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Hackaday Links: November 24, 2024

25 Noviembre 2024 at 00:00
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We received belated word this week of the passage of Ward Christensen, who died unexpectedly back in October at the age of 78. If the name doesn’t ring a bell, that’s understandable, because the man behind the first computer BBS wasn’t much for the spotlight. Along with Randy Suess and in response to the Blizzard of ’78, which kept their Chicago computer club from meeting in person, Christensen created an electronic version of a community corkboard. Suess worked on the hardware while Christensen provided the software, leveraging his XMODEM file-sharing protocol. They dubbed their creation a “bulletin board system” and when the idea caught on, they happily shared their work so that other enthusiasts could build their own systems.

BBSs were the only show in town for a long time, and the happy little modem negotiation tones were like a doorbell you rang to get into a club where people understood your obsession. Perhaps it’s just the BBS nostalgia talking, but despite the functional similarities to today’s social media, the BBS experience seemed a lot more civilized. It’s not that people were much better behaved back then; any BBS regular can tell you there were plenty of jerks online then, too. But the general tone of BBS life was a little more sedate, probably due in part to the glacial pace of dial-up connections. Even at a screaming 2,400 baud, characters scrolled across your screen slower than you could read them, and that seemed to have a sedating effect on your passions. By the time someone’s opinion on the burning issues of the day had finally been painted on your monitor, you’d had a bit of time to digest it and perhaps cool down a bit before composing a reply. We still had our flame wars, of course, but it was like watching slow-motion warfare and the dynamic was completely different from today’s Matrix.

Speaking of yearning for a probably mythical Golden Age, Casio has announced a smart ring that looks like a miniature version of their classic sports chronograph wristwatch. The ring celebrates Casio’s 50th anniversary of making watches, and features a stainless steel case made by metal injection molding. The six-digit LCD is pretty limited in what it can display, and the ring doesn’t do much other than tell the time and date and sound alarms. So we’re not sure where the smarts are here, except for the looks, of course.

We got a tip recently on a series of really interesting videos that you might want to check out, especially if you’re into EMC simulations. Panire’s channel is chock full of videos showing how to use openEMS, the open-source electromagnetic field solver, with KiCad EDA software to simulate the RF properties of high-speed circuits. He’s got some in-depth videos on getting things set up plus some great tutorials on creating simulations that let you see how your PCB designs are radiating, allowing you to make changes and see the results right away. Very useful stuff, and pretty fun to look at, too.

Here at Hackaday, we get a surprising and disappointingly regular stream of projects that claim to finally have beaten the laws of thermodynamics. So the words “Perpetual Motion” are especially triggering to us, but we instantly put that aside when we saw the title card on this video about the Atmos Clock. No, it’s not perpetual motion, but since as the name suggests, being powered by atmospheric pressure and temperature changes, it’s about as close as you can get. We remember one of these beautiful timepieces on the mantle in our grandparents’ house, gifted to “Grampy” for years of faithful service by his employer. It was a delicate machine and fascinating to watch work, which it only briefly did once we grandkids got near it. Still, watching how the mechanism worked is pretty interesting stuff.

And finally, if you haven’t checked out The Analog, you really should. It’s a weekly newsletter written by our friend Mihir Shah and is full of interesting tidbits from the world of electronics and technology. This time around he gifted us with a video that looks inside optical sorting in food processing. You’ve probably seen these in action before, where cascades of objects — grapes in this case, obviously in a winery — are spread out on a high-speed conveyor belt under the watchful gaze of a computer vision system, which spots the bad grapes and yeets them into oblivion with a precisely controlled jet of compressed air. The mind boggles on the control loops needed to get the jet and the bad grape to meet up at just the right time so that good grapes stay in the game.

Double Your Analog Oscilloscope Fun with this Retro Beam Splitter

24 Noviembre 2024 at 21:00

These days, oscilloscope hacking is all about enabling features that the manufacturer baked into the hardware but locked out in the firmware. Those hacks are cool, of course, but back in the days of analog scopes, unlocking new features required a decidedly more hardware-based approach.

For an example of this, take a look at this oscilloscope beam splitter by [Lockdown Electronics]. It’s a simple way to turn a single-channel scope into a dual-channel scope using what amounts to time-division multiplexing. A 555 timer is set up as an astable oscillator generating a 2.5-kHz square wave. That’s fed into the bases of a pair of transistors, one NPN and the other PNP. The collectors of each transistor are connected to the two input signals, each biased to either the positive or negative rail of the power supply. As the 555 swings back and forth it alternately applies each input signal to the output of the beam splitter, which goes to the scope. The result is two independent traces on the analog scope, like magic.

