Author: Bryan Cockfield

1710 Articles

Before You Sudo Rm -rf /, Take Some Precautions

April 21, 2023 by 40 Comments

Maintaining or administering a computer system remotely is a common enough task these days, but it’s also something that can go sideways on you quickly if you aren’t careful. How many of us are guilty of executing a command, having it fail, and only then realizing that we weren’t connected to the correct computer at all? [Callan] occasionally has this issue as well, but in at least one instance, he deleted all of the contents of the wrong server by mistake. To avoid that mistake again, he uses color codes in the command line in a fairly unique way.

The solution at first seems straightforward enough. Since the terminal he’s using allows for different colors to be displayed for the user and hostname on the bash prompt, different text and background colors are used for each server. The only problem with this is that his friends also have access to these servers, and one of them is red/green colorblind, which led to another near-catastrophic mix-up. To ensure no edge cases are missed, [Callan] built a script which runs on every new server he spins up which selects two random colors, checks that they contrast well with each other, don’t create problems for the colorblind, and then applies them to the bash prompt.

For a problem most of us have had at some point or another, it’s a fairly elegant solution that helps ensure we’re sending the right commands to the right computer. This adds a layer of automation to the process and, while some color combinations do look similar, there are enough to help out most of us in some way, especially since he has released the source code on his GitHub page. For other helpful server administration tips, we’d recommend the Linux-Fu article about deploying your own dynamic DNS.

Getting The Most From Fading ThinkPads

April 21, 2023 by 40 Comments

The ThinkPad line of laptops has been widely prized not only by businesses but also by those who appreciate a high standard of hardware quality and repairability. But some think the cracks are starting to form in their reputation, as it seems that new ThinkPads are sacrificing quality for aesthetics and cost. As a result a huge modding scene has popped up around models that are a few years old like [Cal] found out when working on this X230.

At first he only made some cosmetic improvements to the laptop like replacing the worn palm rest, but quickly found himself in a rabbit hole with other upgrades like swapping out the keyboard and battery. The new keyboard is a 7-row X220 keyboard, which required modification of the connector and flashing the embedded controller with a hacked image to change the keyboard map without needing to make changes at the OS level. From there, he decided to replace the lackluster screen with a 1920×1080 matte IPS panel using an adapter board from Nitrocaster, and finished off his upgrades with a customized Coreboot BIOS for improved performance and security.

While Coreboot doesn’t remove all of the binary blobs that a bootloader like libreboot does, the latter is not compatible with more modern machines like this X230. Still, you’ll get many benefits from using Coreboot instead of the stock bootloader. For running Linux on a daily driver laptop, we appreciate all of these updates and expect that [Cal] will get plenty of years of use out of his machine. We’ve definitely seen an active modding scene for ThinkPads that were (at the time) seven years old and still going strong, so we’d expect nothing less for this one.

MRI Resolution Progresses From Millimeters To Microns

April 20, 2023 by 15 Comments

Neuroscientists have been mapping and recreating the nervous systems and brains of various animals since the microscope was invented, and have even been able to map out entire brain structures thanks to other imaging techniques with perhaps the most famous example being the 302-neuron brain of a roundworm. Studies like these advanced neuroscience considerably but even better imaging technology is needed to study more advanced neural structures like those found in a mouse or human, and this advanced MRI machine may be just the thing to help gain better understandings of these structures.

A research team led by Duke University developed this new MRI technology using an incredibly powerful 9.4 Tesla magnet and specialized gradient coils, leading to an image resolution an impressive six orders of magnitude higher than a typical MRI. The voxels in the image measure at only 5 microns compared to the millimeter-level resolution available on modern MRI machines, which can reveal microscopic details within brain tissues that were previously unattainable. This breakthrough in MRI resolution has the potential to significantly advance understanding of the neural networks found in humans by first studying neural structures in mice at this unprecedented detail.

The researchers are hopeful that this higher-powered MRI microscope will lead to new insights and translate directly into advancements healthcare, and presuming that it can be replicated, used on humans safely, and becomes affordable, we would expect it to find its way into medical centers as soon as possible. Not only that, but research into neuroscience has plenty of applications outside of healthcare too, like the aforementioned 302-neuron brain of the Caenorhabditis elegans roundworm which has been put to work in various robotics platforms to great effect.

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A RISC-V Supercluster For Very Low Cost

April 19, 2023 by 22 Comments

As ARM continues to make inroads in the personal computing space thanks to its more modern and streamlined instruction set architecture (ISA) and its reduced power demands especially compared to x86 machines, the main reason it continues to become more widespread is how easy it is to get a license to make chips using this ISA. It’s still not a fully open source instruction set, though, so if you want something even more easily accessible than ARM you’ll need to find something like these chips running the fully open-source RISC-V ISA and possibly put them to work in a custom supercluster.

[bitluni] recently acquired a large number of CH32V003 microcontrollers and managed to configure them all to work together in a cluster. The entire array is only $2 (not including all of the other components attached to the board) so a cluster of arbitrary size is potentially possible. [bitluni] built a four-layer PCB for this project with an 8-bit bus so the microcontrollers can communicate with each other. Each chip has its own ADC and I/O that are wired to a set of GPIO pins on the sides of the board. The build is rounded out with a USB interface for programming and power.

