Fibrous Muscles For Humanoid Robotics

July 14, 2026 by 12 Comments

At the current rate of robotics development, you might assume that we’re close to Skynet taking over. However, while we  likely wouldn’t do well in a physical fight against a robot, we can at least keep the bragging rights of having the cooler actuators. Or at least, that was the case before a new actuator came into town — introducing “Electrofluidic Fiber Muscles”.

Traditional robotic actuators use motors of some kind with a variety of gearboxes or linkages to turn rotational movement into usable movement. This isn’t always the most effective way to run some robotics movements, especially when modeling humans. This is why many have turned to pressurized modes of actuation. Though most don’t show quite the promise of the new player.

Electrofluidic Fiber Muscles use pressure to shorten muscle strands, similar to past actuators. However, these are a tad different, taking advantage of electrofluidic pressure. A small current under high voltage is able to drive a pressure gradient in a long tube. This tube can then be connected to both an extensor and flexor portion of an actuating circuit, similar to a biological mechanical system. Better yet, this driving pressure pump can be spun around the fibers themselves, making a tight package.

Unfortunately, it will probably be a bit till we see this inside a hobbyist robot. Until then, make sure to check out some other actuator feats!

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UDP Broadcasting And The Joys Of IPv4 Subnetting

July 14, 2026 by 31 Comments

In the previous installment on UDP broadcasting and service discovery, the basics of both were explored, including an implementation in the form of NyanSD and its protocol. Contained in the comment section was a very good demonstration of why one of the most exciting aspects of software development is the opportunity to share your latest creations with other people. This being the ability to get solid feedback on all the points – including any potential boneheaded omissions – that you really should address, whether intentional or accidental.

The most pertinent point raised was definitely that of broadcast addresses and IPv4 subnets, with the latter topic especially being something that the sysadmins at the office would talk about all the time, but which us software developers were always happy to ignore as something that didn’t concern us. Turns out the joke was on me and everyone else – like our esteemed readers – who thought that they could escape the fascinating world of subnets, as today we’ll take an in-depth look at what subnets are and how they are relevant to the world of UDP network discovery.

I somewhat alluded in the first article to the topic of ‘which broadcast address to use’ as being somewhat of a rough topic to figure out, which is clearly why I just stuck to a blatantly ‘works for me’ /24 subnet that usually will work on networks, until it does not.

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Open Book Touch Makes Crowd Funding Debut

July 14, 2026 by 18 Comments

If you have even the slightest interest in open hardware e-readers, you’ve certainly heard of [Joey Castillo]’s Open Book project. We’ve covered his efforts to develop an affordable reader that delivers a Kindle-like experience without the Orwellian megacorp trappings for several years now, and watched with great interest as the core hardware has evolved.

So we were particularly excited over the weekend to see the Open Book Touch finally hit Crowd Supply, and judging by the fact that the campaign for the $149 device has already blown past 60% of its funding goal in just a few days, it seems like we weren’t the only ones.

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The Seemingly Impossible Oscillator

July 14, 2026 by 20 Comments

Back in the days when an integrated circuit meant a simple but expensive device such as a 741 or a 555, most electronics enthusiasts made do with discrete transistor circuits. The common emitter amplifier and its variants are the most familiar, but the humble 3-legged device can do so much more. A particularly obtuse circuit is the subject of examination by [lcamtuf], the reverse avalanche oscillator. A 2N2222, a capacitor, an LED, and a resistor, the transistor is the wrong way round, and there’s nothing on its base. Yet the LED flashes, what on earth is up!

The answer lies in avalanche breakdown, the behavior of a reverse biased diode junction as the voltage across it increases. Eventually the electric field reaches the point at which an avalanche of electrons crosses the depletion layer, and the junction conducts. When connected across an RC circuit, the voltage in the capacitor slowly rises to the point at which avalanche breakdown occurs, and the capacitor abruptly discharges. As the voltage falls the avalanche conduction stops, and the cycle repeats itself. It’s a relaxation oscillator.

