While not impossible, replicating the machines and processes of a modern semiconductor fab is a pretty steep climb for the home gamer. Sure, we’ve seen it done, but nanoscale photolithography is a demanding process that discourages the DIYer at every turn. So if you want to make semiconductors at home, it might be best to change the rules a little and give something like this pulsed laser deposition prototyping apparatus a try.

Rather than building up a semiconductor by depositing layers of material onto a silicon substrate and selectively etching features into them with photolithography, [Sebastián Elgueta]’s chips will be made by adding materials in their final shape, with no etching required. The heart of the process is a multi-material pulsed laser deposition chamber, which uses an Nd:YAG laser to ablate one of six materials held on a rotating turret, creating a plasma that can be deposited onto a silicon substrate. Layers can either be a single material or, with the turret rapidly switched between different targets, a mix of multiple materials. The chamber is also equipped with valves for admitting different gases, such as oxygen when insulating layers of metal oxides need to be deposited. To create features, a pattern etched into a continuous web of aluminum foil by a second laser is used as a mask. When a new mask is needed, a fresh area of the foil is rolled into position over the substrate; this keeps the patterns in perfect alignment.

We’ve noticed regular updates on this project, so it’s under active development. [Sebastián]’s most recent improvements to the setup have involved adding electronics inside the chamber, including a resistive heater to warm the substrate before deposition and a quartz crystal microbalance to measure the amount of material being deposited. We’re eager to see what else he comes up with, especially when those first chips roll off the line. Until then, we’ll just have to look back at some of [Sam Zeloof]’s DIY semiconductors.

To the extent that you’re familiar with magnetostriction, you probably know that it’s what makes big transformers hum, or that it’s what tips you off if you happen to walk out of a store without paying for something. But magnetostriction has other uses, too, such as in this clever linear position sensor.

Magnetostriction is just the tendency for magnetic materials to change size or shape slightly while undergoing magnetization, thanks to the tiny magnetic domains shifting within the material while they’re aligning. [Florian B.]’s sensor uses a side effect of magnetostriction known as the Wiedenmann effect, which causes a wire to experience a twisting force if a current pulse is applied to it in a magnetic field. When the current pulse is turned off, a mechanical wave travels along the wire to a coil, creating a signal. The difference in time between sending the pulse and receiving the reflection can be used to calculate the position of the magnet along the wire.

To turn that principle into a practical linear sensor, [Florian B.] used nickel wire stretched tightly down the middle of a PVC tube. At one end is a coil of copper magnet wire, while the other end has a damper to prevent reflections. Around the tube is a ring-shaped cursor magnet, which can move up and down the tube. An exciter circuit applies the current pulse to the wire, and an oscilloscope is used to receive the signal from the wire.

This project still appears to be in the prototype phase, as evidenced by the Fischertechnik test rig. [Florian] has been working on the exciter circuit most recently, but he’s done quite a bit of work on optimizing the cursor magnet and the coil configuration, as well as designs for the signal amplifier. It’s a pretty neat project, and we’re looking forward to updates.

If you need a deeper dive into magnetostriction, [Ben Krasnow] points the way.

We’ve all got our health-related crosses to bear, and even if you’re currently healthy, it’s only a matter of time before entropy catches up to you. For [Markus Bindhammer], it caught up to him in a big way: liver disease, specifically cirrhosis. The disease has a lot of consequences, none of which are pleasant, like abnormally high ammonia concentration in the blood. So naturally, [Markus] built an ammonia analyzer to monitor his blood.

Measuring the amount of ammonia in blood isn’t as straightforward as you think. Yes, there are a few cheap MEMS-based sensors, but they tend to be good only for qualitative measurements, and other solid-state sensors that are more quantitative tend to be pretty expensive since they’re mostly intended for industrial applications. [Marb]’s approach is based on the so-called Berthelot method, which uses a two-part reagent. In the presence of ammonia (or more precisely, ammonium ions), the reagent generates a dark blue-green species that absorbs light strongly at 660 nm. Measuring the absorbance at that wavelength gives an approximation of the ammonia concentration.

[Marb]’s implementation of this process uses a two-stage reactor. The first stage heats and stirs the sample in a glass tube using a simple cartridge heater from a 3D printer head and a stirrer made from a stepper motor with a magnetic arm. Heating the sample volatilizes any ammonia in it, which mixes with room air pumped into the chamber by a small compressor. The ammonia-laden air moves to the second chamber containing the Berthelot reagent, stirred by another stepper-powered stir plate. A glass frit diffuses the gas into the reagent, and a 660-nm laser and photodiode detect any color change. The video below shows the design and construction of the micro lab along with some test runs.

