Recreating One Of History’s Best Known Spy Gadgets

[Machining and Microwaves] got an interesting request. The BBC asked him to duplicate the Great Seal Bug — the device the Russians used to listen covertly to the US ambassador for seven years in 1945. Turns out they’re filming a documentary on the legendary surveillance device and wanted to demonstrate how it worked.

The strange thing about the bug is that it wasn’t directly powered. It was actually a resonant cavity that only worked when it was irradiated with an external RF energy. Most of the video is background about the bug, with quite a few details revealed. We particularly liked the story of using a software defined radio (SDR) to actually make the bug work.

As you might expect, things didn’t go smoothly. Did they ever get results on camera? Watch the video, and you can find out. This is just the first of six videos he plans to make on the topic, and we can’t wait for future videos that cover the machining and more technical details.

We’ve examined the Theremin bug before. There’s a definite cat-and-mouse dynamic between creating bugging devices and detecting them.

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Single Flex PCB Folds Into A Four-Wheel Rover, Complete With Motors

You’ve got to hand it to [Carl Bugeja] — he comes up with some of the most interesting electromechanical designs we’ve seen. His latest project is right up there, too: a single PCB that folds up into a four-wheel motorized rover.

The key to [Carl]’s design lies with his PCB brushless motors, which he has been refining since we first spotted them back in 2018. The idea is to use traces on the PCB for the stator coils to drive a 3D printed rotor containing tiny magnets. They work surprisingly well, even if they don’t generate a huge amount of torque. [Carl]’s flexible PCB design, which incorporates metal stiffeners, is a bit like an unfolded cardboard box, with two pairs of motor coils on each of the side panels. This leaves the other surfaces available for all the electronics, with includes a PIC, a driver chip, and a Hall sensor for each motor, an IMU and proximity sensor for navigation, and an ESP32 to run the show.

With machined aluminum rotors and TPU tires mounted to the folded-up chassis, it was off to the races, albeit slowly. The lack of torque from the motors and the light weight of the rover, along with some unwanted friction due to ill-fitting joints, added up to slow progress, especially on anything other than a dead flat surface. But with some tweaking, [Carl] was able to get the buggy working well enough to call this one a win. Check out the build and testing in the video below.

Knowing [Carl], this isn’t the last we’ll see of the foldable rover. After all, he stuck with his two-wheel PCB motor design and eventually got that running pretty well. We’ll be keeping an eye out for progress on this one.

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Inside Digital Image Chips

Have you ever thought how amazing it is that every bit of DRAM in your computer requires a teeny tiny capacitor? A 16 GB DRAM has 128 billion little capacitors, one for each bit. However, that’s not the only densely-packed IC you probably use daily. The other one is the image sensor in your camera, which is probably in your phone. The ICs have a tremendous number of tiny silicon photosensors, and [Asianometry] explains how they work in the video you can see below.

The story starts way back in the 1800s when Hertz noticed that light could knock electrons out of their normal orbits. He couldn’t explain exactly what was happening, especially since the light intensity didn’t correlate to the energy of the electrons, only the number of them. It took Einstein to figure out what was going on, and early devices that used the principle were photomultiplier tubes, which are extremely sensitive. However, they were bulky, and an array of even dozens of them would be gigantic.

Semiconductor devices use silicon. Bell Labs was working on bubble memory, which was a way of creating memory that was never very popular. However, as a byproduct, the researchers realized that moving charges around for memory could also move around charges from photosensitive diodes. The key idea was that it was harder to connect many photodiodes than it was to create the photodiodes. Using the charge-coupled device or CCD method, the chip could manipulate the charges to reduce the number of connections to the chip.

CCDs opened up the digital image market, but it has some problems. The next stage was CMOS chips. They’d been around for a while since IBM produced the scanistor, but the sensitivity of these CMOS image chips was poor. Since most people were happy with CCD, there wasn’t as much research on CMOS. However, CMOS sensors would eventually become more capable, and the video explains how it works.

We’ve looked at image sensors before, too. The way you read them can make a big difference in your images.

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How Much Programming Can ChatGPT Really Do?

By now we’ve all seen articles where the entire copy has been written by ChatGPT. It’s essentially a trope of its own at this point, so we will start out by assuring you that this article is being written by a human. AI tools do seem poised to be extremely disruptive to certain industries, though, but this doesn’t necessarily have to be a bad thing as long as they continue to be viewed as tools, rather than direct replacements. ChatGPT can be used to assist in plenty of tasks, and can help augment processes like programming (rather than becoming the programmer itself), and this article shows a few examples of what it might be used for.

AI comments are better than nothing…probably.

