Flexible Actuator Flaps For 100,000,000 Cycles Without Failure

June 1, 2023 by 23 Comments

Flexible PCBs are super-useful things, but they can have a limited fatigue life. [Carl Bugeja] has been using them to create flexible actuators, though, and he’s getting an amazing 100,000,000 cycles out of them after some rigorous development.

[Carl] explores all manner of optimizations to his flippy actuators in the video. He tried making them oscillate faster by putting a hole in the middle to reduce drag. Other tricks include getting the arm thickness just right, and experimenting with rigidity through adding or removing sections of soldermask.

Fundamentally, though, he learned the key to longevity laid in the copper traces on the flex PCBs themselves. After enough flexural cycles, the traces would fail, killing the actuator. He experimented with a variety of solutions, eventually devleoping a ruggedized two-arm version of his actuator. Twenty samples were put to the test, oscillating at 25 Hz for two weeks straight. All samples survived the test, in which they were put through around 107,820,000 cycles.

[Carl] has put in plenty of hard work on this project, and his actuators have come a long way since we saw them last. He hopes to use the better actuators to improve his FlexLED display. Video after the break.

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Hackaday Prize 2023: Building A Relay ALU

June 1, 2023 by 9 Comments

There’s much truth in the advice that, to truly understand something, you need to build it yourself from the ground up. That’s the idea behind [Christian]’s entry for the Re-engineering Education category of the 2023 Hackaday Prize. Built as an educational demonstrator, this is a complete arithmetic-logic unit (ALU) using discrete relays — and not high-density types either — these are the big honking clear-cased kind.

The design is neatly, intentionally, partitioned along functional lines, with four custom PCB designs, each board operating on 4-bits. To handle a byte-length word, boards are simply cascaded, making a total of eight. The register, adder, logic function, and multiplex boards are the heart of the build with an additional two custom boards for visualization (using an Arduino for convenience) and IO forming the interface. After all, a basic CPU is just an ALU and some control around it, the magic is really in the ALU.

The fundamental logical operations operating upon two operands, {A, B} are A, ~A, B, ~B, A or B, A and B, A xor B, can be computed from just four relays per bit. The logic outputs do need to be fed into a 7-to-1 bit selector before being fed to the output register, but that’s the job of a separate board. The adder function is the most basic, simply a pair of half-adders and an OR-gate to handle the chaining of the carry inputs and generate the carry chain output.

3D printed cable runs are a nice touch and make for a slick wiring job to tie it all together.

For a more complete relay-based CPU, you could check out the MERCIA relay computer project, not to mention this wonderfully polished build.

 

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Books You Should Read: Red Team Blues

June 1, 2023 by 12 Comments

Martin Hench really likes playing on the Red Team — being on the attack. He’s a financial geek, understands cryptocurrency, understands how money is moved around to keep it hidden, and is really good at mining data from social media. He puts those skills together as a forensic accountant. Put simply, Martin finds money that people want hidden. Against his better judgment, Marty does the job of a lifetime, and makes an absolute mint. But that job had hair, and he’s got to live through the aftermath. It turns out, that might just be a challenge, as three separate groups want a piece of him.

Red Team Blues, a work of fiction by [Cory Doctorow] about cryptocurrency, trust, finance, and society as a whole. When [Doctorow] offered to send us a copy to review, we jumped at the chance, and can give it a hearty recommendation as a fun and thoughtful tale. The moral seems to be that while everyone plays the sordid finance game, the government should really work harder to disentangle the mess, but maybe we would do better if more people opted for integrity. There is also a real point to be made about the dark side of cryptocurrency, in that it enables crime, ransomware, and money laundering on a global scale. For all the pluses for privacy and anonymity, there’s some real downsides. The characters spend most of the book wrestling with that dichotomy in the background.

The book took something of a moralizing turn just over halfway through. Which, depending on your viewpoint, you’ll either really appreciate, or have to hold your nose a bit to get through. But the suspense pulls the reader through it, making for an overall enjoyable read. As an added bonus, you might end up with a better mental image of how the pieces of digital privacy, finance, and the real world all fit together.

The book has all the fun references to Tor, Signal, Bitcoin, and computer history you could want. And the central MacGuffin is an interesting one: a cryptocurrency that runs on proof-of-secure-enclave, eliminating the ridiculous power consumption of proof-of-work schemes. All of this with some rich Silicon Valley lore setting up the background. Our conclusion? Two wrenches up.

Old Clock Transformed Into Mesmerizing Light Display

June 1, 2023 by 4 Comments

It’s easy to find a cheap clock at any dollar store that will manage to tell the time, but chances are that the plastic-fantastic construction won’t do you any aesthetic favors. Fear not, though, for [ROBO HUB]’s upcycled design turns a humble clock into a mesmerizing horological display of beauty.

The build starts by scavenging the movement out of a cheap plastic clock. A CD is then glued to the front of the movement to serve as a reflective backing plate. For numerals, the clock uses F3, F6, F9, and F12 keys nabbed from a keyboard.

The real party trick, though, is in the lighting. This build is elevated beyond hackneyed 90s desk clocks by the inclusion of a ring of LED strip lighting. When switched on, the LED light reflects and refracts on the surface of the CD, creating a mesmerizing shifting pattern featuring all the colors of the rainbow.

