TechyMagThings

Considering how important it is for everything from navigation to keeping clocks in sync, satellite navigation systems are surprisingly vulnerable to a variety of attacks, ranging from simple jamming to more sophisticated spoofing attacks. This may be changing, though, as Galileo, Europe’s GNSS, recently demonstrated its first cryptographically-secured position fix under spoofing conditions.

Most GNSS systems, including GPS, have no verification measures to keep an adversary from transmitting a false signal at a higher power and hijacking a receiver; since GNSS signals are extremely weak by the time they reach the ground, this presents no great difficulty to a moderately well-equipped attacker.

Galileo’s Signal Authentication System (SAS) aims to fix this. The Galileo ground station pre-selects signal spreading codes, which it then encrypts with a regularly-changing secret key and publishes. A receiver which anticipates needing a verified signal can then download these encrypted codes ahead of time and store them. Galileo satellites then transmit on the E6-C pilot signal, and the receiver records the signal. After transmitting a message block, it then transmits the decryption key on a separate signal, which the receiver uses to recover the spreading codes. The receiver then correlates these spreading codes with the recorded signal to find the satellite’s pseudorange.

It’s a rather complicated system, but it works: earlier this month in Andøya, Norway, the annual Jammertest GNSS testing event took place. For one week, a wide range of organizations tested the resilience of their GNSS systems against various attacks, including jamming, delayed retransmission, and spoofing. Using five Galileo satellites, the European Space Agency was able to obtain a stable lock on their receiver even during spoofing.

In principle, this method could be extended to other GNSS systems. There’s certainly motivation to do so; very large-scale attacks have been demonstrated recently.

As useful as steel and iron are to the modern world, their tendency to rust is a major downside. There’s a spectrum of ways to prevent it, from quickly slapping on a coat of paint on the easy side to alloying, chromizing, or physical vapor deposition at the extremely difficult or industrial-only end. For a middle ground accessible to the home shop, galvanizing is a go-to method of rust prevention that deposits a layer of zinc onto the metal instead, but even this generally involves the use of strong acids. This method, though, makes galvanizing accessible without any acids. (Spoiler alert: substitute strong bases.)

Although the acids are omitted, the solution is caustic, so similar safety measures are still advised. The first step in the process is to dissolve sodium hydroxide into a container of distilled water. Metallic zinc can then be dissolved in the solution, with a bit of sugar and liquid soap to improve the finished quality of the coating. An electric current is applied to the solution, using a graphite plate at the anode and the part to be electroplated as the cathode. After some time, the part will be uniformly coated in a layer of zinc, which can then be brightened in a solution of only-mildly-acidic citric acid if needed.

One of the benefits of using a strong base to galvanize a metal part, beyond the preference of avoiding strong acids, is that this process can be better at plating parts that are non-uniform in shape, so things with deep crevices or other odd shapes that might coat unevenly in acid. If there’s a preference for electroplating with acid, there are some ways of producing one’s own using various methods.

The introduction of the ATmega32U4 microcontroller, with its integrated USB controller, made a lot of hardware tasks much simpler than they were before. One of the arenas it revolutionized was custom keyboards, making it much easier to build not only standard mechanical keyboards, but keyboards of all kinds of shapes and layouts and custom macro keyboards as well. This trend has continued on for the better part of the past decade with other microcontrollers beyond the 32U4 now available as well, but this modular macro keypad takes it to a new level by keeping that simplicity but also keeping costs down.

The suutari20, as it is called by its creator [Squalius] is able to achieve these aims by using 3.5 mm jacks commonly found in audio equipment. Each jack can support up to three keys, with the hub ultimately able to support 18 different keys. Those can include analog devices as well, such as volume knobs or jog controllers. The macro pad is powered by an RP2040 microcontroller from a Raspberry Pi Pico and uses QMK firmware, so those already familiar with custom keyboard programming will have no problem getting started.

From there, all that’s needed is a case, in this example a 3D printed one, and the commodity audio hardware to plug everything in to. It enables whatever functions can be thought of in a macro pad, and although the design focuses on simplicity and cost, this macro pad takes the concept to the extreme with modular keys that each have their own microcontroller built-in.

Everybody loves the Cheap Yellow Display (CYD) ESP32 dev boards, so why not treat yours to a little PDA? That’s right: turn it into a Portable Digital Assistant and relive the glory days of Palm with this project from [sau412].

For those readers who are too young to remember, a PDA was basically a phoneless and cameraless smart-phone, and devices running Palm Corporation’s Palm OS ruled the roost for most of the 90s and early 2000s. [sau412] hasn’t written an emulator or port of Palm OS; rather he’s created his own firmware for the ESP32-based CYD that is inspired by the PDAs of yore, and has many features you’d have expected back in the day. That includes a Gopher browser, to let you check out the undying alternative to the World Wide Web. There isn’t a general-purpose web browser, but there are RSS and Wikipedia readers, and what else do you need? At least you won’t end up doomscrolling.