While it can write some programs on its own, in some cases quite capably, for specialized or complex tasks it might not be quite up to the challenge yet. It will often appear extremely confident in its solutions even if it’s providing poor or false information, though, but that doesn’t mean it can’t or shouldn’t be used at all.

The article goes over a few of the ways it can function more as an assistant than a programmer, including generating filler content for something like an SQL database, converting data from one format to another, converting programs from one language to another, and even help with a program’s debugging process.

Some other things that ChatGPT can be used for that we’ve been able to come up with include asking for recommendations for libraries we didn’t know existed, as well as asking for music recommendations to play in the background while working. Tools like these are extremely impressive, and while they likely aren’t taking over anyone’s job right now, that might not always be the case.

Gordon Moore, 1929 — 2023

The news emerged yesterday that Gordon Moore, semiconductor pioneer, one of the founders of both Fairchild Semiconductor and Intel, and the originator of the famous Moore’s Law, has died. His continuing influence over all aspects of the technology which makes our hardware world cannot be overstated, and his legacy will remain with us for many decades to come.

A member of the so-called “Traitorous Eight” who left Shockley Semiconductor in 1957 to form Fairchild Semiconductor, he and his cohort laid the seeds for what became Silicon Valley and the numerous companies, technologies, and products which have flowed from that. His name is probably most familiar to us through “Moore’s Law,” the rate of semiconductor development he first postulated in 1965 and revisited a decade later, that establishes a doubling of integrated circuit component density every two years. It’s a law that has seemed near its end multiple times over the decades since, but successive advancements in semiconductor fabrication technology have arrived in time to maintain it. Whether it will continue to hold from the early 2020s onwards remains a hotly contested topic, but we’re guessing its days aren’t quite over yet.

Perhaps Silicon Valley doesn’t hold the place in might once have in the world of semiconductors, as Uber-for-cats app startups vie for attention and other semiconductor design hubs worldwide steal its thunder. But it’s difficult to find a piece of electronic technology, whether it was designed in Mountain View, Cambridge, Shenzhen, or wherever, that doesn’t have Gordon Moore and the rest of those Fairchild founders in its DNA somewhere. Our world is richer for their work, and that’s what we’ll remember Gordon Moore for.

You can read our thoughts on Moore’s famous law. If you ever wondered how Silicon Valley became the place for electronics, the story is probably much older than you think.

A LEGO Camera You Just Might Own Yourself

A camera makes for an interesting build for anyone, because it’s an extremely accessible technology that can be made from materials as simple as cardboard. More robust cameras often require significant work, but what if you could make a usable camera from LEGO? It’s a project taken on by [Zung92], who hasn’t simply made a working 35 mm camera from everyone’s favorite construction toy — he’s also managed to make it exude retro style. Best of all, you can vote for it on the LEGO Ideas website, and you might even get the chance to have one for yourself.

Frustratingly there’s little in the way of in-depth technical detail on the Ideas website, but he does mention that it was a challenge to make it light proof. Even the lens is a LEGO part, and if diffraction-based photography isn’t for you there’s also a pinhole option. We look forward to seeing this camera progress, and we hope we’ll see it advance to becoming a LEGO Ideas kit.

This is an extremely polished design, but surprisingly, it’s not our first LEGO camera.

Thanks [Michael] for the tip.

Clever Mechanism Powers This All-Mechanical Filament Respooler

No matter how far down the 3D printing rabbit hole we descend, chances are pretty good that most of us won’t ever need to move filament from one spool to another. But even so, you’ve got to respect this purely mechanical filament respooler design, and you may want to build one for yourself just because.

We were tipped off to [Miklos Kiszely]’s respooler via the very enthusiastic video below from [Bryan Vines] at the BV3D YouTube channel. He explains the need for transferring filament to another spool as stemming from the switch by some filament manufacturers to cardboard spools for environmental reasons. Sadly, these spools tend to shed fibrous debris that can clog mechanisms; transferring filament to a plastic spool can help mitigate that problem.

The engineering that [Miklos] put into his respooler design is pretty amazing. Bearings excepted, the whole thing is 3D printed. A transmission made of herringbone gears powers both the take-up spool and the filament guide, which moves the incoming filament across the width of the spool for even layers. The mechanism to do this is fascinating, consisting of a sector gear with racks on either side. The racks are alternately engaged by the sector gear, moving a PTFE filament guide tube back and forth to create even layers on the takeup spool. Genius!

Hats off to [Miklos] on this clever design, and for the extremely detailed instructions for printing and building one of your own. Even if you don’t have the cardboard problem, maybe this would help if you buy filament on really big spools and need to rewind for printing. Continue reading “Clever Mechanism Powers This All-Mechanical Filament Respooler”