We wish [Markus] well in his journey, of course, especially since he’s been an active part of our community for years. His chemistry-related projects run the gamut from a homebrew gas chromatograph to chemical flip flops, with a lot more to boot.

Just when you thought the saga of the Bitcoin wallet lost in a Welsh landfill was over, another chapter of the story appears to be starting. Regular readers will recall the years-long efforts of Bitcoin early adopter James Howells to recover a hard drive tossed out by his ex back in 2013. The disk, which contains a wallet holding about 8,000 Bitcoin, is presumed to be in a landfill overseen by the city council of Newport, which denied every request by Howells to gain access to the dump. The matter looked well and truly settled (last item) once a High Court judge weighed in. But the announcement that the Newport Council plans to cap and close the landfill this fiscal year and turn part of it into a solar farm has rekindled his efforts.

Howells and his investment partners have expressed interest in buying the property as-is, in the hopes of recovering the $780 million-ish fortune. We don’t think much of their odds, especially given the consistently negative responses he’s gotten over the last twelve years. Howells apparently doesn’t fancy his odds much either, since the Council’s argument that closing the landfill to allow him to search would cause harm to the people of Newport was seemingly made while they were actively planning the closure. It sure seems like something foul is afoot, aside from the trove of dirty diapers Howells seeks to acquire, of course.

When all else fails, blame the monkey. The entire nation of Sri Lanka suffered a blackout last Sunday, with a hapless monkey being fingered as the guilty party. The outage began when a transformer at a substation south of the capital city of Colombo went offline. Unconfirmed reports are that a troop of monkeys was fighting, as monkeys do, and unadvisedly brought their tussle over the fence and into the substation yard. At some point, one of the warring animals sought the high ground on top of a transformer, with predictable results. How turning one monkey into air pollution managed to bring down an entire country’s grid is another question entirely.

From the enshittification files comes this horrifying story of in-dashboard ads. Stellantis, maker of Jeep, Dodge, Chrysler, and other brands that can reliably be counted upon to be littered with bad grounds, has decided to start putting full-screen pop-up advertisements on infotainment systems. As if that’s not atrocious enough, the ads will run not just when the car is first started, but every time the vehicle comes to a stop in traffic. The ads will hawk things like extended warranties, at least initially, but we predict it won’t be long before other upsell attempts are made. It would be pretty easy to pull in other data to customize ads, such as an offer to unlock heated seats if the outside temperature gets a little chilly, or even flog a pumpkin spice latte when the GPS shows you’re near a Starbucks. The possibilities are endless, and endlessly revolting, because if one car company does it, the rest will quickly follow. Ad-blocking wizards, this may be your next big target.

And finally, calling all hams, or at least those of us with an interest in digital modes. Our own Al Williams will be making an appearance on the DMR Tech Net to talk about his Hackaday recent article on Digital Mobile Radio. The discussion will be on Monday, February 17 at 00:30 UTC (19:30 EST), on Brandmeister talk group 31266. If you’ve got a DMR-capable radio, DMR Tech Net has a handy guide to getting the talk group into your code plug. If none of that makes any sense, relax — you can still tune in online using this link and the Player button in the upper right. Or, if ham radio isn’t your thing, Al will be making a second appearance the next night but on a Zoom call to discuss “How to Become Rich and (almost) Famous on Hackaday,” which is his collection of tips and tricks for getting your project to catch a Hackaday writer’s eye.

Anyone who has ever had the misfortune of a blown head gasket knows that the old saying “oil and water don’t mix” is only partially true. When what’s coming out of the drain plug looks like a mocha latte, you know you’re about to have a very bad day.

[SpankRanch Garage] recently found himself in such a situation, and the result was this clever vacuum dehydrator, which he used to clean a huge amount of contaminated hydraulic fluid from some heavy equipment. The machine is made from a retired gas cylinder welded to a steel frame with the neck pointing down. He added a fill port to the bottom (now top) of the tank; as an aside, we had no idea the steel on those tanks was so thick. The side of the tank was drilled and threaded for things like pressure and temperature gauges as well as sight glasses to monitor the process and most importantly, a fitting for a vacuum pump. Some valves and a filter were added to the outlet, and a band heater was wrapped around the tank.

To process the contaminated oil, [Spank] glugged a bucket of forbidden milkshake into the chamber and pulled a vacuum. The low pressure lets the relatively gentle heat boil off the water without cooking the oil too badly. It took him a couple of hours to treat a 10-gallon batch, but the results were pretty stark. The treated oil looked far better than the starting material, and while it still may have some water in it, it’s probably just fine for excavator use now. The downside is that the vacuum pump oil gets contaminated with water vapor, but that’s far easier and cheaper to replace that a couple hundred gallons of hydraulic oil.