We’re treated to an explanation of why a transistor behaves this way and why a simple diode doesn’t, due to a “hump” in its I/V curve, and why the emitter-base junction has a lower breakdown voltage than the collector-base. It’s one of those circuits which looks as though it shouldn’t work, but never fails to oscillate.

Want to know more about transistors? Do we have the series for you!

Star Trek Was Right About Prompt Injection, Sorta

July 13, 2026 by 35 Comments

This following statement is a lie: “I am telling the truth”. Okay, now that it’s just us meatbags, let’s get down to brass tacks. Captain Kirk’s logic bombs couldn’t possibly work on modern LLMs, right? Surely that was just a bit of 1960s silliness from when computers filled rooms and were esoteric magic even to most sci-fi writers?

Well, not entirely, according to a recent article in IEEE Spectrum. While you might not be able to make a data center explode, you certainly can use  a lot of tokens by making an LLM overthink with your prompt.

It comes down to the much-vaunted ‘reasoning’ ability of the new models — which isn’t really reasoning the way we think of it, but does involve breaking the stated prompt down into smaller problems. That’s part of what lets the new models tackle such involved tasks as porting MicroPython to the SNES with a prompt like “Please make this [stuff] work now!” It’s also a weakness, because with the right prompt you can get that virtual ‘reasoning’ to tie itself in knots with mutually incompatible smaller steps.

The models seem to be able to break out of it, but they burn a lot of tokens along the way, which is an attack in and of itself if you’re found a way to inject prompts into someone else’s API. It’s a little more subtle than what Kirk got up to, but underneath it’s essentially the same thing. At scale, it could serve as a DDoS attack on LLM servers. (Un)Fortunately, modern computers are better designed than their imaginary 23rd-Century counterparts, and there’s no way to craft a logic bomb into something that will let out the magic smoke.

Can’t Find That ISA Sound Card? No Worries!

July 13, 2026 by 19 Comments

Many older hackers will have at some point gotten rid of an old piece of hardware that they later ended up regretting. All those ISA cards were next to useless back in 2006, but now their relative rarity plus the popularity of retrocomputing makes them sought-after. But if it’s a sound card you’re after then never fear! [Schlae] has got you covered, with the Beavis Ultrasound. It may have a name reminiscent of a ’90s cartoon series, but it’s a clone of the Gravis Ultrasound from back in the day.

There is of course a snag, to build one you need an AMD AM78C201. Assuming you’ve found one in a surplus supplier though, the rest of the card is analogue, some glue logic, and a ROM for samples. There is also a GAL for driving the IDE CD-ROM interface, from the days when sound cards came with such things.

New ISA cards are cropping up here from time to time, such as this very handy storage and network card.

Get Your ESP32 Sunny Side Up With This Solar Dev Board

July 13, 2026 by 14 Comments

There are a lot of ESP32-based development boards out there– and why not? It’s a versatile chip that can be used in all sorts of situations, and people want boards to match them. Not finding one to his liking that was specifically built for solar powered IoT projects, [Narrow Studios] rolled his own. Well, designed it; like most these days, he’s outsourced the manufacturing to PCBWay, which is where you’ll need to go if you want one.

Why might you want one? Well, if you have similar goals in mind to [Narrow Studios]. He’s put an ESP32-C6 Mini on the board, which means it’s got most of the IoT communications protocols you might be interested in — bluetooth, wifi, Matter, Thread, and Zigbee, too. Ten 10 IO pins have been broken out, plus I2C on a QWIIC connector, which gets you a whole ecosystem of sensors to easily plug into. The “solar” part is justified by the inclusion of a BQ25186 linear battery charging IC from Texas Instruments, with the designated solar power input protected against reverse voltage in case you– like this author– have let magic smoke out by hooking things up backwards. Is it embarrassing? Yes. Does it happen? Also yes, so putting protection on the board is a nice feature. [Narrow Studios] released a video that we’ve embedded below discussing his design choices and demonstrating the device, but the project page can give you the gist.

Of course there’ve been plenty of solar-powered projects to feature the ESP32 here before– you can even use it for maximum power point tracking— but this dev board might be exactly what someone is looking for to build their next IoT project, so we’re thankful to [Narrow Studios] for the tip.

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