Pi. To make it work, you just give the tool the URL of the stream you’re looking to convert, and it then spits out a new URL to point your radio to which has the stream in the old-school format instead.

It’s a simple tool, but one that should prove very useful if you have a beloved old internet radio that can’t handle modern streams. We’ve featured lots of fun projects in this vein before, too, like this ultra-tiny internet radio build. If you’re working on your own projects in this space, be sure to let us know via the tipsline.

KiCad… In The Browser?

KiCad is a useful tool for designing printed circuit boards, but it’s of no use to you if you can’t install it on the computer you’re on. To get around that, [Akshay Rukade] has whipped up a browser-based alternative to help keep you working in less permissive environments. It’s called ZiroEDA.

Quite simply, ZiroEDA is a TypeScript port of KiCad 10.0.6’s C++ source code. You get the schematic editor, the PCB editor, the interactive router, and the electrical and design rule checkers all running in a browser. It can open .kicad_pro files as you’d expect, and you can edit and save them as you would if you were working in standard KiCad directly.

[Akshay] reports that KiCad’s own kicad-cli was used for compatibility testing, and that zone fills came out vertex-identical from ZiroEDA versus using KiCad itself. With that said, the project is still a work in progress, and some dialogs from the original software are still missing. Projects are said to be end-to-end encrypted, but you’ll hopefully lose your job quickly if you try and put anything important to national security through a tool like this. You can always try it, just to give your higher-ups a heart attack.

Source is available on GitHub if you want to see how it all ticks. We’ve featured other great KiCad hacks before, too, like this GPU-accelerated autorouter. If you’re working on PCB tools of your own, don’t hesitate to notify the tipsline.