2026-02-17 23:00:59
Imagine a line of affordable toys controlled by the player’s brainwaves. By interpreting biosignals picked up by the dry electroencephalogram (EEG) electrodes in an included headset, the game could infer the wearer’s level of concentration, through which it would be possible to move physical objects or interact with virtual characters. You might naturally assume such devices would be on the cutting-edge of modern technology, perhaps even a spin-off from one of the startups currently investigating brain-computer interfaces (BCIs).
But the toys in question weren’t the talk of 2025’s Consumer Electronics Show, nor 2024, or even 2020. In actual fact, the earliest model is now nearly as old as the original iPhone. Such is the fascinating story of a line of high-tech toys based on the neural sensor technology developed by a company called Neurosky, the first of which was released all the way back in 2009.
Yet despite considerable interest leading up to their release — fueled at least in part by the fact that one of the models featured Star Wars branding and gave players the illusion of Force powers — the devices failed to make any lasting impact, and have today largely fallen into obscurity. The last toy based on Neurosky’s technology was released in 2015, and disappeared from the market only a few years later.
I had all but forgotten about them myself, until I recently came across a complete Mattel Mindflex at a thrift store for $8.99. It seemed a perfect opportunity to not only examine the nearly 20 year old toy, but to take a look at the origins of the product, and find out what ultimately became of Neurosky’s EEG technology. Was the concept simply ahead of its time? In an era when most people still had flip phones, perhaps consumers simply weren’t ready for this type of BCI. Or was the real problem that the technology simply didn’t work as advertised?
NeuroSky was founded in 1999 to explore commercial applications for BCIs, and as such, they identified two key areas where they thought they could improve upon hardware that was already on the market: cost, and ease of use.
Cost is an easy enough metric to understand and optimize for in this context — if you’re trying to incorporate your technology into games and consumer gadgets, cheaper is better. To reduce costs, their hardware wasn’t as sensitive or as capable as what was available in the medical and research fields, but that wasn’t necessarily a problem for the sort of applications they had in mind.
Of course, it doesn’t matter how cheap you make the hardware if manufacturers can’t figure out how to integrate it into their products, or users can’t make any sense of the information. The average person certainly wouldn’t be able to make heads or tails of the raw data coming from electroencephalography or electromyography sensors, and the engineers looking to graft BCI features into their consumer products weren’t likely to do much better.
To address this, NeuroSky’s technology presented the user with simple 0 to 100 values for more easily conceptualized parameters like concentration and anxiety based on their alpha and beta brainwaves. This made integration into consumer devices far simpler, albeit at the expense of accuracy and flexibility. The user could easily see when values were going up and down, but whether or not those values actually corresponded with a given mental state was entirely up to the interpretation being done inside the hardware.
These values were easy to work with, and with some practice, NeuroSky claimed the user could manipulate them by simply focusing their thoughts. So in theory, a home automation system could watch one of these mental parameters and switch on the lights when the value hit a certain threshold. But the NeuroSky BCI could never actually sense what the user was thinking — at best, it could potentially determine how hard an individual was concentrating on a specific thought. Although in the end, even that was debatable.
After a few attempted partnerships that never went anywhere, NeuroSky finally got Mattel interested in 2009. The result was the Mindflex, which tasked the player with maneuvering a floating ball though different openings. The height of the ball, controlled by the speed of the blower motor in the base of the unit, was controlled by the output of the NeuroSky headset. Trying to get two actionable data points out of the hardware was asking a bit much, so moving the ball left and right must be done by hand with a knob.
But while the Mindflex was first, the better known application for NeuroSky’s hardware in the entertainment space is certainly the Star Wars Jedi Force Trainer released by Uncle Milton a few months later. Fundimentally, the game worked the same way as the Mindflex, with the user again tasked with controlling the speed of a blower motor that would raise and lower a ball.
But this time, the obstacles were gone, as was the need for a physical control. It was a simpler game in all respects. Even the ball was constrained in a clear plastic tube, rather than being held in place by the Coandă effect as in the Mindflex. In theory, this made for a less distracting experience, allowing the user to more fully focus on trying to control the height of the ball with their mental state.