More after the break…

If you’re wondering how this would work on a modern digital scope, so was [Lockdown Electronics]. He gave it a go with his little handheld scope meter and the results were surprisingly good and illustrative of how the thing works. You can clearly see the 555’s square wave on the digital scope sandwiched between the two different input sine waves. Analog scopes always have trouble showing these rising and falling edges, which explains why the beam splitter looks so good on the CRT versus the LCD.

Does this circuit serve any practical purpose these days? Probably not, although you could probably use the same principle to double the number of channels on your digital scope. Eight channels on a four-channel scope for the price of a 555? Sounds like a bargain to us.

RFID From First Principles and Saving a Cat

24 Noviembre 2024 at 03:00

[Dale Cook] has cats, and as he readily admits, cats are jerks. We’d use stronger language than that, but either way it became a significant impediment to making progress with an RFID-based sensor to allow his cats access to their litterbox. Luckily, though, he was able to salvage the project enough to give a great talk on RFID from first principles and learn about a potentially tragic mistake.

If you don’t have 20 minutes to spare for the video below, the quick summary is that [Dale]’s cats are each chipped with an RFID tag using the FDX-B protocol. He figured he’d be able to build a scanner to open the door to their playpen litterbox, but alas, the read range on the chip and the aforementioned attitude problems foiled that plan. He kept plugging away, though, to better understand RFID and the electronics that make it work.

To that end, [Dale] rolled his own RFID reader pretty much from scratch. He used an Arduino to generate the 134.2-kHz clock signal for the FDX-B chips and to parse the returned data. In between, he built a push-pull driver for the antenna coil and an envelope detector to pull the modulated data off the carrier. He also added a low-pass filter and a comparator to clean up the signal into a nice square wave, which was fed into the Arduino to parse the Differential Manchester-encoded data.

Although he was able to read his cats’ chips with this setup, [Dale] admits it was a long road compared to just buying a Flipper Zero or visiting the vet. But it provided him a look under the covers of RFID, which is worth a lot all by itself. But more importantly, he also discovered that one cat had a chip that returned a code different than what was recorded in the national database. That could have resulted in heartache, and avoiding that is certainly worth the effort too.

Thanks for the tip, [Gustavo].

Close Shave for an Old Oscilloscope Saved with a Sticky Note

23 Noviembre 2024 at 21:00

When you tear into an old piece of test equipment, you’re probably going to come up against some surprises. That’s especially true of high-precision gear like oscilloscopes from the time before ASICs and ADCs, which had to accomplish so much with discrete components and a lot of engineering ingenuity.

Unfortunately, though, those clever hacks that made everything work sometimes come back to bite you, as [Void Electronics] learned while bringing this classic Tektronix 466 scope back to life. A previous video revealed that the “Works fine, powers up” eBay listing for this scope wasn’t entirely accurate, as it was DOA. That ended up being a bad op-amp in the power supply, which was easily fixed. Once powered up, though, another, more insidious problem cropped up with the vertical attenuator, which failed with any setting divisible by two.

With this curious symptom in mind, [Void] got to work on the scope. Old analog Tek scopes like this use a bank of attenuator modules switched in and out of the signal path by a complex mechanical system of cams. It seemed like one of the modules, specifically the 4x attenuator, was the culprit. [Void] did the obvious first test and compared the module against the known good 4x module in the other channel of the dual-channel scope, but surprisingly, the module worked fine. That meant the problem had to be on the PCB that the module lives on. Close examination with the help of some magnification revealed the culprit — tin whiskers had formed, stretching out from a pad to chassis ground. The tiny metal threads were shorting the signal to ground whenever the 4x module was switched into the signal path. The solution? A quick flick with a sticky note to remove the whiskers!

This was a great fix and a fantastic lesson in looking past the obvious and being observant. It puts us in the mood for breaking out our old Tek scope and seeing what wonders — and challenges — it holds.

Quick and Very Dirty Repair Gets Smoked PLC Back in the Game

22 Noviembre 2024 at 06:00

When electronics release the Magic Smoke, more often than not it’s a fairly sedate event. Something overheats, the packaging gets hot enough to emit that characteristic and unmistakable odor, and wisps of smoke begin to waft up from the defunct component. Then again, sometimes the Magic Smoke is more like the Magic Plasma, as was the case in this absolutely smoked Omron programmable logic controller.