CDs are actually quite magical from an optical perspective and have all kinds of nifty uses.

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Farewell American Computer Magazines

June 1, 2023 by 80 Comments

I grew up in a small town with a small library. The next town over had what I thought at the time was a big library, but it was actually more like my town had a tiny library, and the next one over had an actual small library. When I left to go to University, I found out what a real library looked like, and I was mesmerized. Books! Lots of books, many of them written in the current decade. My grades probably suffered from the amount of time I spent in the library reading things that didn’t directly relate to my classes. But there was one thing I found that would turn out to be life-changing: A real computer magazine. Last month, Harry McCracken pointed out that the last two widely-distributed American consumer computer magazines ceased paper publication. It is the end of an era, although honestly, it is more like a comatose patient expiring than a shocking and sudden demise.

Dr. Dobb’s first issue was far from the slick commercial magazine it would become.

Actually, before I had gone to college, I did have a subscription to Kilobaud, and I still have some copies of those. No offense to Wayne Green, but Kilobaud wasn’t that inspiring. It was more an extension of his magazine “73”, and while I enjoyed it, it didn’t get me dreaming. Dr. Dobb’s Journal — the magazine I found in the stacks of my University’s library — was tangibly different. There was an undertone of changing the world. We weren’t sure why yet, but we knew that soon, everyone would have a computer. Maybe they’d balance their checkbook or store recipes. A few people already saw the potential of digital music reproduction, although, I must admit, it was so poor at the time, I couldn’t imagine who would ever care.

I say it was life-changing to discover the few issues of Dr. Dobb’s that were published back then because I would go on to contribute to Dr. Dobb’s throughout its storied history. I wrote the infamous DOS extender series, produced special issues, and, when it went mostly digital, was the embedded system blogger for them for more years than I care to admit. In fact, I have the dubious distinction of having the final blog posted; although the website has suffered enough bit rot, I’m not sure any of it has survived other than, maybe, on the Wayback machine. While I wasn’t with the magazine for its entire 38-year run, I read it for at least 35 and had some function there for about 24 of those.

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Getting A Close-Up View Of Chip Formation With An SEM

June 1, 2023 by 16 Comments

When all you’ve got is a hammer, everything looks like a nail. And when you’ve got a scanning electron microscope, everything must look like a sample that would be really, really interesting to see enlarged in all its 3D glory. And this is what [Zachary Tong] delivers with this up close and personal look at the chip formation process.

We’ve got to hand it to [Zach] with this one, because it seems like this was one of those projects that just fought back the whole time. Granted, the idea of cutting metal inside the vacuum chamber of an SEM seems like quite an undertaking right up front. To accomplish this, [Zach] needed to build a custom tool to advance a cutting edge into a piece of stock by tiny increments. His starting point was a simple off-the-shelf linear stage, which needed a lot of prep work before going into the SEM vacuum chamber. The stage’s micrometer advances a carbide insert into a small piece of aluminum 50 microns at a time, raising a tiny sliver of aluminum while it slowly plows a tiny groove into the workpiece.

Getting the multiple shots required to make a decent animation with this rig was no mean feat. [Zach]’s SEM sample chamber doesn’t have any electrical connections, so each of the 159 frames required a painstaking process of advancing the tool, pulling down a vacuum in the chamber, and taking a picture. With each frame taking at least five minutes, this was clearly a labor of love. The results are worth it, though; stitched together, the electron micrographs show the chip formation process in amazing detail. The aluminum oxide layer on the top of the workpiece is clearly visible, as are the different zones of cutting action. The grain of the metal is also clearly visible, and the “gumminess” of the chip is readily apparent too.

For as much work as this was, it seems like [Zach] had things a bit easier than [Ben Krasnow] did when he tried something similar with a much less capable SEM.

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TinyTendo Is A Miniscule Yet Real NES

June 1, 2023 by 3 Comments

These days, it’s possible to get a single-board computer the size of a stick of gum. This will give you the power to emulate thousands of games and you can run one off batteries inside a handheld of your own devising. [Redherring32] took an altogether more creative and old-school approach with the TinyTendo, however. This is one pocket-sized NES that actually runs on genuine hardware. (Nitter)

The feat was achieved by drastically reducing the size of the original NES hardware to make it fit into a Game Boy style form factor. Key to this work was creating a custom cut-sized motherboard which uses original Nintendo DIP chips that have been machined down to become more like QFN-style surface mount packages. With that done, the chips can be assembled onto the TinyTendo PCB which is even smaller than a contemporary Raspberry Pi 3. It’s all assembled in a custom case, with USB C for charging and a bright and colorful LCD screen.

The TinyTendo is designed to use mini-cartridges created by [Bucket Mouse], a hacker who’s no stranger to impressive custom Game Boy hardware. By virtue of running genuine NES hardware, there’s also the possibility that the TinyTendo could play full-sized NES carts with a simple adapter.

This project has been a long time in the making; we first looked at [Redherring32]’s efforts back in 2021. It begs the question why the original NES was so big when Nintendo clearly had plenty of space to spare in those hefty DIP packages! It’s amazing what can be done with some creativity and perseverance. Continue reading “TinyTendo Is A Miniscule Yet Real NES” →