There are also a passel of games and a BASIC interpreter, and the usual practical things like a calendar, calculator and contact list. Everything from ebook readers to translators, all of it by [sau421]. If you’ve got a CYD kicking around, you could do worse than give it a little PDA. Using the web-based flasher, we had it up and running in five minutes or so, but without an SD card we couldn’t test all the apps.

This is hardly the first ESP32 PDA  that we’ve featured, but leaning into the CYD means it’s the simplest project to replicate.  If you’re jonesing for the original Palm OS experience on more modern hardware, Pumpkin OS can get you going on x86 or ARM.

PCB circuits are cool, but you know what is cooler? Terminator circuits that’s what! And what if the same material that makes Terminator circuits could also be used for smart heat sinks, flexible circuits, and self-healing material properties? Well, that is exactly what the lab at Virginia Tech’s VT MADE Lab has created, presented by Joel from [3DPrintingNerd].

So what does a Terminator circuit actually entail? Well, just like in Terminator 2, the circuits are made of liquid metal. Specifically, small drops of liquid metal alloy made of gallium and indium. These drops are contained within a matrix of PDMS polymer, which contains the magical liquid for conductivity, thermal and electrical . This makes a flexible and stretchy composite which can even self-repair when punctured or cut by bridging the

broken circuit with the liquid alloy. Having a polymer matrix allows this self-repairing property but also makes the material insulating by default, only allowing current to flow after selectively “popping” the matrix bubbles.

To create something with the composite material, you’ll find it similar to many other resin-based materials. You can pour, mold, and even 3d print a custom geometry. A short bake later and you get a solidified model made for whatever custom flexible circuitry you have in mind.

While this process requires chemicals, polymerization reactions, and a taste for liquid alloys, that shouldn’t stop you from trying out flexible electronics. For a more hands on method to flexible electronics check out this glove with circuits running throughout!

Recently French and international researchers took a look at the state of the thousands of barrels of radioactive waste that were dumped into the Atlantic Ocean between 1950 and 1990, trying to ascertain the state of this waste and its effect on the ecosystem.

Although a lot of fuss is made of the spent uranium fuel and high-level waste produced by light water reactors and fuel reprocessing facilities, the overwhelming majority of nuclear waste is low- and intermediate-level waste (LLW and ILW) churned out by hospitals, laboratories and various industries.

Due to the sheer volume of this waste over the decades creative ways have been sought to dispose of it, which include burying in landfills and incinerating.

For a while tossing such waste into the ocean was also deemed to be an excellent destination for LLW and ILW, with the latter especially encapsulated in bitumen or cement. This was the poured into the barrels that many people have come to associate with nuclear waste in general. Since the approximately 200,000 tons of such barrels and similar were tossed into the Atlantic Ocean decades ago the question was where they ended up and their state.

The Radiocean mission site lists the objectives, including the mapping of the sites and identifying the elements of the ecosystems in addition to any radioisotope levels and their effect on said ecosystems. As it turns out, although the barrels have definitely degraded and their contents are slowly collapsing, the local ecosystems seem to have adapted well, treating the dump sites more as convenient shelters rather than a hazard. Some more photos can be found on the Bluesky account of [Javier Escartin].

None of this should come as a surprise if you are aware of just how much radioactive material is already dissolved naturally in the oceans, with much more uranium present in seawater than can be mined on-shore. Although the introduction of isotopes that are not part of the normal thorium and uranium decay chains into the ocean is of course undesirable, it’s good to know that this rather haphazard treatment of LLW and ILW has apparently just resulted in some Atlantic Ocean floor critters ending up with an interesting reef.

Recently [The Parallel Port] was asked to take a look at repairing the PoE++ feature on a Ubiquiti switch that otherwise worked fine. This is a pretty nice 24-port rackmounted switch with 2.5 Gbit-capable RJ-45 ports and two 10 Gbit SFP+ ports, so by itself it’s pretty useful, but having the 400 Watt PoE feature just go AWOL still stings, especially if you bought it new for $800.

With power applied the switch starts up as normal, including its 1.3″ touch screen that provides direct port information as well as a fancy screensaver cum QR code for the AR feature.

After logging into the switch’s BusyBox console it showed that all ports reported bad for the PwrGood status, and there were PoE power status request errors in the log, but this could be just the consequence of something else. Using a PoE splitter it was confirmed that the PoE functionality was indeed dead.

After disassembly and some testing with a multimeter and thermal camera, a short and related hot spot on the PCB that the PoE power board connects to was identified, with the short persisting after removing this PCB from the switch. Since the switch had suffered a bit of an electrical event the TVS diode was checked, but it turned out to be fine.

Next to it, marked as fuses, were protective thyristor surge protection devices (Trisil), functioning as a crowbar device. These aren’t supposed to be shorted to ground until a surge event occurs, but these were indeed both shorted when measured directly. Clearly they had taken the brunt of the electrical event and sacrificed themselves in the process.

One replacement later of these devices the switch now happily reports a good PoE status and even was able to power a DC fan via the PoE splitter. Even if it wasn’t a particularly hard fix, this is definitely one of those cases where knowing how the protective circuit works can save a lot of time in diagnosing and fixing a fault.