How many times do you have to forget your keys before you start hacking on the problem? For [Binh], the answer was 5 in the last month, and his hack was to make a gesture-based door unlocker. Which leads to the amusing image of [Binh] in a hallway throwing gang signs until he is let in.

The system itself is fairly simple in its execution: the existing deadbolt is actuated by a NEMA 17 stepper turning a 3D printed bevel gear. It runs 50 steps to lock or unlock, apparently, then the motor turns off, so it’s power-efficient and won’t burn down [Binh]’s room.

The software is equally simple; mediapipe is an ML library that can already do finger detection and be accessed via Python. Apparently gesture recognition is fairly unreliable, so [Binh] just has it counting the number of fingers flashed right now. In this case, it’s running on a Rasberry Pi 5 with a webcam for image input. The Pi connects via USB serial to an ESP32 that is connected to the stepper driver. [Binh] had another project ready to be taken apart that had the ESP32/stepper combo ready to go so this was the quickest option. As was mounting everything with double-sided tape, but that also plays into a design constraint: it’s not [Binh]’s door.

[Binh] is staying in a Hacker Hotel, and as you might imagine, there’s been more penetration testing on this than you might get elsewhere. It turns out it’s relatively straightforward to brute force (as you might expect, given it is only counting fingers), so [Binh] is planning on implementing some kind of 2FA. Perhaps a secret knock? Of course he could use his phone, but what’s the fun in that?

Whatever the second factor is, hopefully it’s something that cannot be forgotten in the room. If this project tickles your fancy, it’s open source on GitHub, and you can check it out in action and the build process in the video embedded below.

After offering thanks to [Binh] for the tip, the remaining words of this article will be spent requesting that you, the brilliant and learned hackaday audience, provide us with additional tips.

youtube.com/embed/yNJkpo-19DI?…

hackaday.com/2025/07/02/hack-s…

When it comes to text, how small is too small? The experts say a six point font is the minimum for readability, but as [James Bowman] shows us, you can get away with half of that.

The goal is to produce a 40-character display on a 24 mm x 24 mm LCD that has a resolution of 240 x 240 to show a serial terminal (or other data) on the “TermDriver2” USB-to-Serial adapter. With 24 lines, that’s a line per millimeter: very small text. Three points, to be precise, half what the experts say you need. Diving this up into 40 columns gives a character cell of six by nine pixels. Is it enough?

The raw font on the left, the subpixel rendering on the right. For once, it’s better if you don’t click to enlarge.
Not by itself, no. That’s where the hack comes in: sub-pixel rendering. After all, a “white” pixel on an LCD is actually three elements: a red, a green, and a blue subpixel, stacked side-by-each. Drive each of those subpixels independently and 240 pixels now becomes 720. That’s plenty for a 40 column terminal.

The article discusses how, in general terms, they pulled off the subpixel rendering and kept the font as legible as possible. We think it’s a good try, though the colored fringe around the characters can be uncomfortable to look at for some people — and then we can’t forget the physical size of the characters being 1 mm tall.

If this trick were being used on a larger display with a 240-wide resolution, we’d say “yes, very legible, good job!”– but at this size? We hope we can find our reading glasses. Still, it’s a neat trick to have in your back pocket for driving low-resolution LCDs.

It may not surprise you that aside from improving legibility, subpixel rendering is also used for pixel (er, sub-pixel) art.

The full set of glyphs in their subpixel-rendered glory.

hackaday.com/2025/07/02/subpix…

This week Jonathan chats with benny Vasquez about AlmaLinux! Why is AlmaLinux the choice for slightly older hardware? What is the deal with RISC-V? And how does EPEL fit in? Tune in to find out!

• linkedin.com/in/bennyvasquez/
• almalinux.org
• almalinux.org/blog/2025-04-24-…
• almalinux.org/blog/2025-06-26-…

youtube.com/embed/5G-wIcFLrnM?…

Did you know you can watch the live recording of the show right on our YouTube Channel? Have someone you’d like us to interview? Let us know, or contact the guest and have them contact us! Take a look at the schedule here.

play.libsyn.com/embed/episode/…

Direct Download in DRM-free MP3.

If you’d rather read along, here’s the transcript for this week’s episode.

Places to follow the FLOSS Weekly Podcast:

• Spotify
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Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)

Licensed under Creative Commons: By Attribution 4.0 License

hackaday.com/2025/07/02/floss-…

Le autorità spagnole hanno arrestato cinque persone sospettate di aver riciclato 540 milioni di dollari tramite investimenti illegali in criptovalute e di aver frodato più di 5.000 persone. L’operazione di polizia, denominata Borrelli, è stata condotta con il supporto e il coordinamento dell’Europol, nonché delle forze dell’ordine di Estonia, Francia e Stati Uniti.

Le truffe sugli investimenti in criptovalute vengono solitamente messe in atto tramite la truffa romantica (conosciuta anche come macellazione del maiale), divenuta popolare negli ultimi anni.

Lo schema prevede che i truffatori utilizzino l’ingegneria sociale e contattino persone (“maiali”) sui social media e sulle app di incontri. Col tempo, i criminali si guadagnano la fiducia delle vittime simulando un’amicizia o un interesse romantico, e a volte persino fingendosi amici nella vita reale delle vittime.

Una volta stabilito il “contatto”, a un certo punto i criminali propongono alla vittima di investire in criptovalute, reindirizzando la vittima a un sito web fasullo. Purtroppo, di solito è impossibile recuperare i fondi e ricevere il reddito dichiarato da tali “investimenti“. Di norma, dopo l'”investimento“, i fondi vengono movimentati attraverso numerosi conti, il che li rende estremamente difficili da tracciare.