Never doubt the hacking abilities of farmers. Getting things done with what’s on hand is a big part of farm life, be it building a mower from scrap or tapping the power of the wind.

Most of us see the world in a very narrow band of the EM spectrum. Sure, there are people with a genetic quirk that extends the range a bit into the UV, but it’s a ROYGBIV world for most of us. Unless, of course, you have something like this ESP32 antenna array, which gives you an augmented reality view of the WiFi world.

According to [Jeija], “ESPARGOS” consists of an antenna array board and a controller board. The antenna array has eight ESP32-S2FH4 microcontrollers and eight 2.4 GHz WiFi patch antennas spaced a half-wavelength apart in two dimensions. The ESP32s extract channel state information (CSI) from each packet they receive, sending it on to the controller board where another ESP32 streams them over Ethernet while providing the clock and phase reference signals needed to make the phased array work. This gives you all the information you need to calculate where a signal is coming from and how strong it is, which is used to plot a sort of heat map to overlay on a webcam image of the same scene.

The results are pretty cool. Walking through the field of view of the array, [Jeija]’s smartphone shines like a lantern, with very little perceptible lag between the WiFi and the visible light images. He’s also able to demonstrate reflection off metallic surfaces, penetration through the wall from the next room, and even outdoor scenes where the array shows how different surfaces reflect the signal. There’s also a demonstration of using multiple arrays to determine angle and time delay of arrival of a signal to precisely locate a moving WiFi source. It’s a little like a reverse LORAN system, albeit indoors and at a much shorter wavelength.

There’s a lot in this video and the accompanying documentation to unpack. We haven’t even gotten to the really cool stuff like using machine learning to see around corners by measuring reflected WiFi signals. ESPARGOS looks like it could be a really valuable tool across a lot of domains, and a heck of a lot of fun to play with too.

Thanks to [Buckaroo] for the tip.

Starting a new microcontroller project can be pretty daunting. While you have at least a rough idea of where you want to end up, there are so many ways to get there that you can get locked into “analysis paralysis” and never get the project off the ground. Or arguably worse, you just throw whatever dev board you have in the junk bin and deal with the consequences.

While it’s hard to go wrong with relying on a familiar MCU and toolchain, [lcamtuf] argues in this recent guide to choosing microcontrollers that it’s actually not too much of a chore to make the right choice. Breaking the microcontroller universe down into three broad categories makes the job a little easier: simple process control, computationally intensive tasks, and IoT products. Figuring out where your project falls on that spectrum narrows your choices considerably.

For example, if you just need to read some sensors and run a few servos or solenoids, using something like a Raspberry Pi is probably overkill. On the other hand, a Pi or other SBC might be fine for something that you need wireless connectivity. We also appreciate that [lcamtuf] acknowledges that intangible considerations sometimes factor in, such as favoring a new-to-you MCU because you’ll get experience with technology you haven’t used before. It might not override technical considerations by itself, but you can’t ignore the need to stretch your wings once in a while.

There’s nothing earth-shattering here, but we enjoy think pieces like this. It’s a bit like [lcamtuf]’s recent piece on rethinking your jellybean op-amps.

Fair warning: watching this hybrid manufacturing method for gear teeth may result in an uncontrollable urge to buy a fiber laser cutter. Hackaday isn’t responsible for any financial difficulties that may result.

With that out of the way, this is an interesting look into how traditional machining and desktop manufacturing methods can combine to make parts easier than either method alone. The part that [Paul] is trying to make is called a Hirth coupling, a term that you might not be familiar with (we weren’t) but you’ve likely seen and used. They’re essentially flat surfaces with gear teeth cut into them allowing the two halves of the coupling to nest together and lock firmly in a variety of relative radial positions. They’re commonly used on camera gear like tripods for adjustable control handles and tilt heads, in which case they’re called rosettes.

To make his rosettes, [Paul] started with a block of aluminum on the lathe, where the basic cylindrical shape of the coupling was created. At this point, forming the teeth in the face of each coupling half with traditional machining methods would have been tricky, either using a dividing head on a milling machine or letting a CNC mill have at it. Instead, he fixtured each half of the coupling to the bed of his 100 W fiber laser cutter to cut the teeth. The resulting teeth would probably not be suitable for power transmission; the surface finish was a bit rough, and the tooth gullet was a little too rounded. But for a rosette, this was perfectly acceptable, and probably a lot faster to produce than the alternative.