But the real hook, of course, was Star Wars. Uncle Milton cleverly wrapped the whole experience around the lore from the films, putting the player in the role of a young Jedi Padawan that’s using the Force Trainer to develop their telekinetic abilities. As the player attempted to accurately control the movement of the ball, voice clips of Yoda would play to encourage them to concentrate harder and focus their minds on the task at hand. Even the ball itself was modeled after the floating “Training Remote” that Luke uses to practice his lightsaber skills in the original film.
The Force Trainer enjoyed enough commercial success that Uncle Milton produced the Force Trainer II in 2015. This version used a newer NeuroSky headset which featured Bluetooth capability, and paired it with an application running on a user-supplied Android or Apple tablet. The tablet was inserted into a base unit which was able to display “holograms” using the classic Pepper’s Ghost illusion. Rather than simply moving a ball up and down, the young Jedi in training would have to focus their thoughts to virtually lift a 3D model of an X-Wing out of the muck or knock over groups of battle droids.
Unfortunately, Force Trainer II didn’t end up being as successful as its predecessor, and was discontinued a few years later. Even though the core technology was the same as in 2009, the reviews I can still find online for this version of the game are scathing. It seems like most of the technical problems came from the fact that users had to connect the headset to their own device, which introduced all manner of compatibility issues. Others claimed that the game doesn’t actually read the player’s mental state at all, and that the challenges can be beaten even if you don’t wear the headset.
The headsets for both the Mindflex and the original Force Trainer use the same core hardware, and NeuroSky even released their own “developer version” of the headset not long after the games hit the market which could connect to the computer and offered a free SDK.
Over the years, there have been hacks to use the cheaper Mindflex and Force Trainer headsets in place of NeuroSky’s developer version, some of which have graced these very pages. But somehow we missed what seems to be the best source of information: How to Hack Toy EEGs. This page not only features a teardown of the Mindflex headset, but shows how it can be interfaced with the Arduino so brainwave data can be read and processed on the computer.
I haven’t gone too far down this particular rabbit hole, but I did connect the headset up to my trusty Bus Pirate 5 and could indeed see it spewing out serial data. Paired with a modern wireless microcontroller, the Mindflex could still be an interesting device for BCI experimentation all these years later. Though if you can pick up the Bluetooth Force Trainer II headset for cheap on eBay, it sounds like it would save you the trouble of having to hack it yourself.
So the big question: does the Mindflex, and by extension NeuroSky’s 2009-era BCI technology, actually work?
Before writing this article, I spent the better part of an hour wearing the Mindflex headset and trying to control the LEDs on the front of the device that are supposed to indicate your focus level. I can confidently say that it’s doing something, but it’s hard to say what. I found that getting the focus indicator to drop down to zero was relatively easy (story of my life) and nearly 100% repeatable, but getting it to go in the other direction was not as consistent. Sometimes I could make the top LEDs blink on and off several times in a row, but then seconds later I would lose it and struggle to light up even half of them.
Some critics have said that the NeuroSky is really just detecting muscle movement in the face — picking up not the wearer’s focus level so much as a twitch of the eye or a furrowed brow which makes it seem like the device is responding to mental effort. For what it’s worth, the manual specifically says to try and keep your face as still as possible, and I couldn’t seem to influence the focus indicator by blinking or making different facial expressions. Although if it actually was just detecting the movement of facial muscles, that would still be a neat trick that offered plenty of potential applications.
I also think that a lot of the bad experiences people have reported with the technology is probably rooted in their own unrealistic expectations. If you tell a child that a toy can read their mind and that they can move an object just by thinking about it, they’re going to take that literally. So when they put on the headset and the game doesn’t respond to their mental image of the ball moving or the LEDs lighting up, it’s only natural they would get frustrated.
So what about the claims that the Force Trainer II could be played without even wearing the headset? If I had to guess, I would say that if there’s any fakery going on, it’s in the game itself and not the actual NeuroSky hardware. Perhaps somebody was worried the experience would be too frustrating for kids, and goosed the numbers so the game could be beaten no matter what.
