Voyager 1 Issue Tracked Down To Defective Memory Chip

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

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”

ColecoVision Cart Rises From Ashes

We felt bad for [Mark] of Mark Fixes Stuff. Apparently, his house burned down and took virtually everything, including his retrocomputer collection. He did manage to pull out a few things from the remains including a ColecoVision cartridge that was — honestly — melted. We probably would have written it off, but [Mark] was determined to recover something.

He was fortunate that the PCB was not burned, but it was covered in soot and possibly other things. However, the case looked like a chocolate bar left on a dashboard for a few summer days in the tropics.

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The line injector shown characterising the PSRR of an AMS1117 regulator, with a bunch of stuff connected to it through SMA jacks

A Simple Line Injector Shows You The Wonderful World Of PSRR

[limpkin] writes us to show a line injector they’ve designed. The principle is simple — if you want to measure how much PSU noise any of your electronic devices let through, known as PSRR (Power Supply Rejection Ratio), you can induce PSU noise with this board, and then measure noise on your device’s output. The board is likewise simple. A few connectors, resistors, and caps, and a single N-FET!

You do need a VNA, but once you have that, you get a chance to peek into an entire world of insights. Does that 1117 LDO actually filter out noise better than a buck regulator? Is it enough to use a Pi filter for that STM32’s ADC rail, and do the actual parts you’re using actually help with that task? How much noise does your device actually let through in the real world, after being assembled with the specific components you’ve picked? [limpkin] shows us a whole bunch of examples – putting regulators, filters and amplifiers to the test, and showing us how there’s more than meets the eye.

Everything is open source, with full files available on the blog. And, if you want it pre-assembled, tested and equipped with the CNC-milled case, you can get it on Tindie or Lektronz! Of course, even without a tool like this, you can still get good filter designs done with help of computer-aided modelling.

We thank [alfonso] for sharing this with us!

3D Printer Hot Off The Griddle

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

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

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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