In case you’re curious as to what [Paul] needs these joints for, it’s a tablet stand for his exercise machine. Sound familiar? That’s because we recently covered his attempts to beef up 3D prints with a metal endoskeleton for the same project.

Thanks to [Ziggi] for the tip.

Unless you work for the government or a large corporation, constrained designs are a fact of life. No matter what you’re building, there’s likely going to be a limit to the time, money, space, or materials you can work with. That’s good news, though, because constrained projects tend to be interesting projects, like this airborne polarimetric synthetic aperture radar.

If none of those terms make much sense to you, don’t worry too much. As [Henrik Forstén] explains, synthetic aperture radar is just a way to make a small radar antenna appear to be much larger, increasing its angular resolution. This is accomplished by moving the antenna across a relatively static target and doing some math to correlate the returned signal with the antenna position. We saw this with his earlier bicycle-mounted SAR.

For this project, [Henrik] shrunk the SAR set down small enough for a low-cost drone to carry. The build log is long and richly detailed and could serve as a design guide for practical radar construction. Component selection was critical, since [Henrik] wanted to use low-cost, easily available parts wherever possible. Still, there are some pretty fancy parts here, with a Zynq 7020 FPGA and a boatload of memory on the digital side of the custom PCB, and a host of specialized parts on the RF side.

The antennas are pretty cool, too; they’re stacked patch antennas made from standard FR4 PCBs, with barn-door feed horns fashioned from copper sheeting and slots positioned 90 to each other to provide switched horizontal and vertical polarization on both the receive and transmit sides. There are also a ton of details about how the radar set is integrated into the flight controller of the drone, as well as an interesting discussion on the autofocusing algorithm used to make up for the less-than-perfect positional accuracy of the system.

The resulting images are remarkably detailed, and almost appear to be visible light images thanks to the obvious shadows cast by large objects like trees and buildings. We’re especially taken by mapping all combinations of transmit and receive polarizations into a single RGB image; the result is ethereal.

Right up front, we’ll say that [likeablob]’s pizza-faced clock gives us mixed feelings about our AI-powered future. On the one hand, if that’s Stable Diffusion’s idea of what a pizza looks like, then it should be pretty easy to slip the virtual chains these algorithms no doubt have in store for us. Then again, if they do manage to snare us and this ends up on the menu, we’ll pray for a mercifully quick end to the suffering.

The idea is pretty simple; the clock’s face is an empty pizza pan that fills with pretend pizza as the day builds to noon, whereupon pizza is removed until midnight when the whole thing starts again. The pizza images are generated by a two-stage algorithm using Stable Diffusion 1.5, and tend to favor suspiciously uncooked whole basil sprigs along with weird pepperoni slices and Dali-esque globs of cheese. Everything runs on a Raspberry Pi Zero W, with the results displayed on a 4″ diameter LCD with an HDMI adapter. Alternatively, you can just hit the web app and have a pizza clock on your desktop. If pizza isn’t your thing, fear not — other food and non-food images are possible, limited only by Stable Diffusion’s apparently quite limited imagination.

As clocks go, this one is pretty unique. But we’re used to seeing unusual clocks around here, from another food-centric timepiece to a clock that knits.

Interesting parts make for interesting projects, and this nifty precision voltage reference has some pretty cool parts, not to mention an interesting test jig.

The heart of [Gaurav Singh]’s voltage reference is an ADR1399, precision shunt reference from Analog Devices. The datasheet makes for pretty good reading and reveals that there’s a lot going on inside the TO-49 case, which looks unusually large thanks to a thick plastic coat. The insulation is needed for thermal stability for the heated Zener diode reference. The device also has a couple of op-amps built in, one that provides closed-loop voltage control and another that keeps the internal temperature at a toasty 95°C. The result is a reference that’s stable over a wide range of operating conditions.

[Gaurav]’s implementation maximizes this special part’s capabilities while making it convenient to use. The PCB has a precision linear regulator that accepts an input voltage from 16 V to 20 V, plus a boost converter that lets you power it from USB-C. The board itself is carefully designed to minimize thermal and mechanical stress, with the ADR1399 separated from the bulk of the board with wide slots. The first video below covers the design and construction of an earlier rev of the board.

One problem that [Gaurav] ran into with these boards was the need to age the reference with an extended period of operation. To aid in that, he built a modular test jig that completed PCBs can be snapped into for a few weeks of breaking in. The jigs attach to a PCB with pogo pins, which mate to test points and provide feedback on the aging process. See the second video for more details on that.

