Voyager 1 Issue Tracked Down To Defective Memory Chip

April 6, 2024 by 52 Comments

After more than forty-six years all of us are likely to feel the wear of time, and Voyager 1 is no different. Following months of harrowing troubleshooting as the far-flung spacecraft stopped returning sensible data, NASA engineers now feel confident that they have tracked down the cause for the problem: a single defective memory chip. Why this particular chip failed is unknown, but possibilities range from wear and tear to an energetic particle hitting it and disrupting its operation.

We’ve covered the Voyager 1 troubleshooting saga so far, with the initial garbled responses attributed to a range of systems, but narrowed down to the Flight Data Subsystem (FDS), which prepares data for transmission by the telemetry modulation unit (TMU). Based on a recent ‘poke’ command that returned a memory dump engineers concluded that the approximately 3% of corrupted data fit with this one memory chip, opening the possibility of a workaround.

Recently NASA engineers have also been working on patching up the firmware in both Voyager spacecraft, against the background of the dwindling energy produced by the radioisotope generators that have kept both spacecraft powered and warm, even in the cold, dark depths of Deep Space far beyond the light of our Sun.

Linear Feedback Shift Registers For FPGAs

April 6, 2024 by 28 Comments

If you want to start an argument at a Hackaday meeting, you have only to ask something like “How much does this weigh?” or “What time is it?” But if you really want to start a street brawl, you can always say, “Are these numbers random?” Making random numbers that are actually random is actually a tough nut to crack. Most of what we do is, technically, pseudo-random (but we’ll say random number and assume you know what we mean). One way to generate seemingly random sequences is to use a linear feedback shift register or LFSR. You can use LFSRs in software, but they are also very useful in hardware design and [Adam Taylor] takes us through his use of them on FPGAs in a recent post. Continue reading “Linear Feedback Shift Registers For FPGAs” →

3D Printer Hot Off The Griddle

April 5, 2024 by 9 Comments

If you look at [Proper Printing’s] latest video — see below — you’ll immediately get the idea behind his latest printer. There are two heads on two separate gantries, which, of course, opens up many possibilities. But when you think you’ve seen enough, you find out the heated bed is a kitchen griddle, and… well, for us, we had to keep watching.

The heated bed idea was interesting, although the flatness left something to be desired. While it is a simple idea, getting the two gantries to move reliably across the hotbed griddle took a lot of parts and a careful design. We wonder how evenly the griddle heats — ours definitely has hot spots when we cook with it.

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ESP32 Provides Distraction-Free Writing Experience

April 5, 2024 by 23 Comments

Writing out a few thousand words is easy. Getting them in the proper order, now that’s another story entirely. Sometimes you’ll find yourself staring at a blank page, struggling to sieve coherent thoughts from the screaming maelstrom swirling around in your head, for far longer than you’d care to admit. Or so we’ve heard, anyway.

Unfortunately, there’s no cure for writer’s block. But many people find that limiting outside distractions helps to keep the mental gears turning, which is why [Un Kyu Lee] has been working on a series of specialized writing devices. The latest version of the Micro Journal, powered by the ESP32, goes a long way towards achieving his goals of an instant-on electronic notebook.

The writing experience on the Micro Journal is unencumbered by the normal distractions you’d have on a computer or mobile device, as the device literally can’t do anything but take user input and save it as a text file. We suppose you could achieve similar results with a pen and a piece of paper…but where’s the fun in that? These devices are more widely known as writerdecks, which is an extension of the popular cyberdeck concept of hyper-personalized computers.

This newest Micro Journal, which is the fourth iteration of the concept for anyone keeping score, packs a handwired 30% ortholinear keyboard, a 2.8″ ILI9341 240×320 LCD (with SD card slot), ESP32 dev board, and an 18650 battery with associated charging board into a minimalist 3D printed enclosure.

Unable to find any suitable firmware to run on the device, [Un Kyu Lee] has developed his own open source text editor to run on the WiFi-enabled microcontroller. While the distraction-free nature of the Micro Journal naturally means the text editor itself is pretty spartan in terms of features, it does  allow syncing files with Google Drive — making it exceptionally easy to access your distilled brilliance from the comfort of your primary computing device.