Normally, one tasked with repairing such a thing would just write the unit off and order a replacement. But [Defpom] needed to get the pump controlled by this PLC back online immediately, leading to the somewhat unorthodox repair in the video below. Whatever happened to this poor device happened rapidly and energetically, taking out two of the four relay-controlled outputs. [Defpom]’s initial inspection revealed that the screw terminals for one of the relays no longer existed, one relay enclosure was melted open, its neighbor was partially melted, and a large chunk of the PCB was missing. Cleaning up the damaged relays revealed what the “FR” in “FR4” stands for, as the fiberglass weave of the board was visible after the epoxy partly burned away before self-extinguishing.

With the damaged components removed and the dangerously conductive carbonized sections cut away, [Defpom] looked for ways to make a temporary repair. The PLC’s program was locked, making it impossible to reprogram it to use the unaffected outputs. Instead, he redirected the driver transistor for the missing relay two to the previously unused and still intact relay one, while adding an outboard DIN-mount relay to replace relay three. In theory, that should allow the system to work with its existing program and get the system back online.

Did it work? Sadly, we don’t know, as the video stops before we see the results. But we can’t see a reason for it not to work, at least temporarily while a new PLC is ordered. Of course, the other solution here could have been to replace the PLC with an Arduino, but this seems like the path of least resistance. Which, come to think of it, is probably what caused the damage in the first place.

Simple Stack of Ferrites Shows How Fluxgate Magnetometers Work

21 Noviembre 2024 at 06:00

Have you ever wondered how a magnetometer works? We sure have, which was why we were happy to stumble upon this article on simple homebrew fluxgate magnetometers.

As [Maurycy] explains, clues to how a fluxgate magnetometer works can be found right in the name. We all know what happens when a current is applied to a coil of wire wrapped around an iron or ferrite core — it makes an electromagnet. Wrap another coil around the same core, and you’ve got a simple transformer.

Now, power the first coil, called the drive coil, with alternating current and measure the induced current on the second, or sense coil. Unexpected differences between the current in the drive coil and the sense coil are due to any external magnetic field. The difference indicates the strength of the field. Genius!

For [Maurycy]’s homebrew version, binocular ferrite cores were stacked one on top of each other and strung together with a loop of magnet wire passing through the lined-up holes in the stack. That entire assembly formed the drive coil, which was wrapped with copper foil to thwart eddy currents. The sense coil was made by wrapping another length of magnet wire around the drive coil package; [Maurycy] found that this orthogonal of coils worked better than an antiparallel coil setup at reducing interference from the powerful drive coil field.

Driving the magnetometer required adding a MOSFET amp to give a function generator a little more oomph. [Maurycy] mentions that scope probes will attenuate the weak sense coil current, so we assume that the sense coil output goes right into the oscilloscope via coax. Calibrating the instrument was accomplished with a homebrew coil and some simple calculations.

This was a great demo of magnetometry methods and some of the intricacies of measuring weak fields with simple instruments. We’ve covered fluxgate magnetometer basics before and even talked about how they made pre-GPS car navigation possible.

Junk Box Build Helps Hams with SDR

20 Noviembre 2024 at 09:00

SDRs have been a game changer for radio hobbyists, but for ham radio applications, they often need a little help. That’s especially true of SDR dongles, which don’t have a lot of selectivity in the HF bands. But they’re so darn cheap and fun to play with, what’s a ham to do?

[VK3YE] has an answer, in the form of this homebrew software-defined radio (SDR) helper. It’s got a few features that make using a dongle like the RTL-SDR on the HF bands a little easier and a bit more pleasant. Construction is dead simple and based on what was in the junk bin and includes a potentiometer for attenuating stronger signals, a high-pass filter to tamp down stronger medium-wave broadcast stations, and a series-tuned LC circuit for each of the HF bands to provide some needed selectivity. Everything is wired together ugly-style in a metal enclosure, with a little jiggering needed to isolate the variable capacitor from ground.

The last two-thirds of the video below shows the helper in use on everything from the 11-meter (CB) band down to the AM bands. This would be a great addition to any ham’s SDR toolkit.

Hackaday Links: November 17, 2024

18 Noviembre 2024 at 00:00
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A couple of weeks back, we covered an interesting method for prototyping PCBs using a modified CNC mill to 3D print solder onto a blank FR4 substrate. The video showing this process generated a lot of interest and no fewer than 20 tips to the Hackaday tips line, which continued to come in dribs and drabs this week. In a world where low-cost, fast-turn PCB fabs exist, the amount of effort that went into this method makes little sense, and readers certainly made that known in the comments section. Given that the blokes who pulled this off are gearheads with no hobby electronics background, it kind of made their approach a little more understandable, but it still left a ton of practical questions about how they pulled it off. And now a new video from the aptly named Bad Obsession Motorsports attempts to explain what went on behind the scenes.