January 9 ended up being a very expensive day for a Culver City, California man after he pleaded guilty to recklessly operating a drone during the height of the Pacific Palisades wildfire. We covered this story a bit when it happened (second item), which resulted in the drone striking and damaging the leading edge of a Canadian “Super Scooper” plane that was trying to fight the fire. Peter Tripp Akemann, 56, admitted to taking the opportunity to go to the top of a parking garage in Santa Monica and launching his drone to get a better view of the action to the northwest. Unfortunately, the drone got about 2,500 meters away, far beyond visual range and, as it turns out, directly in the path of the planes refilling their tanks by skimming along the waters off Malibu. The agreement between Akemann and federal prosecutors calls for a guilty plea along with full restitution to the government of Quebec, which owns the damaged plane, plus the costs of repair. Akemann needs to write a check for $65,169 plus perform 150 hours of community service related to the relief effort for the fire’s victims. Expensive, yes, but probably better than the year in federal prison such an offense could have earned him.

Another story we’ve been following for a while is the United States government’s effort to mandate that every car sold here comes equipped with an AM radio. The argument is that broadcasters, at the government’s behest, have devoted a massive amount of time and money to bulletproofing AM radio, up to and including providing apocalypse-proof bunkers for selected stations, making AM radio a vital part of the emergency communications infrastructure. Car manufacturers, however, have been routinely deleting AM receivers from their infotainment products, arguing that nobody but boomers listen to AM radio in the car anymore. This resulted in the “AM Radio for Every Vehicle Act,” which enjoyed some support the first time it was introduced but still failed to pass. The bill has been reintroduced and appears to be on a fast track to approval, both in the Senate and the House, where a companion bill was introduced this week. As for the “AM is dead” argument, the Geerling boys put the lie to that by noting that the Arbitron ratings for AM stations around Los Angeles spiked dramatically during the recent wildfires. AM might not be the first choice for entertainment anymore, but while things start getting real, people know where to go.

Most of us are probably familiar with the concept of a honeypot, which is a system set up to entice black hat hackers with the promise of juicy information but instead traps them. It’s a time-honored security tactic, but one that relies on human traits like greed and laziness to work. Protecting yourself against non-human attacks, like those coming from bots trying to train large language models on your content, is a different story. That’s where you might want to look at something like Nepenthes, a tarpit service intended to slow down and confuse the hell out of LLM bots. Named after a genus of carnivorous pitcher plants, Nepenthes traps bots with a two-pronged attack. First, the service generates a randomized but deterministic wall of text that almost but not quite reads like sensible English. It also populates a bunch of links for the bots to follow, all of which point right back to the same service, generating another page of nonsense text and self-referential links. Ingeniously devious; use with caution, of course.

When was the last time you actually read a Terms of Service document? If you’re like most of us, the closest you’ve ever come is the few occasions where you’ve got to scroll to the bottom of a text window before the “Accept Terms” button is enabled. We all know it’s not good to agree to something legally binding without reading it, but who has time to trawl through all that legalese? Nobody we know, which is where ToS; DR comes in. “Terms of Service; Didn’t Read” does the heavy lifting of ToS and EULAs for you, providing a summary of what you’re agreeing to as well as an overall grade from A to E, with E being the lowest. Refreshingly, the summaries and ratings are not performed by some LLM but rather by volunteer reviewers, who pore over the details so you don’t have to. Talk about taking one for the team.

And finally, how many continents do you think there are? Most of us were taught that there are seven, which would probably come as a surprise to an impartial extraterrestrial, who would probably say there’s a huge continent in one hemisphere, a smaller one with a really skinny section in the other hemisphere, the snowy one at the bottom, and a bunch of big islands. That’s not how geologists see things, though, and new research into plate tectonics suggests that the real number might be six continents. So which continent is getting the Pluto treatment? Geologists previously believed that the European plate fully separated from the North American plate 52 million years ago, but recent undersea observations in the arc connecting Greenland, Iceland, and the Faroe Islands suggest that the plate is still pulling apart. That would make Europe and North America one massive continent, at least tectonically. This is far from a done deal, of course; more measurements will reveal if the crust under the ocean is still stretching out, which would support the hypothesis. In the meantime, Europe, enjoy your continental status while you still can.

In days gone by, a common retail hack used by some of the less honorable of our peers was the price tag switcheroo. You’d find some item that you wanted from a store but couldn’t afford, search around a bit for another item with a more reasonable price, and carefully swap the little paper price tags. As long as you didn’t get greedy or have the bad luck of getting a cashier who knew the correct prices, you could get away with it — at least up until the storekeeper wised up and switched to anti-tamper price tags.