There were a few quirks to get this supercluster up and running, including some issues with the way the reset and debug pins work on these specific microcontrollers. With some bugs like this out of the way, the entire cluster is up and running, and [bitluni] hints that his design could be easily interfaced with even larger RISC-V superclusters. As for a use for this build, sometimes clusters like these are built just to build them, but since the I/O and ADCs are accessible in theory this cluster could do anything a larger microcontroller might be able to do, only at a much lower price.

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Native Alaskan Language Reshapes Mathematics

April 18, 2023 by 83 Comments

The languages we speak influence the way that we see the world, in ways most of us may never recognize. For example, researchers report seeing higher savings rates among people whose native language has limited capacity for a future tense, and one Aboriginal Australian language requires precise knowledge of cardinal directions in order to speak at all. And one Alaskan Inuit language called Iñupiaq is using its inherent visual nature to reshape the way children learn and use mathematics, among other things.

Arabic numerals are widespread and near universal in the modern world, but except perhaps for the number “1”, are simply symbols representing ideas. They require users to understand these quantities before being able to engage with the underlying mathematical structure of this base-10 system. But not only are there other bases, but other ways of writing numbers. In the case of the Iñupiaq language, which is a base-20 system, the characters for the numbers are expressed in a way in which information about the numbers themselves can be extracted from their visual representation.

This leads to some surprising consequences, largely that certain operations like addition and subtraction and even long division can be strikingly easy to do since the visual nature of the characters makes it obvious what each answer should be. Often the operations can be seen as being done to the characters themselves, instead of in the Arabic system where the idea of each number must be known before it can be manipulated in this way.

This project was originally started as a way to make sure that the Iñupiaq language and culture wasn’t completely lost after centuries of efforts to eradicate it and other native North American cultures. But now it may eventually get its own set of Unicode characters, meaning that it could easily be printed in textbooks and used in computer programming, opening up a lot of doors not only for native speakers of the language but for those looking to utilize its unique characteristics to help students understand mathematics rather than just learn it.

Building An Electron Microscope For Research

April 14, 2023 by 10 Comments

There are a lot of situations where a research group may turn to an electron microscope to get information about whatever system they might be studying. Assessing the structure of a virus or protein, analyzing the morphology of a new nanoparticle, or examining the layout of a semiconductor all might require the use of one of these devices. But if your research involves the electron microscope itself, you might be a little more reluctant to tear down these expensive devices to take a look behind the curtain as the costs to do this for more than a few could quickly get out of hand. That’s why this research group has created their own electron detector.

Specifically, the electron detector is designed for use in a scanning electron microscope, which is typically used for inspecting the surface of a sample and retrieving a high-resolution, 3D image of it compared to transmission microscopes which can probe internal structures. The detector is built on a four-layer PCB which includes the photodiode sensing array, a series of amplifiers, and a power supply. All of the circuit diagrams and schematics are available for inspection as well thanks to the design being licensed under the open Creative Commons license. For any research team looking to build this, a bill of materials is also included, as is a set of build instructions.

While this is only one piece of the puzzle surrounding the setup and operation of an electron microscope, its arguably the most important, and also greatly lowers the barrier of entry for anyone looking to analyze electron microscope design themselves. With an open standard, anyone is free to modify or augment this design as they see fit which is a marked improvement over the closed and expensive proprietary microscopes out there. And, if low-cost microscopes are your thing be sure to check out this fluorescence microscope we featured that uses readily-available parts to dramatically lower the cost compared to commercial offerings.

Low-Cost Display Saved By RP2040

April 14, 2023 by 23 Comments

Anyone looking for components for electronics projects, especially robotics, microcontrollers, and IoT devices, has likely heard of Waveshare. They are additionally well-known suppliers of low-cost displays with a wide range of resolutions, sizes, and capabilities, but as [Dmitry Grinberg] found, they’re not all winners. He thought the price on this 2.8-inch display might outweigh its poor design and lack of documentation, and documented his process of bringing it up to a much higher standard with a custom driver for it.

The display is a 320×240 full-color LCD which also has a touchscreen function, but out-of-the-box only provides documentation for sending data to it manually. This makes it slow and, as [Dmitry] puts it, “pure insanity”. His ultimate solution after much poking and prodding was to bit-bang an SPI bus using GPIO on an RP2040 but even this wasn’t as straightforward as it should have been because there are a bunch of other peripherals, like an SD card, which share the bus. Additionally, an interrupt is needed to handle the touchscreen since its default touch system is borderline useless as well, but after everything was neatly stitched together he has a much faster and more versatile driver for this display and is able to fully take advantage of its low price.

For anyone else attracted to the low price of these displays, at least the grunt work is done now if a usable driver is needed to get them up and running. And, if you were curious as to what [Dmitry] is going to use this for, he’s been slowly building up a PalmOS port on hardware he’s assembling himself, and this screen is the perfect size and supports a touch interface. We’ll keep up with that project as it progresses, and for some of [Dmitry]’s other wizardry with esoteric displays make sure to see what he’s done with some inexpensive e-ink displays as well.