To be quite honest, although the amount of work they did to make these boards was impressive, especially the part where they got someone to create a custom roll of fluxless tin-silver solder, we have to admit to being a little let down by the explanation. The mechanical bits, where they temporarily modified the CNC mill with what amounts to a 3D printer extruder and hot end to melt and dispense the solder, wasn’t really the question we wanted answered. We were far more interested in the details of getting the solder traces to stick to the board as they were dispensed and how the board acted when components were soldered into the rivets used as vias. Sadly, those details were left unaddressed, so unless they decide to make yet another video, we suppose we’ll just have to learn to live with the mystery.

What do mushrooms have to do with data security? Until this week, we’d have thought the two were completely unrelated, but then we spotted this fantastic article on “Computers Are Bad” that spins the tale of Iron Mountain, which people in the USA might recognize as a large firm that offers all kinds of data security products, from document shredding to secure offsite storage and data backups. We always assumed the “Iron Mountain” thing was simply marketing, but the company did start in an abandoned iron mine in upstate New York, where during the early years of the Cold War, it was called “Iron Mountain Atomic Storage” and marketed document security to companies looking for business continuity in the face of atomic annihilation. As Cold War fears ebbed, the company gradually rebranded itself into the information management entity we know today. But what about the mushrooms? We won’t ruin the surprise, but suffice it to say that IT people aren’t the only ones that are fed shit and kept in the dark.

Do you like thick traces? We sure do, at least when it comes to high-current PCBs. We’ve seen a few boards with really impressive traces and even had a Hack Chat about the topic, so it was nice to see Mark Hughes’ article on design considerations for heavy copper boards. The conventional wisdom with high-current applications seems to be “the more copper, the better,” but Mark explains why that’s not always the case and how trace thickness and trace spacing both need to be considered for high-current applications. It’s pretty cool stuff that we hobbyists don’t usually have to deal with, but it’s good to see how it’s done.

We imagine that there aren’t too many people out there with fond memories of Visual Basic, but back when it first came out in the early 1990s, the idea that you could actually make a Windows PC do Windows things without having to learn anything more than what you already knew from high school computer class was pretty revolutionary. By all lights, it was an awful language, but it was enabling for many of us, so much so that some of us leveraged it into successful careers. Visual Basic 6 was pretty much the end of the line for the classic version of the language, before it got absorbed into the whole .NET thing. If you miss that 2008 feel, here’s a VB6 virtual machine to help you recapture the glory days.

And finally, in this week’s “Factory Tour” segment we have a look inside a Japanese aluminum factory. The video mostly features extrusion, a process we’ve written about before, as well as casting. All of it is fascinating stuff, but what really got us was the glow of the molten aluminum, which we’d never really seen before. We’re used to the incandescent glow of molten iron or even brass and copper, but molten aluminum has always just looked like — well, liquid metal. We assumed that was thanks to its relatively low melting point, but apparently, you really need to get aluminum ripping hot for casting processes. Enjoy.

Schooling ChatGPT on Antenna Theory Misconceptions

17 Noviembre 2024 at 18:00

We’re not very far into the AI revolution at this point, but we’re far enough to know not to trust AI implicitly. If you accept what ChatGPT or any of the other AI chatbots have to say at face value, you might just embarrass yourself. Or worse, you might make a mistake designing your next antenna.

We’ll explain. [Gregg Messenger (VE6WO)] asked a seemingly simple question about antenna theory: Does an impedance mismatch between the antenna and a coaxial feedline result in common-mode current on the coax shield? It’s an important practical matter, as any ham who has had the painful experience of “RF in the shack” can tell you. They also will likely tell you that common-mode current on the shield is caused by an unbalanced antenna system, not an impedance mismatch. But when [Gregg] asked Google Gemini and ChatGPT that question, the answer came back that impedance mismatch can cause current flow on the shield. So who’s right?

In the first video below, [Gregg] built a simulated ham shack using a 100-MHz signal generator and a length of coaxial feedline. Using a toroidal ferrite core with a couple of turns of magnet wire and a capacitor as a current probe for his oscilloscope, he was unable to find a trace of the signal on the shield even if the feedline was unterminated, which produces the impedance mismatch that the chatbots thought would spell doom. To bring the point home, [Gregg] created another test setup in the second video, this time using a pair of telescoping whip antennas to stand in for a dipole antenna. With the coax connected directly to the dipole, which creates an unbalanced system, he measured a current on the feedline, which got worse when he further unbalanced the system by removing one of the legs. Adding a balun between the feedline and the antenna, which shifts the phase on each leg of the antenna 180° apart, cured the problem.