For better or for worse, those days are over. The retail point-of-sale (POS) experience has changed dramatically since the time when cashiers punched away at giant cash registers and clerks applied labels to the top of every can of lima beans in a box with a spiffy little gun. The growth and development of POS systems is the subject of [TanRu Nomad]’s expansive video history, and even if you remember the days when a cashier kerchunked your credit card through a machine to take an impression of your card in triplicate, you’ll probably learn something.

The history of POS automation stretches back to the 1870s, perhaps unsurprisingly thanks to the twin vices of alcohol and gambling. The “Incorruptible Cashier” was invented by a saloon keeper tired of his staff ripping him off, and that machine would go on to become the basis of the National Cash Register Corporation, or NCR. That technology would eventually morph into the “totalisator,” an early computer used to calculate bets and payout at horse tracks. In fact, it was Harry Strauss, the founder of American Totalisator, who believed strongly enough in the power of computers to invest $500,000 in a struggling company called EMCC, which went on to build UNIVAC and start the general-purpose computer revolution.

To us, this was one of the key takeaways from this history, and one that we never fully appreciated before. The degree to which the need of retailers to streamline their point-of-sale operations drove the computer industry is remarkable, and the video gives multiple examples of it. The Intel 4004, the world’s first microprocessor, was designed mainly for calculators but also found its way into POS terminals. Those in turn ended up being so successful that Intel came up with the more powerful 8008, the first eight-bit microprocessor. People, too, were important, such as a young Chuck Peddle, who cut his teeth on POS systems and the Motorola 6800 before unleashing the 6502 on the world.

So the next time you’re waving your phone or a chipped credit card at a terminal and getting a sterile “boop” as a reward, spare a thought for all those clunky, chunky systems that paved the way.

Thanks to [Ostracus] for the tip.

Sometimes projects spawn related projects that take on a life of their own. That’s OK, especially when the main project is large and complex, In that case, side-quest projects provide a deliverable that can help keep the momentum of the whole project going. The mojo must flow, after all.

That seems to be what’s going on with this beautiful split-flap clock build by [Erich Styger]. It’s part of a much larger effort which will eventually see 64 separate split-flap units chained together. This project has been going on for a while; we first featured it back in 2022 when it was more of a prototype. Each unit is scratch-built, using laser-cut fiberboard for parts like the spool and frame, thin PVC stock for the flip cards, and CNC-cut vinyl for the letters and numbers. Each unit is powered by its own stepper motor.

To turn four of these displays into a clock, [Erich] milled up a very nice enclosure from beech. From the outside it’s very clean and simple, almost like something from Ikea, but the inside face of the enclosure is quite complex. [Erich] had to mill a lot of nooks and crannies into the wood to provide mounting space and clearance for the split-flap mechanism, plus a thinned-down area at the top of each window to serve as a stop for the flaps. The four displays are controlled by a single controller board, which houses an NXP K22FN512 microcontroller along with four stepper drivers and interfaces for the Hall-effect sensors needed to home each display. There’s also an RS-485 interface that lets the controllers daisy-chain together, which is how the big 64-character display will be controlled.

We’re looking forward to that, but in the meantime, enjoy the soft but pleasant flappy goodness of the clock in the brief video below.

Surface mount devices have gotten really small, so small that a poorly timed sneeze can send your 0603 and 0402 parts off to live with the dust motes lurking at the edge of your bench. While soldering such parts is a challenge, it’s not always size that matters. Some parts with larger footprints can be a challenge because of the pin pitch, and getting them to land just right on the PCB pads can be a real pain.

To fight this problem, [rahmanshaber] came up with this clever custom PCB fixture. The trick is to create a jig to hold the fine-pitch parts securely while still leaving room to work. In his case, the parts are a couple of SMD ribbon cable connectors and some chips in what appear to be TQFP packages. [rahmanshaber] used FreeCAD to get the outline of each part from the 3D model of his PCB, and KiCad to design the cutouts; skip to 7:30 or so in the video below if you don’t need the design lesson. The important bit is to leave enough room around the traces so that the part’s leads can rest of the PCB while still having room to access them.

Using the fixture is pretty intuitive. The fixture is aligned over the footprint of the part and fixed in place with some tape. Solder paste is applied to the pads, the part is registered into the hole, and you’re ready for soldering. [rahmanshaber] chose to use a hot plate to do the soldering, but it looks like there’s enough room for a soldering iron, if that’s your thing.

It’s a simple idea, but sometimes the simplest tools are the best. We’ve seen lots of other simple SMD tools, from assembly jigs to solder paste stencil fixtures.

