Bionode Is Hand Truck Transformed Into Mobile Computing Lab

February 26, 2026 by 11 Comments

[Steven K. Roberts] is the original digital nomad, having designed and built mobile computing for his own use since the 80s. His latest project is Bionode, a portable computing lab built into a hand truck that can accommodate a wide spectrum of needs for a person on the go.

Far more than just a portable computer with wheels and a handle, Bionode is an integrated collection of systems with power management, a sensor suite, multiple computers, NAS for storage, networking, video production tools, and even the ability to be solar charged. [Steven] also uses a laptop, and Bionode complements it by being everything else.

If one truly wishes to be mobile and modular as well as effective, then size and weight begins to be just as important as usability. Everything in Bionode has a purpose, and it currently contains a PC with GPU for local AI and machine learning work, a NAS with 14 TB of storage, an Ubuntu machine, a Raspberry Pi 5 running Home Assistant, another Raspberry Pi 5 for development work, a Raspberry Pi 3 for running his 3D printer, and a Raspberry Pi 4 for SDR (software-defined radio) work. A smart KVM means a single keyboard, mouse, and display can be shared among machines as needed and additional hardware in a thoughtful layout makes audio and video projects workable. Everything is integrated with sensors and Home Assistant with local AI monitoring, which [Steven] likes to think of as the unit’s nervous system.

Bionode is therefore more than just a collection of computers crammed into a hand truck; it’s a carefully-selected array of hardware that provides whatever [Steven] needs.

Give it a look if you want to see what such a system looks like when it’s been designed and assembled by someone who’s “been there, done that” when it comes to mobile computing. Bionode would complement something like a mobile workshop quite nicely; something [Steven] has also done before.

Thanks [Paul] for the tip!

The Curse Of The Everything Device

February 26, 2026 by 77 Comments

In theory having a single device that combines the features of multiple dedicated devices is a great idea, saving a lot of space, time and money. However, in reality it mostly means that these features now conflict with each other, force us to deal with more complex devices that don’t last nearly as long, and become veritable vampires for your precious attention.

Whereas in the olden days a phone was just used for phone calls, now it’s also a video and photo camera, multimedia computer, pager, and more, but at any point an incoming phone call can interrupt what you are doing. There’s also always the temptation of doom scrolling on one of the infinite ‘social media’ apps. Even appliances like televisions and refrigerators are like that now, adding ‘smarts’ that also vie for your attention, whether it’s with advertisements, notifications, or worse.

Meanwhile trying to simply do some writing work on your PC is a battle against easy distractions, leading people to flee to the digital equivalent of typewriters out of sheer desperation. Similarly, we increasingly see ‘dumb’ phones, and other single-task devices making a comeback, both as commercial options and as DIY projects by the community.

Are we seeing the end of the ‘everything device’ and the return to a more simple time?

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Easily Replaceable USB-C Port Spawned By EU Laws

February 26, 2026 by 117 Comments

The USB-C port has become a defacto connectivity standard for modern devices, largely supplanting the ugly mess of barrel jacks and micro USB connectors that once cursed us. While their reliability is good, they don’t last forever, and can be a pain to replace in most devices if they do fail. However, a new part from JAE Electronics could change that.

The problem with replacing USB connectors in most hardware is that they’re soldered in place. To swap them out, you have to master both desoldering and soldering leads of a rather fine pitch. It’s all rather messy. In the interest of satisfying the EU’s new Ecodesign for Sustainable Products Regulation (ESPR), JAE Electronics has developed a USB-C connector that’s easier to replace. Rather than being soldered in, the part is simply clamped down on to a printed circuit board with small screws. As the part is torqued down, small gold-plated contacts are compressed into pads on the PCB to make the necessary contact.

The connector is fully compatible with USB 4 version 2.0. (Don’t ask us how they number these things anymore.) It comes in single and dual connector versions, and is capable of USB PD EPR at up to 240 W (5A/48V). The part does have some drawbacks—namely, the footprint of the metal-shelled part is somewhat larger than most soldered USB C connectors. Whether this precludes its use is very much an application-specific matter for product engineers to decide.

In any case, if you find yourself designing hardware with heavily-used USB C ports, you might find this part useful. It’s not widely available yet, but some parts should be landing at Mouser in coming months. We’ve explored some of the ways USB-C connectors can be fouled and damaged before, too. Sound off with your opinions on this new part in the comments.

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The Engineering Of A Jimi Hendrix Performance

February 26, 2026 by 29 Comments

The guitarist Jimi Hendrix had a unique sound which has influenced countless musicians over the decades. He achieved it through mastery not only of his instrument, but of the complex feedback relationship between amplifier, environment, and guitar — coupled with a series of effects pedals including some then-unique ones made for him. Musical commentators have pored over his work for decades, but a recent piece in IEEE Spectrum is particularly interesting as it examines things from a technical perspective.

It centers around an electrical simulation of Hendrix’s effects chain, and makes an assertion that’s obvious on consideration but not the usual take on a Hendrix performance; that in his hands it became a wave synthesizer rather than the instrument itself. Certainly for anyone with an interest in analogue audio electronics as they pertain to musical synthesis it helps in placing the influence of the different circuits on the sound, and in hearing the familiar performances in a new light.