While the earlier versions of the Micro Journal were impressive in their own way, we really love the stripped down nature of this ESP32 version. It reminds us a bit of the keezyboost40 and the EdgeProMX, both of which were entered into the 2022 Cyberdeck Contest.

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A Drone Motor Does E-Bikes

April 5, 2024 by 37 Comments

On paper, the motors from both an electric bicycle and a drone can both take about 500 watts or so of power. Of course, their different applications make them anything but equivalent, as the bike motor is designed for high torque at low speed while the drone motor has very little torque but plenty of speed. Can the drone motor do the bike motor’s job? [Pro Know] makes it happen, with a set of speed reducing and torque increasing belts.

The build takes a pretty ordinary bicycle, and replaces the rear brake disk with a large pulley for a toothed belt, which drives a smaller pulley, and through a shaft another set of pulleys to the drone motor. The bracket to hold all this and the very large pulley on the wheel are all 3D printed in PLA-carbon fiber mix.

When it’s assembled, it runs the bike from a small lithium ion pack. That’s not unexpected, but if we’re honest we’d have our doubts as to whether this would survive the open road. It’s evidently a novelty for a YouTube video, and we’d be interested to see how hot the little motor became. However what’s perhaps more interesting is the choice of filament.

Could carbon fibre PLA be strong enough to print a toothed belt pulley? We’d be interested to know more. We saw the same filament combo being tested recently, after all.

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Fictional Computers: The Three Body Problem

April 5, 2024 by 54 Comments

If you intend to see the Netflix series “The Three Body Problem” or you want to read the Hugo-winning story from Chinese author [Cixin Liu], then you should probably bookmark this post and stop reading immediately. There will be some mild spoilers. You have been warned.

While the show does have some moments that will make your science brain cringe, there is one scene that shows a computer that could actually be built. Would it be practical? Probably not in real life, but in the context provided by the show, it was perfectly feasible. It could have, however, been done a little better, but the idea was — like many great ideas — both deceptively simple and amazingly profound. The computer was made of human beings. I’m not talking like Dune’s mentats — humans with super brains augmented by drugs or technology. This is something very different.

Background

This is your last chance. There are spoilers ahead, although I’ll try to leave out as much as I can. In the story, top scientists receive a mysterious headset that allows them to experience totally immersive holodeck-style virtual reality. When they put the headset on, they are in what appears to be a game. The game puts you in a historical location — the court of Henry VIII or Ghengis Kahn. However, this Earth has three suns. The planet is sometimes in a nicely habitable zone and sometimes is not. The periods when the planet is uninhabitable might have everything bursting into flames or freezing, or there might not be sufficient gravity to hold them on the planet’s surface. (Although I’ll admit, I found that one hard to grasp.)

Apparently, the inhabitants of this quasi-Earth can hibernate through the “chaotic eras” and wait for the next “stable era” that lasts a long time. The problem, as you probably know, is that there is no general closed-form solution for the three-body problem. Of course, there are approximations and special cases, but it isn’t easy to make long-term predictions about the state of three bodies, even with modern computers.

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This Week In Security: XZ, ATT, And Letters Of Marque

April 5, 2024 by 11 Comments

The xz backdoor is naturally still the top story of the week. If you need a refresher, see our previous coverage. As expected, some very talented reverse engineers have gone to work on the code, and we have a much better idea of what the injected payload does.

One of the first findings to note is that the backdoor doesn’t allow a user to log in over SSH. Instead, when an SSH request is signed with the right authentication key, one of the certificate fields is decoded and executed via a system() call. And this makes perfect sense. An SSH login leaves an audit trail, while this backdoor is obviously intended to be silent and secret.

It’s interesting to note that this code made use of both autotools macros, and the GNU ifunc, or Indirect FUNCtions. That’s the nifty feature where a binary can include different versions of a function, each optimized for a different processor instruction set. The right version of the function gets called at runtime. Or in this case, the malicious version of that function gets hooked in to execution by a malicious library. Continue reading “This Week In Security: XZ, ATT, And Letters Of Marque” →