We found these demonstrations quite useful. It’s always good to see someone taking a chatbot to task over myths and common misperceptions. We look into baluns now and again. Or even ununs.

Classic LED Bubble Displays Ride Again

17 Noviembre 2024 at 09:00

Hewlett-Packard used to make some pretty cool LED displays, many of which appeared in their iconic pocket calculators back in the 1970s and 1980s. [Upir] tracked down some of these classic bubble displays and used them with a microcontroller. We love the results!

The displays featured here, the HPDL-1414, aren’t quite what would have been found in an HP-35, of course. These displays have 16 segments for reasonably legible approximations of most of the ASCII character set. Also, these aren’t just the displays; rather, a pair of the bubble-topped displays, each with four characters, is mounted to a module that provides a serial interface. [Upir] found these modules online, but despite the HP logo on the PCB silkscreen, it’s not really clear who made them. The documentation was a bit thin, to say the least, but with a little translation help from Google, he figured out the serial parameters and the character encoding. The video below shows him putting these modules through their paces.

Unusually for [upir], who has made a name for himself hacking displays to do things they weren’t designed to do, he stuck with the stock character set baked into this module. We think it would be fun to get one of these modules and hack the firmware to provide alternative character sets or even get a few of the naked displays and build a custom interface. Sounds like a fun rainy-day project.

This reminded us of another HP display project we saw a while back. Or, roll your own displays.

Homebrew pH Meter Uses Antimony Electrode

15 Noviembre 2024 at 12:00

Understanding the nature of pH has bedeviled beginning (and not-so-beginning) chemistry students for nearly as long as chemistry has had students. It all seems so arbitrary, being the base-10 log of the inverse of hydrogen ion concentration and with a measurement range of 0 to 14. Add to that the electrochemical reactions needed to measure pH electronically, and it’s enough to make your head spin.

Difficulties aside, [Markus Bindhammer] decided to tackle the topic and came up with this interesting digital pH meter as a result. Measuring pH electronically is all about the electrode, or rather a pair of electrodes, one of which is a reference electrode. The potential difference between the electrodes when dipped into the solution under test correlates to the pH of the solution. [Markus] created his electrode by drawing molten antimony into a length of borosilicate glass tubing containing a solid copper wire as a terminal. The reference electrode was made from another piece of glass tubing, also with a copper terminal but filled with a saturated solution of copper(II) sulfate and plugged with a wooden skewer soaked in potassium nitrate.

In theory, this electrode system should result in a linear correlation between the pH of the test solution and the potential difference between the electrodes, easily measured with a multimeter. [Marb]’s results were a little different, though, leading him to use a microcontroller to scale the electrode output and display the pH on an OLED.

The relaxing video below shows the build process and more detail on the electrochemistry involved. It might be worth getting your head around this, since liquid metal batteries based on antimony are becoming a thing.

Desert Island Acetylene from Seashells and Driftwood

15 Noviembre 2024 at 09:00

[MacGyver] would be proud of [Hyperspace Pirate]’s rough and ready method of producing acetylene gas from seashells and driftwood.

Acetylene, made by decomposing calcium carbide with water, is a vitally important industrial gas. Not only as a precursor in many chemical processes, but also as the fuel for the famous “blue wrench,” a tool without which auto mechanics working in the Rust Belt would be reduced to tears. To avoid this, [Hyperspace Pirate] started by beachcombing for the raw materials: shells to make calcium oxide and wood to make charcoal. Charcoal is pretty easy; you just cook chunks of wood in a reducing environment to drive off everything but the carbon. Making calcium oxide from the calcium carbonate in the shells isn’t much harder, with ground seashells heated in a propane-fired furnace to release carbon dioxide.

With the raw ingredients in hand, things get a little tricky. Making calcium carbide requires a lot of heat, far more than a simple propane burner can provide. [Hyperspace Pirate] decided to go with an electric arc furnace, to which end he cannibalized a 120 V to 240 V step-up converter for its toroidal transformer, which with a few extra windings provided the needed current to run an arc through carbon electrodes. This generated the needed heat, and then some, as the ceramic firebrick he was using to contain the inferno melted. After rewinding the melted secondary windings on his makeshift transformer and switching to a stainless steel crucible, he was able to make enough calcium carbide to generate an impressive amount of acetylene. The video below documents the process and the sooty results, as well as details a little of the excitement that metal acetylides offer.