As for NeuroSky, they’re still making BCI headsets and offer a free SDK for them. You can buy their MindWave Mobile 2 on Amazon right now for $130, though the reviews aren’t exactly stellar. They continue to offer a single chip EEG sensor (datasheet, PDF) that you can integrate into your projects as well, the daughterboard for which looks remarkably similar to what’s in the Mindflex headset. Despite the shaky response to the devices that have hit the market so far, it seems that NeuroSky hasn’t given up on the dream of bringing affordable brain-computer interfaces to the masses.
2026-02-17 20:00:11
Apple AirTags have speakers in them, and the speaker is not entirely under the owner’s control. [Shahram] shows how the speaker of an AirTag can be disabled while keeping the device watertight. Because AirTags are not intended to be opened or tampered with, doing so boils down to making a hole in just the right place, as the video demonstrates.
How does putting a hole in the enclosure not compromise water resistance? By ensuring the hole is made in an area that is already “inside” the seal. In an AirTag, that seal is integrated into the battery compartment.
Behind the battery, the enclosure has a small area of thinner plastic that sits right above the PCB, and in particular, right above the soldered wire of the speaker. Since this area is “inside” the watertight seal, a hole can be made here without affecting water resistance.
Disabling the speaker consists of melting through that thin plastic with a soldering iron then desoldering the (tiny) wire and using some solder wick to clean up. It’s not the prettiest operation, but there are no components nor any particularly heat-sensitive bits in that spot. The modification has no effect on water resistance, and isn’t even visible unless the battery is removed.
In the video below, [Shahram] uses a second generation AirTag to demonstrate the mod, then shows that the AirTag still works normally while now being permanently silenced.
Why would one want to permanently silence an AirTag, putting it into so-called “stealth mode”? That’s a good question. If you’re not familiar, one of the circumstances under which AirTags emit sound is if it is separated from its owner and has been moving with someone else for some period of time. Intended as an anti-stalking feature, [Shahram] points out that this behavior can also be a nuisance or straight up undesirable. For example, one may be using the tag on a pet collar, to track one’s luggage, or on a potential theft target like a bike. Modern phones in any case alert their owners if a tag they do not own appears to be moving with them, also as an anti-stalking measure.
In [Shahram]’s case, he has hidden an AirTag on his bike. He figures that if his bike should be stolen, a beeping AirTag would announce its existence to the thief and they would in all likelihood simply locate and discard the tracker. But if the tag is silent, the thief — still notified by their phone that a tracker is with them but unable to locate it on the bike — would be more likely to discard the bike instead, allowing it to be safely recovered.
Regardless, the process shows how a careful understanding of a device’s internals can allow for modifications that don’t require opening the whole thing, and the process is a bit reminiscent of drilling into a Stadia controller to permanently disable the mic.
2026-02-17 17:00:25
Although off-the-shelf breadboards are plentiful and cheap, they almost always seem to use the same basic design. Although you can clumsily reassemble most of them by removing the voltage rail section and merging a few boards together, wouldn’t it be nice if you had a breadboard that you could stick e.g. one of those wide ESP32 development boards onto and still have plenty of holes to poke wires and component leads into? Cue [Ludwin]’s 3D printable breadboard design that adds a big hole where otherwise wasted contact holes would be.
The related Instructables article provides a visual overview of the rationale and the assembly process. Obviously only the plastic shell of the breadboard is printed, after which the standard metal contacts are inserted. These contacts can be ‘borrowed’ from commercial boards, or you can buy the contacts separately.
For the design files there is a GitHub repository, with breadboard designs that target the ESP32, Raspberry Pi Pico, and the Arduino Nano. An overview of the currently available board designs is found on the Hackaday.io project page, with the top image showing many of them. In addition to the single big space design there are also a few variations that seek to accommodate just about any component and usage, making it rather versatile.
2026-02-17 14:00:51
Because size matters when it comes to statistics, [Will Prowse] decided to not just bank on his handful of failed Battle Born LFP batteries when it came to documenting their failure modes. Instead he got a whole gaggle of them from a viewer who had experienced failures with their Battle Born LFP batteries for an autopsy, adding a total of 15 samples to the data set.
Interestingly, the symptoms of these dead batteries are all over the place, from a refusal to charge, some have the overheating terminal, some do not show any sign of life, others have charged cells but a non-responsive BMS, etc. As [Will] notes, it’s important to test batteries with a load and a charger to determine whether they are functional not just whether you can measure a charge.