L’indagine sulle attività del gruppo fraudolento è iniziata nel 2023. Da allora, gli esperti di reati finanziari di Europol hanno assistito le autorità spagnole coordinando le indagini e fornendo supporto operativo. Il giorno dell’operazione, un esperto di criptovalute è stato persino inviato in Spagna per assistere gli investigatori.

Mentre i metodi utilizzati dai criminali sono ancora oggetto di indagine, la polizia afferma di aver ormai compreso il modus operandi del gruppo, che ha spostato e nascosto i fondi rubati attraverso i suoi canali in Asia.

“Per svolgere le loro attività fraudolente, si ritiene che i leader del gruppo criminale si siano avvalsi di una rete di complici in tutto il mondo che raccoglievano fondi tramite prelievi di contanti, bonifici bancari e trasferimenti di criptovalute”, ha dichiarato Europol. “Gli investigatori sospettano che l’organizzazione criminale abbia creato una rete aziendale e bancaria con sede a Hong Kong che utilizzava gateway di pagamento e conti su vari exchange, creati a nome di persone diverse, per ricevere, conservare e trasferire fondi ottenuti tramite attività criminali”.

La dichiarazione di Europol sottolinea specificamente il ruolo dell’intelligenza artificiale nella diffusione delle frodi sugli investimenti, che stanno diventando sempre più sofisticate.

L'articolo Pig Butchering Scam: Arrestati 5 criminali in Spagna per una frode da 540 milioni di dollari proviene da il blog della sicurezza informatica.

When a fire breaks out in a high-rise building, conventional wisdom is that stairwells are the only way out. Lifts are verboten in such scenarios, while sheer height typically prevents any other viable route of egress from tall modern buildings. If the stairs are impassable, or you can’t reach them, you’re in dire peril.

In South Korea, though, there’s another option for escape. The answer involves strapping on a harness and descending down ropes hanging off the side of the building, just like in an action movie. It might sound terrifying, but these descending lifeline devices have become a common part of fire safety infrastructure across the country.

Going Down

The concept is elegantly simple—tall buildings like apartments and hotels feature compact rope escape devices that can be quickly deployed from windows or balconies. These allow people to control their descent down the exterior of a building in the event that there is no other route of escape. While fleeing a building down a rope is typically the preserve of fictional spies or trained climbers, these carefully engineered systems are designed for use by ordinary people in emergency situations.

youtube.com/embed/tboKzq3lx8M?…

The typical Korean descending lifeline comes as a kit with some simple components. It consists of a rope or cable, a friction-based descent control mechanism, and a harness system that can be donned quickly by sliding under the arms and tightening a strap. Deploying the device is relatively simple. The rope reel is attached to a large deployable hook that is firmly mounted to the building’s wall, using a screw-threaded coupling. The rope is then thrown out the window. At this point, the user merely needs to attach the harness and tighten it prior to leaving the building.
A typical lifeline descent kit, manufactured by Kfire. Credit: Kfire
When exiting the window, the user is instructed to face the wall on the way down, using their hands and/or feet to control the descent. Ultimately, though, the mechanical speed regulator ensures a safe pace of descent. The devices only allow the descent of one person at at time. However, each end of the rope has a harness. Thus, when one user has descended to ground level, the next person can grab the harness at the other end which has ascended to the window, and begin their descent. This can continue for as many people as needed.

Key to these devices is their focus on simplicity. The descent control mechanism uses a geared braking system that automatically limit the speed of descent to 1.5 meters/sec or less, preventing the user from descending too quickly even if they panic and release their grip. The lifelines are also sold in a range of different lengths to suit the heights of individual floors in a building. This is important to ensure that as the user hits the ground, the other end of the rope has carried the other harness back up to the floor for the next user. The longest variants typically sold are 45 meters in length, intended for buildings up to 15 stories tall. Limits of practicality mean that while these lifelines are useful for many buildings, they’re perhaps not applicable to taller skyscrapers where such escape would be more difficult.

The engineering challenge here isn’t just mechanical. Automatic rope descent systems are a well understood technology, as are hooks and brackets rated to carry human weight for climbing or otherwise. The real challenge comes down to human factors—in that these systems need to be something people can figure out how to use under conditions of extreme stress. The devices need to be intuitive enough that someone who has never used one before can figure it out while a fire rages behind them. It’s one thing to learn how to use a rope descent system by watching a video and trying the equipment at a calm training session. It’s another thing entirely to do so while a fire rages in the hotel hallway behind you.

While these lifeline systems are relatively simple, they’re still a lot more complicated to use than something like an airliner life jacket. Requiring an inexperienced end user to thread a fitting on a rope coupler without dropping it out the window in a panic situation is a tall ask. Still, the lifelines provide a useful additional escape option. It may not be the easiest way out of the building, or anybody’s first choice, but when there’s no other option, it’s good to have.

South Korea’s adoption of these systems reflects both the country’s high-rise-heavy urban landscape and a pragmatic approach to disaster preparedness. Many apartment buildings and hotels are now required to have these devices installed. The devices are typically mounted in weatherproof boxes near windows or on balconies, ready for deployment when traditional escape routes are compromised. In some cases, the rugged boxes the lifelines come in can even be used as a step-up to ease egress out of higher windows.

Perhaps most importantly, these systems represent a shift in traditional thinking about fire safety. In most jurisdictions, the idea of asking average people to belay down a building is considered untenable—too dangerous and too complicated. In South Korea, the lifelines are on hand, and put control back in the hands of building occupants. When every second counts and traditional escape routes have failed, having a lifeline system could mean the difference between life and death. It’s a sobering reminder that sometimes the best high-tech solution is one that lets people save themselves.