For more about acetylene and its many uses, [This Old Tony] has you covered.

Retro Calculator Build Proves the Space Age Isn’t What It Used to Be

15 Noviembre 2024 at 06:00

The common wisdom these days is that even if we wanted to get back to the Moon the way we did in the 1960s, we’d never be able to do it. Most of the blame for that usually falls on the loss of institutional knowledge thanks to skilled minds and hands that have been stilled by the passage of time, but the real kicker would be finding replacements for all the parts that we used back then that just aren’t made anymore. A similar problem exists for those seeking to recreate the circuits that graced the pages of the many magazines that catered to electronics hobbyists back in the day.

Take this “Space Age Decimal Computer” reproduction that [Bob Alexander] undertook. Smitten with the circuit after seeing our story about a 1966 article detailing its construction, he decided to roll one of his own. That proved to be far harder than he thought it would be. The original circuit, really little more than an adding machine using a rotary telephone dial as an input device, used neon lamp ring buffers for counting, The trouble is, while NE-2 neon lamps are still made, they aren’t made very precisely. That makes it difficult to build a working ring buffer, which relies on precise on and off voltages. That was even a problem back then; the author suggested buying 100 lamps and carefully characterizing them after aging them in to get the 60 lamps needed.

In the end, [Bob] settled for modifying the circuit while making the build look as close as possible to the original. He managed to track down the exact model of enclosure used in the original. The front panel is populated with a rotary dial just like the original, and the same neon lamps are used too, but as indicators rather than in ring buffers. Behind the scenes, [Bob] relied on 7400-series counters and decoders to make it all work — kudos for sticking with 1970s tech and not taking the easy way out with an Arduino.

The video below goes into more detail on the build and the somewhat kludgy operation of the machine, with a few excellent [Tom Lehrer] references and a nice Cybertruck dunk to boot.

Bluetooth Dongle Gives Up Its Secrets with Quick Snooping Hack

14 Noviembre 2024 at 21:00

There’s a lot going on in our wireless world, and the number of packets whizzing back and forth between our devices is staggering. All this information can be a rich vein to mine for IoT hackers, but how do you zero in on the information that matters? That depends, of course, but if your application involves Bluetooth, you might be able to snoop in on the conversation relatively easily.

By way of explanation, we turn to [Mark Hughes] and his Boondock Echo, a device we’ve featured in these pages before. [Mark] needed to know how long the Echo would operate when powered by a battery bank, as well as specifics about the power draw over time. He had one of those Fnirsi USB power meter dongles, the kind that talks to a smartphone app over Bluetooth. To tap into the conversation, he enabled Host Control Interface logging on his phone and let the dongle and the app talk for a bit. The captured log file was then filtered through WireShark, leaving behind a list of all the Bluetooth packets to and from the dongle’s address.

That’s when the fun began. Using a little wetware pattern recognition, [Mark] was able to figure out the basic structure of each frame. Knowing the voltage range of USB power delivery helped him find the bytes representing voltage and current, which allowed him to throw together a Python program to talk to the dongle in real-time and get the critical numbers.

It’s not likely that all BLE-connected devices will be as amenable to reverse engineering as this dongle was, but this is still a great technique to keep in mind. We’ve got a couple of applications for this in mind already, in fact.

Landscape Motif Makes This E-Ink Weather Display Easy to Understand

13 Noviembre 2024 at 21:00

True weather geeks will disagree, but there might be a better way to know how to dress for the day than divining what the weather will likely be from the current readings for temperature, pressure, humidity, and wind. Sure, the data will give you a good idea of where the weather is heading, but perhaps a quick visual summary such as the one offered by this pictorial landscape weather display is a better way to get out the door in the morning.

While many consumer weather stations incorporate some kind of graphical forecast for quick reference, [lds133] took a slightly different approach to forecasting. A cartoon landscape represents the day ahead, with various elements representing the coming weather scrolling across the display as time progresses. Trees are used to indicate wind direction and speed, with palm trees indicating south wind and pine trees winds from the north, and the taller the trees, the stronger the wind. The forest floor rises and falls with the expected temperature, the sun and moon appear at the proper time to indicate sunrise and sunset, and cloud icons are added when needed to show the degree of cloud cover. And because into each life a little rain must fall, animations show when you can expect rain or snow.

