Cheap Hackable Smart Ring Gets A Command Line Client

March 4, 2025 by 18 Comments

Last year, we’ve featured a super cheap smart ring – BLE, accelerometer, heart sensor, and a battery, all in a tiny package that fits on your finger. Back when we covered it, we expected either reverse-engineering of stock firmware, or development of a custom firmware outright. Now, you might be overjoyed to learn that [Wesley Ellis] has written a Python client for the ring’s stock firmware.

Thanks to lack of any encryption whatsoever, you can simply collect the data from your ring, no pairing necessary, and [Wesley]’s work takes care of the tricky bits. So, if you want to start collecting data from this ring right now, integrate it into anything you want, such as your smart home or exoskeleton project, this client is enough. A few firmware secrets remain – for instance, the specific way that the ring keep track of day phases, or SPO2 intricacies. But there’s certainly enough here for you to get started with.

This program will work as long as your ring uses the QRing app – should be easy to check right in the store listing. Want to pick up the mantle and crack open the few remaining secrets? Everything is open-source, and there’s a notepad that follows the OG reverse-engineering journey, too. If you need a reminder on what this ring is cool for, here’s our original article on it.

CNC Router And Fiber Laser Bring The Best Of Both Worlds To PCB Prototyping

March 4, 2025 by 22 Comments

Jack of all trades, master of none, as the saying goes, and that’s especially true for PCB prototyping tools. Sure, it’s possible to use a CNC router to mill out a PCB, and ditto for a fiber laser. But neither tool is perfect; the router creates a lot of dust and the fiberglass eats a lot of tools, while a laser is great for burning away copper but takes a long time to burn through all the substrate. So, why not put both tools to work?

Of course, this assumes you’re lucky enough to have both tools available, as [Mikey Sklar] does. He doesn’t call out which specific CNC router he has, but any desktop machine should probably do since all it’s doing is drilling any needed through-holes and hogging out the outline of the board, leaving bridges to keep the blanks connected, of course.

Once the milling operations are done, [Mikey] switches to his xTool F1 20W fiber laser. The blanks are placed on the laser’s bed, the CNC-drilled through holes are used as fiducials to align everything, and the laser gets busy. For the smallish boards [Mikey] used to demonstrate his method, it only took 90 seconds to cut the traces. He also used the laser to cut a solder paste stencil from thin brass shim stock in only a few minutes. The brief video below shows the whole process and the excellent results.

In a world where professionally made PCBs are just a few mouse clicks (and a week’s shipping) away, rolling your own boards seems to make little sense. But for the truly impatient, adding the machines to quickly and easily make your own PCBs just might be worth the cost. One thing’s for sure, though — the more we see what the current generation of desktop fiber lasers can accomplish, the more we feel like skipping a couple of mortgage payments to afford one.

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It’s SSB, But Maybe Not Quite As You Know It

March 3, 2025 by 17 Comments

Single Sideband, or SSB, has been the predominant amateur radio voice mode for many decades now. It has bee traditionally generated by analogue means, generating a double sideband and filtering away the unwanted side, or generating 90 degree phase shifted quadrature signals and mixing them. More recent software-defined radios have taken this into the CPU, but here’s [Georg DG6RS] with another method. It uses SDR techniques and a combination of AM and FM to achieve polar modulation and generate SSB. He’s provided a fascinating in-depth technical explanation to help understand how it works.

The hardware is relatively straightforward; an SI5351 clock generator provides the reference for an ADF4351 PLL and VCO, which in turn feeds a PE4302 digital attenuator. It’s all driven from an STM32F103 microcontroller which handles the signal processing. Internally this means conventionally creating I and Q streams from the incoming audio, then an algorithm to generate the phase and amplitude for polar modulation. These are fed to the PLL and attenuator in turn for FM and AM modulation, and the result is SSB. It’s only suitable for narrow bandwidths, but it’s a novel and surprisingly simple deign.

We like being presented with new (to us at least) techniques, as it never pays to stand still. Meanwhile for more conventional designs, we’ve got you covered.

An excerpt from the website, showing the nRootTag block diagram and describing its structure

Hijacking AirTag Infrastructure To Track Arbitrary Devices

March 3, 2025 by 7 Comments

In case you weren’t aware, Apple devices around you are constantly scanning for AirTags. Now, imagine you’re carrying your laptop around – no WiFi connectivity, but BLE’s on as usual, and there’s a little bit of hostile code running at user privileges, say, a third-party app. Turns out, it’d be possible to make your laptop or phone pretend to be a lost AirTag – making it and you trackable whenever an iPhone is around.

