Mysterious Files PH

The great thing about the modern world is how connected we are. It’s also the worst thing about the modern world, to be honest. [Allan Binder] wanted to give his toddler the very best of that, and escape the worst, with a specially-designed telephone to call Grandma with– and not get scam calls in turn. We’re not going to say his build guide is so thorough a toddler could follow it, but it’s not too far off.

The device is very simple: a commercial ‘retro-style’ handset pairs with an ESP32-S3 over USB. Said ESP32, aside from acting as a USB host, runs a minimal Session Initiation Protocol (SIP) client, which connects via WiFi to a VoIP account the parent has set up. In this case, [Allan] is using Twilio, but there are other internet telephony providers one could use if a Twilio employee once ran over your dog or something.

There are no inbound calls in this setup, so little Timmy isn’t going  to be bothered needlessly about import fees on nonexistent packages or his car’s extended warranty. Dialing out is toddler-friendly, too– it’s as simple as mashing an arcade button linked to the ESP32’s GPIO. Each designated contact gets a button with its pre-programed contact, like the speed dial of yore. A really nice touch is the use of illuminated buttons tied to the time-zone of the designated contact: kiddo will learn quick that if the button isn’t lit, it’s not time for phone calls. The phone will actually say so, via a text-to-speech that also announces network errors and the like.

While cardboard box housing the prototype seems a bit flimsy to trust with any toddler we’ve met, but the concept here is very sound indeed. We’ve seen such kid-communication devices before, but this implementation, aside from being more current, has a lot to recommend it.

Thanks to [Allan Binder] for the tip!

The idea that magnetism doesn’t necessarily always have a dipolar configuration is not a new one, but it’s not an easy theory to find evidence for. Most recently a team of scientists at the University of Toronto used a new method involving vibrational energy in the form of phonons to find evidence for an octupolar magnetic order.

In the associated paper in Physical Review Letters (paywalled, arXiv version) by [Ruairidh Sutcliffe] et al. we can find more details on this method and what their findings may mean for various fields. Naturally, this is a quantum-level phenomenon that requires Raman spectroscopy to be detectable via said phonons.

The materials investigated here are also somewhat exotic, ranging from actinides like NpO₂ to transition metal oxides like Sr₂MgReO₆, while having on common strong spin-orbit coupling. Where the phonons come into play is that they can be used to indirectly measure crystal lattice distortions due to the pseudo-angular momentum assigned to the phonons. This generates pseudo-chiral phonons which then show up in the Raman spectroscopy.

Although finding evidence for octopolar magnetic order is interesting in itself, this way to measuring a crystal lattice’s structure makes for another fascinating research tool that can be used to study many similar phenomenon.

These quantum-level magnetic states could conceivably be used for anything from sensors to magnetic data storage, though any such research is unlikely to be commercialized any time soon.

What is hacking? Many, especially in the mainstream, view it through the lens of computer security. Others consider it synonymous with making or creating. Even for those of us immersed in the community, this can be a surprisingly difficult question to answer.

In his Hackaday Supercon 2026 keynote address, Bruce Potter will explore this idea by taking a step back and looking at what makes someone a hacker in the first place. Rather than viewing hacking as a singular act, he’ll make the case that it’s a mindset, a way of approaching problems that’s not strictly dependent on the tools used or even the desired outcome.

With a cybersecurity career that’s spanned three decades, Bruce has been involved with hacking at every level and in every form — from conducting DARPA research to founding The Shmoo Group and helping organize the legendary ShmooCon. Currently the Chief Product Officer at Trinity Cyber, Bruce has made creative problem solving his life’s work, and he’s eager to share what he’s learned with the Hackaday community. While most of us won’t get the opportunity to advise on national cybersecurity policy as he has, we can still apply the same techniques to our own personal and professional projects.

Those joining us this weekend in Pasadena will get to experience Bruce’s keynote, as well as more than 30 other fascinating presentations, with a group of individuals who are just as eager to understand the how and why of the world around them as you are. Making personal connections with like-minded folks is truly the highlight of Hackaday Supercon; badge hacking and tacos are just the fringe benefits.

In our totally unbiased opinion, we believe Hackaday Supercon is the ultimate hardware hacking conference, but you don’t have to take our word for it. A few tickets are still left if you want to see for yourself.

One of the easiest ways of improving security and privacy when using the Internet, and computers in general, is to use strong passwords unique to each site or service. A password manager makes this easy on your phone or computer, but what if you’re in a situation where you can’t install any software on the device you’re logging into? In that case, maybe it’s time to get out the Toothpaste.

The way this creation from [brisk4t] works is that an ESP32-S3 is programmed to act as a keyboard and mouse for any computer it’s plugged into. From there, it connects over an encrypted WEB-BLE connection to another device like a laptop or smartphone. This second device can send text to the ESP32 acting using an extension for Chromium-based browsers, and the ESP32 sends it over the USB connection as if it were nothing more than a standard keyboard. This is all done without having to install any apps or drivers on the target machine, since any machine in the last two or three decades can recognize a USB keyboard and mouse with no problem.

Not only does this allow for easy password input for awkward situations, this can also be used for BIOS where an app couldn’t be installed anyway, for air-gapped systems with no networking, or insecure systems the user doesn’t trust. If you don’t need quite as many bells and whistles, we’ve seen a similar technique pulled off with an ATtiny85.