As for the electronics, if you think this would be a perfect application for an E-ink module, [lds133] agrees. The 296×128 pixel Waveshare display is the perfect aspect ratio for the job and provides nice, crisp icons. The display is updated every 15 minutes from the OpenWeather API by a Python program running on an ESP32 behind the scenes.

We’ve seen similar graphical forecast displays before, but we get it if that’s not your thing. Perhaps a more data-driven weather forecast will suit you better?

Hackaday Links: November 11, 2024

11 Noviembre 2024 at 00:00
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Fair warning, while the first item this week has no obvious connection to hacking, when 43 Rhesus monkeys escape from a lab, it’s just something that needs to be discussed. The tiny primates broke free from Alpha Genesis, a primate research facility in South Carolina. The monkey jailbreak seems to have occurred sometime on Wednesday, shortly after which the sheriff of Beaufort County was notified to be on the lookout for the tribe. Luckily, none of the animals has been used in any kind of infectious disease research, so this likely won’t be the origin story for anything apocalyptic. At least some of the animals were quickly located, doing their monkey thing in the woods and getting to swing from real trees for probably the first time in their lives. Alpha Genesis employees are trying to lure the monkeys back to captivity with food, but we suspect they’re too smart for that. They’ll probably come back on their own recognizance or when they get bored and realize that the real world isn’t all they thought it would be. When it’s all done we’d love to hear details about the breakout; was it something the monkeys got together and planned, or did one of the humans mess up?

With apologies in advance for the pun, there’s been a lot of buzz lately about tech billionaires falling over themselves to be the first to add “nuclear power mogul” to their CVs with reactor-powered AI data centers. In the early lead was Meta’s Mark Zuckerberg, but it looks like he might have reached an unexpected hurdle in the form of a rare species of bee in residence near the site where he was planning to build the data center. The original article is aggressively paywalled and we haven’t been able to find out exactly what species of bee bested Zuck or what the specific concerns are, although we suspect that it’s disruption of habitat due to construction activities for the data center itself rather than anything related to the nuclear power aspect, since the deal was with an operator of an existing power plant. But fear not — Microsoft, Google, and Amazon are all waiting in the wings with their own nuclear ambitions, so carbon-free AI searches thanks to controlled nuclear fusion will surely soon be a thing.

Although the bees may have thwarted Zuck, not so the Seven Seas, as news leaks indicate that Meta is in the process of building a globe-spanning underseas fiber optic cable. The cable is said to go from coast to coast in the USA the long way, starting in South Carolina across the Atlantic to a landing in Portugal, down the coast of Africa and around the Cape, up to India before heading through to Australia and back across the Pacific to California. The cable is said to carry 16 pairs of fibers and could provide Meta with 320 Tbps of data capacity. That’s a lot of memes.

While you’ve probably never heard of Elwood Edwards, who passed away this week at the age of 74, you’ve certainly heard his voice. Mr. Edwards was the announcer who recorded the famous “You’ve got mail!” email alert for AOL, along with other audio blurbs for the once-ubiquitous ISP. He worked in broadcasting, both AM radio and television, and voiced commercials and announcements before being recommended for the email gig by his wife, who worked at the company that would eventually become AOL, Quantum Computer Services. He got $200 for the session, which he recorded on a cassette tape in his living room, and which would be heard 35 million times a day at AOL’s peak. Not too shabby.

And finally, as proof that we’re living in the weirdest possible timeline comes the story of The Baguette Bandits. It seems that a hacker group — the other kind — broke into French company Schneider Electric and stole 40 GB of data, issuing a $125,000 ransom demand payable in baguettes. The hackers apparently penetrated Schneider via the company’s Jira system and claimed to have specific data on internal projects and issues along with 400,000 lines of user data, which they threatened to release unless they got the baked goods. They did stipulate that they’d halve the ransom amount if Schneider would publically acknowledge the breach. We’re not sure if they want half the number of baguettes or if they want the same number of loaves all cut in half, but either way, it’s a lot of bread. More puns are possible, but we think we’ll leave them all on the table. Seems the yeast we can do.

Clever Circuit Makes Exercise Slightly Less Boring

7 Noviembre 2024 at 00:00

We say this with the greatest respect, but [Joel] — your exercise routine is horrible! Kudos for getting up and doing something, but 108 trips up and down the stairs? That sounds like torture, not exercise. Even [Joel] admits that it’s so boring that he loses count, and while we’d bet that he isn’t likely to restart the routine when that happens, it’s still annoying enough that he built this clever little lap counter to automate the task.