The nroottag website isn’t big on details, but the paper ought to detail more; the hack does require a bit of GPU firepower, but nothing too out of the ordinary. The specific vulnerabilities making this possible have been patched in newer iOS and MacOS versions, but it’s still possible to pull off as long as an outdated-firmware Apple device is nearby!

Of course, local code execution is often considered a game over, but it’s pretty funny that you can do this while making use of the Apple AirTag infrastructure, relatively unprivileged, and, exfiltrate location data without any data connectivity whatsoever, all as long as an iPhone is nearby. You might also be able to exflitrate other data, for what it’s worth – here’s how you can use AirTag infrastructure to track new letter arrivals in your mailbox!

Make Your Own Air Knife And Air Amplifier

March 3, 2025 by 20 Comments

Want to make your own air knife to cut things with? Unfortunately that’s not what these devices are intended for, but [This Old Tony] will show you how to make your own, while explaining what they are generally intended for.  His version deviates from the commercial version which he got his hands on in that he makes a round version instead of the straight one, but the concept is the same.

In short, an air knife is a laminar pressurized airflow device that provides a very strong and narrow air pattern, using either compressed air or that from a blower. Generally air knives will use the Coandă effect to keep the laminar flow attached to the device for as long as possible to multiply the air pressure above that from the laminar flow from the air knife itself. These are commonly used for cleaning debris and dust off surfaces in e.g. production lines.

As [Tony] shows in the disassembly of a commercial device, they are quite basic, with just two aluminium plates and a thin shim that creates the narrow opening through which the air can escape. The keyword here is ‘thin shim’, as [Tony] discovers that even a paper shim is too thick already. Amusingly, although he makes a working round air knife this way, it turns out that these are generally called an air amplifier, such as those from Exair and are often used for cooling and ventilation, with some having an adjustable opening to adjust the resulting airflow.

Some may recognize this principle for those fancy ‘bladeless’ fans that companies like Dyson sell, as they use essentially the same principle, just with a fan providing the pressure rather than a compressor.

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Here’s A Spy Movie-Grade Access Card Sniffing Implant

March 3, 2025 by 17 Comments

Some of our devices look like they’re straight out of hacker movies. For instance, how about a small board you plant behind an RFID reader, collecting access card data and then replaying it when you next walk up the door? [Jakub Kramarz] brings us perhaps the best design on the DIY market, called The Tick – simple, flexible, cheap, tiny, and fully open-source.

Take off the reader, tap into the relevant wires and power pins (up to 25V input), and just leave the board there. It can do BLE or WiFi – over WiFi, you get a nice web UI showing you the data collected so far, and letting you send arbitrary data. It can do Wiegand like quite a few open-source projects, but it can also do arbitrary clock+data protocols, plus you can just wire it up quickly, and it will figure out the encoding.

We could imagine such a board inside a Cyberpunk DnD rulebook or used in Mr Robot as a plot point, except that this one is real and you can use it today for red teaming and security purposes. Not to say all applications would be NSA-catalog-adjacent pentesting – you could use such a bug to reverse-engineer your own garage door opener, for one.

Sensory Substitution Device Tingles Back Of Your Hand

March 3, 2025 by 3 Comments

A team from the University of Chicago brings us a new spin on sensory substitution, the “Seeing with the Hands” project, turning external environment input into sensations. Here specifically, the focus is on substituting vision into hand sensations, aimed at blind and vision disabled. The prototype is quite inspiration-worthy!

On the input side, we have a wrist-mounted camera, sprinkled with a healthy amount of image processing, of course. As for the output, no vibromotors or actuators are in use – instead, tactile receptors are stimulated by passing small amounts of current through your skin, triggering your touch receptors electrically. An 5×6 array of such “tactile” pixels is placed on the back of the hand and fingers. The examples provided show it to be a decent substitution.

This technique depends on the type of image processing being used, as well as the “resolution” of the pixels, but it’s a fun concept nevertheless, and the study preprint has some great stories to tell. This one’s far from the first sensory substitution devices we’ve covered, though, as quite a few of them were mechanical in nature – the less moving parts, the better, we reckon!