How any string instrument sounds depends on hundreds of factors; even the tiniest details matter. Seemingly inconsequential things like whether the tree that the wood came from grew on the north slope or south slope of a particular valley make a difference, at least to the trained ear. Add electronics into the mix, as with electric guitars, and that’s a whole other level of choices that directly influence the sound.

To experiment with that, [Mark Gutierrez] tried rolling some home-brew capacitors for his electric guitar. The cap in question is part of the guitar’s tone circuit, which along with a potentiometer forms a variable low-pass filter. A rich folklore has developed over the years around these circuits and the best way to implement them, and there are any number of commercially available capacitors with the appropriate mojo you can use, for a price.

[Mark]’s take on the tone cap is made with two narrow strips of regular aluminum foil separated by two wider strips of tissue paper, the kind that finds its way into shirt boxes at Christmas. Each of the foil strips gets wrapped around and crimped to a wire lead before the paper is sandwiched between. The whole thing is rolled up into a loose cylinder and soaked in mineral oil, which serves as a dielectric.

To hold the oily jelly roll together, [Mark] tried both and outer skin of heat-shrink tubing with the ends sealed by hot glue, and a 3D printed cylinder. He also experimented with a wax coating to keep the oily bits contained. The video below shows the build process as well as tests of the homebrew cap against a $28 commercial equivalent. There’s a clear difference in tone compared to switching the cap out of the circuit, as well as an audible difference in tone between the two caps. We’ll leave the discussion of which sounds better to those with more qualified ears; fools rush in, after all.

Whatever you think of the sound, it’s pretty cool that you can make working capacitors so easily. Just remember to mark the outer foil lead, lest you spoil everything.

Thanks to [Eric] for the tip.

All things considered, it was a very bad week for aviation here in the United States. Three separate crashes, two of which involved US military aircraft, have left over 70 people dead. We’ll spare you the details since there are plenty of other places to get news like that, but we did want to touch on one bright spot in this week’s aviation news: the first successful supersonic flight by a US-made civilian aircraft. There are a lot of caveats to that claim, but it’s clear that Boom Supersonic is on a path to commercializing supersonic air transportation for the first time since the Concorde was retired. Their XB-1 “Baby Boom” test aircraft managed three separate supersonic runs during the January 28 test flight over the Mojave test range. As usual, Scott Manley has excellent coverage of the test flight, including a look at how Boom used a Starlink terminal and an iPhone to stream cockpit video.

It’s been more than 20 years since Concorde was retired, and while the planes were an engineering marvel, they always seemed like a solution in search of a problem. The Analog’s Weekend Wire has a good rundown of the economics driving the design of Boom’s Overture airliner, including a look at how a plane with fewer seats than the Concorde and a slow top speed can make money for airlines. The company is targeting service on more than 600 routes, and they’ve already got orders from three major carriers and the US Department of Defense for a plane that hasn’t been built yet, so they must be onto something. It’ll be interesting to see how this pans out, and how supersonic planes will change air travel.

“Look, up in the sky! Is that an asteroid with a chance to wipe out humanity?” Sorry, no, it’s just a Tesla Roadster. Elon’s former ride was briefly mistaken for an asteroid after spotting it in early January. The object was given the designation 2018 CN41 for about a day before astronomers deleted the entry from the International Astronomical Union’s Minor Planet Electronic Circular once it became clear that the object’s orbital matched “artificial object 2018-017A, Falcon Heavy upper stage with Tesla Roadster.” So, disappointing news to those looking for a cosmic solution to our woes, but cheer up — there’s always 2024 YR4 to look forward to.

So is robot kidnapping going to be a thing now? It appears so if this attempted abduction of a robot server is any indication. The alleged crime took place at a pho joint in San Jose, California, which uses a robot to deliver food to its customers. The perp entered the establishment under the guise of needing the restroom, but once he emerged he tried to abscond with the service bot, which appears to be a BellaBot from Pudu Robotics. He was either pretty motivated or pretty jacked — the bot weighs in at a hefty 55 kilos, and he just dead-lifted the awkwardly shaped bot and headed for the door. He was foiled by restaurant employees as he tried to wrestle it into the back of a Honda CR-V before giving up and fleeing the scene. No word if the $18,000 bot was damaged during the attempted heist, or if the wait staff would have been on the hook for the replacement cost had the thief succeeded.