Sometimes the naming of parts in electronics can contribute to confusion about what they are good for, with the topic of Zener diodes in the context of fast surges like those from electrostatic discharge (ESD) being a good example. In a recent video by [BTT Lab] this particular question regarding Zener suitability for suppressing ESD is addressed, as compared to transient-voltage-suppression (TVS) diodes.

The main argument against using Zener diodes for ESD and similar surge suppression is that they react too slowly, which obviously gives said surge time to cause some real damage. This is where a special form of avalanche effect-based diodes called TVS diodes are recommended, as their response time is in the picoseconds rather than nanoseconds or slower as for Zener diodes.

Although this is technically true, as also pointed out in the video, a Zener diode also uses the avalanche effect, with the diode starting off conducting in the reverse direction using the Zener effect before transitioning to the much faster avalanche effect. The transition point is hereby determined by how heavily the p-n junction is doped, making effectively all Zener diodes also avalanche diodes.

TVS diodes consequently are basically Zener diodes that are optimized for a very early transition to said avalanche effect. They are also generally larger than typical Zener diodes as they generate a lot of internal thermal energy while in reverse conducting mode, which has to be contained and shed without causing permanent damage.

The short version is thus that diodes marked as ‘TVS’ are the best choice for surge protection, while those marked as ‘Zener’ are best used for voltage clamping, reference voltages and all other typical Zener diode things.

It’s an exciting time to be a camera hacker, because we are at a moment when even cheap camera hardware is starting to have high resolution sensors, and the awesome camera phones of a few years ago are now in people’s junkboxes. Lens swapping has been a feature of the art for a while now, usually taking the form of a C-mount add-on. So with a bit of 3D printing and glue, you can now make something more interesting from an AliExpress purchase or that old phone. These cameras have all the resolution and sharpness that the sensor can deliver assuming that their software isn’t too awful, but there’s a persistent problem . The photographs invariably have a pinkish tint, as reported in a recent Hackaday-featured project, just to name one. The original lens doesn’t have this problem, so what’s up?

Of course, the more astute readers are immediately thinking about IR filters. I did too, when one of my on-and-off projects had the pink tint. It’s a Samsung Galaxy Tab 3, an ancient Android 5 phone with a rather useless and gimmicky stylus, and a rather nice camera sensor. I bought a replacement camera module for it on AliExpress so I’d have something to experiment with, removed its lens assembly, and had a phone with a bare sensor peeking from the back of it. A 3D printed adjustable lens mount assembly that I’ll eventually clean up and release so any phone can have the same modification followed.

Faced with the dreaded pink when I started taking pictures, I ineptly glued an IR filter to the back of it, and awaited my perfect shots. Sadly they never came, so rather than admit defeat, I’m hoping one of you lot can help. Are any Hackaday readers in the optics business and can tell me what’s up?

At the top of this page you’ll see a picture of some plush animals in a hackerspace. It was taken under LED room lighting with the modified Galaxy Tab 3 and a decent quality Fuji C-mount lens, not a cheap security camera item. It’s hand focused as best as I could make it, but that’s not the problem with this image. Immediately you can see the pink cast, in the same way as all those other people’s projects, stronger at the edges and mostly not there in the middle.

I have an IR filter in place, so the obvious question becomes, is it a poor quality filter that’s still letting IR through, or is the pink tint from another source? If it’s from another source, is it something in the lens? Does the stock lens have some special magic?

Given that this lens is designed to be used with 8mm film and vacuum-tube TV cameras, I know it doesn’t impart a pink cast on its own, there’s no red shift at the edges from dodgy optics. It’s even easy enough to fix in software via white balance, but that’s not the point. There’s something wrong with this camera, and even though the whole project has only cost me a few quid, I’d like to know what it is. Are you the Hackaday-reading optical specialist who can help me and all those other camera hackers? The comments await your wisdom.

Recently [DiodeGoneWild] got his paws on a purportedly IP44-rated outdoor solar light with PIR motion sensor that also contains an 18650 Li-ion cell. Since it’s being sold in Czechia in a supermarket by a Czech company you’d expect it to meet at least some quality standards, but once he got inside the device a true horror show unfolded.

The best guess here is that someone took an originally cheap NiMH cell-based solar light circuit and simply replaced said NiMH cell with an – unprotected – Li-ion 18650 cell, as there is absolutely no charging management or cell protection. This is important as while NiMH will throttle charging current by rejecting it as heat the more it is in a charged state, Li-ion is not as tolerant.

Even ignoring that the ‘IP44’ enclosure has more gaps and holes in it than the average slice of Swiss cheese, the 5.5 V-rated PV solar panel happily tried charging the Li-ion cell at around 6 V. This raises the potential that on a particularly sunny day with an already charged Li-ion cell sitting at 4.2+ V, it’ll effectively grenade this cell.

During an outdoors test the 18650 cell was charged to 4.8 V before the sun vanished behind the building, which probably isn’t an amazing sign if you are expecting for this light to keep working for more than a few weeks. Or not violently explode/catch on fire on the side of your house for that matter.

Of course, treating a NiMH cell better than in this particular circuit will extend its lifespan as well, but the failure mode of that battery chemistry tends to be a bit less aggressive. Hence why people keep getting away with dodgy circuit designs like this.