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Reshaping Eyeballs With Electricity, No Lasers Or Cutting Required

October 8, 2025 by 35 Comments

Glasses are perhaps the most non-invasive method of vision correction, followed by contact lenses. Each have their drawbacks though, and some seek more permanent solutions in the form of laser eye surgeries like LASIK, aiming to reshape their corneas for better visual clarity. However, these methods often involve cutting into the eye itself, and it hardly gets any more invasive than that.

A new surgical method could have benefits in this regard, allowing correction in a single procedure that requires no lasers and no surgical cutting of the eye itself. The idea is to use electricity to help reshape the eye back towards greater optical performance.

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Airbags, And How Mercedes-Benz Hacked Your Hearing

October 6, 2025 by 41 Comments

Airbags are an incredibly important piece of automotive safety gear. They’re also terrifying—given that they’re effectively small pyrotechnic devices that are aimed directly at your face and chest. Myths have pervaded that they “kill more people than they save,” in part due a hilarious episode of The Simpsons. Despite this, they’re credited with saving tens of thousands of lives over the years by cushioning fleshy human bodies from heavy impacts and harsh decelerations.

While an airbag is generally there to help you, it can also hurt you in regular operation. The immense sound pressure generated when an airbag fires is not exactly friendly to your ears. However, engineers at Mercedes-Benz have found a neat workaround to protect your hearing from the explosive report of these safety devices. It’s a nifty hack that takes advantage of an existing feature of the human body. Let’s explore how air bags work, why they’re so darn loud, and how that can be mitigated in the event of a crash.

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On 3D Scanners And Giving Kinects A New Purpose In Life

October 2, 2025 by 32 Comments

The concept of a 3D scanner can seem rather simple in theory: simply point a camera at the physical object you wish to scan in, rotate around the object to capture all angles and stitch it together into a 3D model along with textures created from the same photos. This photogrammetry application is definitely viable, but also limited in the sense that you’re relying on inferring three-dimensional parameters from a set of 2D images and rely on suitable lighting.

To get more detailed depth information from a scene you’d need to perform direct measurements, which can be done physically or through e.g. time-of-flight (ToF) measurements. Since contact-free ways of measurements tend to be often preferred, ToF makes a lot of sense, but comes with the disadvantage of measuring of only a single spot at a time. When the target is actively moving, you can fall back on photogrammetry or use an approach called structured-light (SL) scanning.

SL is what consumer electronics like the Microsoft Kinect popularized, using the combination of a visible and near-infrared (NIR) camera to record a pattern projected onto the subject, which is similar to how e.g. face-based login systems like Apple’s Face ID work. Considering how often Kinects have been used for generic purpose 3D scanners, this raises many questions regarding today’s crop of consumer 3D scanners, such as whether they’re all just basically Kinect-clones.

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A Cut Above: Surgery In Space, Now And In The Future

September 30, 2025 by 3 Comments

In case you hadn’t noticed, we live in a dangerous world. While our soft, fleshy selves are remarkably good at absorbing kinetic energy and healing the damage that results, there are very definite limits to what we humans can deal with, beyond which we’ll need some help. Car crashes, falls from height, or even penetrating trauma such as gunshot wounds — events such as these will often land you in a trauma center where, if things are desperate enough, you’ll be on the operating table within the so-called “Golden Hour” of maximum survivability, to patch the holes and plug the leaks.

While the Golden Hour may be less of a hard limit than the name implies, it remains true that the sooner someone with a major traumatic injury gets into surgery, the better their chances of survival. Here on planet Earth, most urban locations can support one or more Level 1 trauma centers, putting huge swathes of the population within that 60-minute goal. Even in rural areas, EMS systems with Advanced Life Support crews can stabilize the severely wounded until they can be evacuated to a trauma center by helicopter, putting even more of the population within this protective bubble.

But ironically, residents in the highest-priced neighborhood in human history enjoy no such luxury. Despite only being the equivalent of a quick helicopter ride away, the astronauts and cosmonauts aboard the International Space Station are pretty much on their own when it comes to any traumatic injuries or medical emergencies that might crop up in orbit. While the ISS crews are well-prepared for that eventuality, as we’ll see, there’s only so much we can do right now, and we have a long way to go before we’re ready to perform surgery in space

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Two Decades Of Hackaday In Words

September 29, 2025 by 23 Comments

I think most of us who make or build things have a thing we are known for making. Where it’s football robots, radios, guitars, cameras, or inflatable textile sculptures, we all have the thing we do. For me that’s over the years been various things but has recently been camera hacking, however there’s another thing I do that’s not so obvious. For the last twenty years, I’ve been interested in computational language analysis. There’s so much that a large body of text can reveal without a single piece of AI being involved, and in pursuing that I’ve created for myself a succession of corpus analysis engines. This month I’ve finally been allowed to try one of them with a corpus of Hackaday articles, and while it’s been a significant amount of work getting everything shipshape, I can now analyse our world over the last couple of decades.