We kid, of course; any exercise is better than no exercise, and the stairs offer few excuses for skipping the daily workout. To bust the boredom problem, [Joel] toyed with a couple of ideas for toting up his laps before landing on a beam-break optical system with sensors at the top and the bottom of the stairs. Worried about the potential for false triggering by swinging arms and legs, he searched for ideas for bounceless switch circuits in the old “Engineer’s Notebook” by [Forrest Mims] and found a circuit close enough to modify for his needs. Each sensor setup has a high-output red LED and a phototransistor on one side of the stairwell, and a retroreflector on the opposite wall. Breaking the beam switches off the LED on that sensor and switches the other one on, to save on battery power.

The sensor’s flips and flops are counted and displayed on a three-digit seven-segment LED; [Joel] offers no detail on the counter itself, but with [Mims] as his muse, we suspect it’s something like the three-digit BCD counter circuit a few pages on from the bounceless switch circuit. The lap counter is shown in action in the brief video below.

Zinc Creep and Electroplasticity: Why Arecibo Collapsed

6 Noviembre 2024 at 03:00

It’s been nearly four years since the Arecibo Telescope collapsed, an event the world got to witness in unprecedented detail thanks to strategically positioned drones. They captured breathtaking video of one of the support cables pulling from its socket as well as the spectacularly destructive results of 900 tons of scientific instruments crashing into the 300-meter primary reflector. But exactly why did those cable sockets fail?

A new report aims to answer that question, and in the process raises some interesting questions of its own. The proximate causes of the collapse have been known for a while, including the most obvious and visible one, the failure of the zinc “spelter sockets” that were cast around the splayed ends of the wire ropes to hold them in place. The new report agrees with this conclusion, at least in part, implicating “zinc creep,” or the tendency for zinc to deform over time under load. Where it appears to differ, though, is with the quality of workmanship on the sockets, finding no issues with the way the individual wires in the failed support cable were manually splayed within the socket before the molten zinc was poured. The report also points out that the collapse probably started when Hurricane Maria swept over Puerto Rico 39 months before the collapse, after which zinc creep in the sockets seemed to accelerate.

But why did the sockets fail? As the report points out, spelter sockets are commonly used to anchor cables that support heavy loads under conditions similar to the tropical climate at Arecibo. After ruling out every other cause, the committee was left with the conclusion that Arecibo itself may have been to blame for the accelerated zinc creep, thanks to electrical currents induced in the cables and sockets when the telescope’s powerful transmitters were used. They call this “long-term, low-current electroplasticity.” Electroplastic effects have been observed since the 1950s, and while far from certain that’s what happened here, the thought is that skin-effect currents induced in the support cables flowed to ground through the zinc sockets, increasing the plasticity of the metal and accelerating the zinc creep that ultimately led to collapse.

Case closed? Hardly. The electroplasticity mechanism for the Arecibo collapse offered by this report is almost a “diagnosis of exclusion” situation. It makes sense, though; since no other spelter sockets have ever failed this way in a century of use, there’s a good chance that the root cause was specific to Arecibo, and since it was once the world’s most powerful radio transmitter, it seems like a red flag that bears further investigation.

A Lesson in RF Design Thanks to This Homebrew LNA

5 Noviembre 2024 at 00:00

If you’re planning on working satellites or doing any sort of RF work where the signal lives down in the dirt, you’re going to need a low-noise amplifier. That’s typically not a problem, as the market is littered with dozens of cheap options that can be delivered in a day or two — you just pay your money and get to work. But is there a case to be made for rolling your own LNA?

[Salil, aka Nuclearrambo] thinks so, and he did a nice job showing us how it’s done. The first step, as always, is to define your specs, which for [Salil] were pretty modest: a low noise figure, moderate gain, and good linearity. He also wanted a bandpass filter for the 2-meter amateur radio band and for weather satellite downlinks, and a bias-tee to power the LNA over the coax feedline. The blog post has a detailed discussion of the electrical design, plus some good tips on PCB design for RF applications. We also found the discussion on bias-tee design helpful, especially for anyone who has ever struggled with the idea that RF and DC can get along together on a single piece of coax. Part 2 concentrates on testing the LNA, mostly using hobbyist-grade test gear like the NanoVNA and tiny SA spectrum analyzer. [Salil]’s tests showed the LNA lived up to the design specs and more, making it more than ready to put to work with an RTL-SDR.

Was this more work than buying an LNA? Absolutely, and probably with the same results. But then again, what’s to learn by just getting a pre-built module in the mail?

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