This isn’t the first time we’ve seen someone take a modelling approach to a guitar effects chain, indeed it’s obvious something missing from the work above is the guitar itself.

Header image: Gemeente Rotterdam (Stadsarchief) CC-0.

Taser Chess Teaches Valuable Lessons The Hard Way

February 25, 2026 by 15 Comments

Over the last few centuries, behavioral psychologists have documented all kinds of ways of modifying our actions and the actions of various animals. From the famous Skinner boxes to many modern video game mechanics, animals and humans alike can learn through the addition or subtraction of various rewards and punishments. And it doesn’t only impact simple actions either; [Everything is Hacked] took this idea to the extreme, using painful electric shocks to teach himself to avoid making blunders while playing chess.

This positive punishment system uses a medical device called transcutaneous electrical nerve stimulation (TENS) to deliver an electric shock to the skin. The electrical jolt is routed through a custom-built, conductive chess board where each square is isolated from the others and controlled by its own relay. The pieces are conductive as well, so if one is placed on a square where it shouldn’t go a relay will switch on to quickly provide the behavioral modification. The control logic is provided by a Raspberry Pi running the Stockfish chess engine, and it keeps track of the locations of the positions of all the pieces by using MX switches in the base of each square on the board.

This project took [Everything is Hacked] over a year to get into a working condition, including having to rebuild the entire project twice after mishaps with baggage handling at an airline. But he was able to demo the board to the Open Sauce tech festival and even took it to his local park to play chess with the local hustlers. Unfortunately, he reports that he spent more time reworking and rewiring his board over that year than he did improving his chess game, so unfortunately he still hasn’t been able to win any of his money back yet. Perhaps combining this project with a chess-playing robot would help.

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A rooftop array of solar thermal collectors

The MOST Effective Thermal Mass Works Like A Sunburn

February 25, 2026 by 13 Comments

Way, way back in the days when men wore beards and wide-lapelled suits in exotic colors, only NASA had access to photovoltaics and ‘solar’ meant solar thermal. In those days of appropriate technology, it was thought that the ultimate in thermal mass was a phase-change material– a salt or wax that in melting and re-freezing could hold far more heat than plain rock or water, which were more often used. Well, now that it’s the 21st century, we’ve got something even better. As Ars Technica reports about a recent paper in Science Magazine, Molecular Solar Thermal (MOST) energy storage can blow that old stuff right out of the water.

Molecular energy storage? That’s where the sunburn comes in. A sunburn occurs because proteins in your skin are denatured– kinked, twisted, and knocked out of shape– by ultraviolet light. The researchers realized that those kinky proteins are pretty energetic: like a spring, they’re storing energy in their distorted structure. Even better, certain chemicals, like the pyrimidone in the study, don’t ‘relax’ the way a phase change material does. It’s not a matter of warming up and giving up the energy stored in the molecular structure when cooling down– the energy needs coaxed out, in this case by an acidic solution.

That poses problems for a closed-loop system, since you’d be continuously diluting the pyrimidone with heat-releasing acid and neutralizing base. On the other hand, 1.65 MJ/kg of energy storage is nothing to sneeze at, especially when you’re collecting it with nothing more technically advanced than a fluid running through clear tubing. Conveniently enough, researchers found a way to make this stuff liquid at room temperature.

Comparing the heat in this MOST storage material to electrical potential in a battery is a case of apples and oranges, but in terms of pure energy density the pyrimidone cooked up for the paper is in the same range as Li-Ion batteries. There is some self-discharge, in that the altered “dewar” state of the pyrimidone decays naturally, but with a half-life of upto 481 days, you could imagine storing up a tankful UV-altered pyrimidone all year round to provide your winter’s heat.

There’s not much power making it to surface in the UV, but lower energy photons cannot effect the transition.

It’s not perfect. Right now you get about 20 “charge cycles” before the molecules break down, but then, if you’re using this for seasonal load-spreading, a two-decade service life is nothing to shake a stick at. It’s only collecting energy from the UV range of the spectrum, which is a tiny fraction of the energy from our sun. The quantum efficiency of the molecule is rather poor as well– it takes a lot of photons to get a dewar transition.

With solar photovaltaics being as cheap as they are, thermal builds are few and far between– even solar water heaters are powered by PV these days. Of course if you’re somewhere that doesn’t get much sun, you could always go for wind power instead.

Thanks to [zit] for the tip! If you’ve seen a bright idea in the wild, or have one yourself, our tips line is open rain or shine.

Adding A Panadapter To A Classic Receiver

February 25, 2026 by 10 Comments

There was a time when only the richest ham radio operators could have a radio with a panadapter. Back in the day, this was basically a spectrum analyzer that monitored a broad slice of the receiver’s intermediate frequency so you could see signals on either side of the receiver’s actual frequency. Today, with SDR technology and computers, this is an easy thing for receivers to implement. But what if you want to refit a classic radio? It isn’t that hard, and [Mirko Pavleski] shares his notes on how he tackled the project. You can also check it out in the video below.

The plan is simple. A FET amplifier taps the radio’s IF stage before the first IF filter. This provides good isolation and buffering. Then, an emitter follower stage provides a matched output to the SDR through a low-pass filter. The SDR remains tuned to the IF frequency, of course. The rest is essentially software and procedures.

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