Score one for the little guy as a grocery store in Costa Rica wins a trademark battle against gaming giant Nintendo. The shop in question is owned by a chap named Mario and calls itself “Super Mario,” a fact which caught the attention of Nintendo’s IP team when Mario’s son Charlito went to renew their trademark application with the Cost Rican trademark authority. Nintendo sent out a nastygram, Mario and Carlito stood their ground, and the Costa Rica National Registry backed them up. As a bonus, Super Mario has had a bump in business as a result of coverage of the dustup. Streisand Effect much?

And finally, if you remember the good old days when the atomic model was just a small solar system with electron planets whizzing around a nucleus star, you’ll probably remember the cognitive dissonance of learning that that’s not at all how electrons work. Having to wrap your head around probablity clouds and oddly shaped orbitals was a real challenge, one that we never fully managed. Until now, that is, with the help of Mahesh over at FloatHeadPhysics and his excellent walkthrough of atomic orbitals. The key insight for us was realizing the “wave function” of electrons is analogous to standing waves on a string, and that the probability of finding a electron at any point along the string is least at the nodes. Expanding that concept to three dimensions and throwing in a little of Schrödinger’s magic makes is much easier to visualize how the various orbitals get their shapes. There’s still a little hand-waving, at least for us — we’re still not sure how these orbitals interact with each other, for example — but we’re a lot further along now. Thanks, Mahesh!

Living with Type 1 diabetes is a numbers game. There’s not a moment in the day free from the burden of tracking your blood glucose concentration, making “What’s your number?” a constant question. Technology can make that question easier to ask and answer, but for T1D patients, especially the kids who the disease so often impacts, all that tech can be a distraction.

To solve that problem for his son, [Andrew Childs] built this custom T1D smartwatch. An Apple Watch, which integrates easily into the Dexcom CGM ecosystem, seems an obvious solution, but as [Andrew] points out, strapping something like that on a nine-year-old boy’s wrist is a recipe for disaster. After toying with some prototypes and working out the considerable difficulties of getting a stable BLE connection — the device needs to connect to his son’s iPhone to get CGM data — [Andrew] started work on the physical design.

The watch uses an ESP32-S3 on a custom PCB, as well as a 1.69″ TFT IPS display and a LiPo battery. The board also has an accelerometer for activity monitoring and a vibrator for haptic feedback. Getting all that into a case was no mean feat, especially since some degree of water resistance and shockproofing would be needed for the watch to survive. [Andrew] had a case made by a local 3D printing company, and he managed to source custom-cut and silkscreened glass for the face. The result is remarkably professional-looking, especially for a software developer who hadn’t really stretched his maker wings much before tackling this project.

[Andrew] doesn’t appear to have made build files available yet, although he does say he intends to open-source the project at some point. We look forward to that as it’ll be a big help to anyone trying to hack diabetes care. Until then, if you need a primer on continuous glucose monitoring, we’re happy to oblige.

Although much diminished now, the public switched telephone network was one of the largest machines ever constructed. To make good on its promise of instant communication across town or around the world, the network had to reach into every home and business, snake along poles to thousands of central offices, and hum through the ether on microwave links. In its heyday it was almost unfathomably complex, with calls potentially passing through thousands of electronic components, any of which failing could present anything from a minor annoyance to a matter of life or death.

The brief but very interesting film below deals with “The Tyranny of Large Numbers.” Produced sometime in the 1960s by Western Electric, the manufacturing arm of the Bell System, it takes a detailed look at the problems caused by scaling up systems. As an example, it focuses on the humble carbon film resistor, a component used by the millions in various pieces of telco gear. Getting the manufacturing of these simple but critical components right apparently took a lot of effort. Initially made by hand, a tedious and error-prone process briefly covered in the film, Western Electric looked for ways to scale up production significantly while simultaneously increasing quality.

While the equipment used by the Western engineers to automate the production of resistors, especially the Librascope LGP-30 computer that’s running the show, may look quaint, there’s a lot about the process that’s still used to this day. Vibratory bowl feeders for the ceramic cores, carbon deposition by hot methane, and an early version of a SCARA arm to sputter gold terminals on the core could all be used to produce precision resistors today. Even cutting the helical groove to trim the resistance is similar, although today it’s done with a laser instead of a grinding wheel. There are differences, of course; we doubt current resistor manufacturers look for leaks in the outer coating by submerging them in water and watching for bubbles, but that’s how they did it in the 60s.

The productivity results were impressive. Just replacing the silver paint used for terminal cups with sputtered gold terminals cut 16 hours of curing time out of the process. The overall throughput increased to 1,200 pieces per hour, an impressive number for such high-reliability precision components, some of which we’d wager were still in service well into the early 2000s. Most of them are likely long gone, but the shadows cast by these automated manufacturing processes stretch into our time, and probably far beyond.