Although some of the batteries still showed enough signs of life to be put aside for some load testing, the remaining ones were cut open to check their insides. This revealed the typical molten plastic at the terminals, but also a lot of very loose connections for the internal wiring. Another battery showed signs of corrosion inside, which could be due to either moisture intrusion or a cell having leaked its electrolyte.
While the full results will hopefully be released soon, the worrying thing about this latest batch of Battle Born LFP batteries is that they span quite a few years, with one being from 2018. Although it’s comforting that not every one of these batteries is necessarily going to catch on fire within its approximate 8-year lifespan, a lot seems to depend on exactly how you load and charge them, as [Will] is trying to figure out with the upcoming load testing. With the unit that he recently purchased for testing it turned out that lower currents actually made the melting problem much worse.
Between this video and the much awaited follow-up, [Will] actually got his hands on a troubled 300A-rated industrial Battle Born battery. During testing that one actually failed violently with a cell venting and the loose BMS rattling around in the case.
2026-02-17 11:00:10
With more and more sensors being crammed into the consumer devices that many of us wear every day, the question of where medical devices begin and end, and how they should be regulated become ever more pertinent. When a ‘watch’ no longer just shows the time, but can keep track of a dozen vital measurements, and the line between ‘earbud’ and ‘hearing aid’ is a rather fuzzy one, this necessitates that institutions like the US FDA update their medical device rules, as was done recently in its 2026 update.
This determines how exactly these devices are regulated, and in how far their data can be used for medical purposes. An important clarification made in the 2026 update is the distinction between ‘medical information’ and ‘signals/patterns’. Meaning that while a non-calibrated fitness tracker or smart watch does not provide medically valid information, it can be used to detect patterns and events that warrant a closer look, such as indications of arrhythmia or low blood oxygen saturation.
As detailed in the IEEE Spectrum article, these consumer devices are thus ‘general wellness’ devices, and should be marketed as such, without embellished claims. Least of all should they be sold as devices that can provide medical information.
Another major aspect with these general wellness devices is what happens to the data that they generate. While not medical information, it does provide health information about a person that e.g. a marketing company would kill for to obtain. This privacy issue is unresolved in the US market, while other countries prescribe strict requirements about such data handling.
Effectively, this leaves the designers of wearables relatively free to do whatever they want, as long as they do not claim that the medical data being produced from any sensors is medical information. How this data is being handled is strictly regulated in most markets, except for the US, which is quite worrying and something you should definitely be aware of.
As for other medical device purposes like hearing aids, the earbuds capable of this fortunately do not generally collect information. They do need to have local regulatory approval to enable the feature, however, even if you can bypass any geofencing with some creative hacking.
2026-02-17 08:00:41
[GreatScott] has recently been tinkering in the world of radio frequency emissions, going so far as to put their own designs in a proper test chamber to determine whether they meet contemporary standards for noise output. This led them to explore the concept of shielding, and how a bit of well-placed metal can make all the difference in this regard.
The video focuses on three common types of shielding—absorber sheets, shielding tapes, and shielding cabinets. A wide variety of electronic devices use one or more of these types of shielding. [GreatScott] shows off their basic effectiveness by putting various types of shielding in between a noise source and a near-field probe hooked up to a receiver. Just placing a bit of conductive material in between the two can cut down on noise significantly. Then, a software defined radio (SDR) was busted out for some more serious analysis. [GreatScott] shows how Faraday cages (or simple shielding cabinets] can be used to crush down spurious RF outputs to almost nothing, and how his noisy buck-boost designs can be quieted down with the use of the right absorber sheets that deal well with the problematic frequencies in question. The ultimate upshot of the tests is that higher frequencies respond best to conductive shielding that is well enclosed, while lower frequency noise benefits from more absorptive shielding materials with the right permeability for the job.
Shielding design can be a complex topic that you probably won’t master in a ten minute YouTube video, but this content is a great primer if you’re new to the topic. We’ve covered the topic before, too, particularly on how a bit of DIY shielding can really aid a cheap SDR’s performance. Video after the break.