The Burning Question You All Want Answered

A graph of "arduino" versis "raspberry", comparing Arduino and Raspberry Pi coverage over time.
Battle of the Boards, over the decades.

A corpus engine is not clever in its own right, instead it will simply give you straightforward statistics in return for the queries you give it. But the thing that keeps me coming back for more is that those answers can sometimes surprise you. In short, it’s a machine for telling you things you didn’t know. To start off, it’s time to settle a Hackaday trope of many years’ standing. Do we write too much about Arduino projects? Into the engine goes “arduino”, and for comparison also “raspberry”, for the Raspberry Pi.

What comes out is a potted history of experimenter’s development boards, with the graph showing the launch date and subsequent popularity of each. We’re guessing that the Hackaday Arduino trope has its origins in 2011 when the Italian board peaked, while we see a succession of peaks following the launch of the Pi in 2012. I think we are seeing renewals of interest after the launch of the Pi 3 and Pi 4, respectively. Perhaps the most interesting part of the graph comes on the right as we see both boards tail off after 2020, and if I had to hazard a guess  as to why I would cite the rise of the many cheap dev boards from China.

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The Impending CRT Display Revival Will Be Televised

September 23, 2025 by 112 Comments

Until the 2000s vacuum tubes practically ruled the roost. Even if they had surrendered practically fully to semiconductor technology like integrated circuits, there was no escaping them in everything from displays to video cameras. Until CMOS sensor technology became practical, proper video cameras used video camera tubes and well into the 2000s you’d generally scoff at those newfangled LC displays as they couldn’t capture the image quality of a decent CRT TV or monitor.

For a while it seemed that LCDs might indeed be just a flash in the pan, as it saw itself competing not just with old-school CRTs, but also its purported successors in the form of SED and FED in particular, while plasma TVs  made home cinema go nuts for a long while with sizes, fast response times and black levels worth their high sale prices.

We all know now that LCDs survived, along with the newcomer in OLED displays, but despite this CRTs do not feel like something we truly left behind. Along with a retro computing revival, there’s an increasing level of interest in old-school CRTs to the point where people are actively prowling for used CRTs and the discontent with LCDs and OLED is clear with people longing for futuristic technologies like MicroLED and QD displays to fix all that’s wrong with today’s displays.

Could the return of CRTs be nigh in some kind of format?

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2025 Hackaday Component Abuse Challenge: Let The Games Begin!

September 16, 2025 by 48 Comments

In theory, all parts are ideal and do just exactly what they say on the box. In practice, everything has its limits, most components have non-ideal characteristics, and you can even turn most parts’ functionality upside down.

The Component Abuse Challenge celebrates the use of LEDs as photosensors, capacitors as microphones, and resistors as heat sources. If you’re using parts for purposes that simply aren’t on the label, or getting away with pushing them to their absolute maximum ratings or beyond, this is the contest for you.

If you committed these sins against engineering out of need, DigiKey wants to help you out. They’ve probably got the right part, and they’re providing us with three $150 gift certificates to give out to the top projects. (If you’re hacking just for fun, well, you’re still in the running.)

This is the contest where the number one rule is that you must break the rules, and the project has to work anyway. You’ve got eight weeks, until Nov 11th. Open up a project over at Hackaday.io, pull down the menu to enter in the contest, and let the parts know no mercy!

Honorable Mention Categories:

We’ve come up with a few honorable mention categories to get your ideas flowing. You don’t have to fit into one of these boxes to enter, but we’ll be picking our favorites in these four categories for a shout-out when we reveal the winners.

  • Bizarro World: There is a duality in almost every component out there. Speakers are microphones, LEDs are light sensors, and peltier coolers generate electricity. Turn the parts upside down and show us what they can do.
  • Side Effects: Most of the time, you’re sad when a part’s spec varies with temperature. Turn those lemons into lemonade, or better yet, thermometers.
  • Out of Spec: How hard can you push that MOSFET before it lets go of the magic smoke? Show us your project dancing on the edge of the abyss and surviving.
  • Junk Box Substitutions: What you really needed was an igniter coil. You used an eighth-watt resistor, and got it hot enough to catch the rocket motor on fire. Share your parts-swapping exploits with us.

Inspiration

Diodes can do nearly anything.  Their forward voltage varies with temperature, making them excellent thermometers. Even the humble LED can both glow and tell you how hot it is. And don’t get us started on the photo-diode. They are not just photocells, but radiation detectors.

Here’s a trick to double the current that a 555 timer can sink. We’d love to see other cases of 555 abuse, of course, but any other IC is fair game.

Resistors get hot. Thermochromic paint changes color with temperature. Every five years or so, we see an awesome new design. This ancient clock of [Sprite_tm]’s lays the foundation, [Daniel Valuch] takes it into the matrix, and [anneosaur] uses the effect to brighten our days.

Of course, thin traces can also be resistors, and resistors can get really hot. Check out [Carl Bujega]’s self-soldering four-layer PCB. And while magnetism is nearly magic, a broken inductor can still be put to good use as a bike chain sensor.

Or maybe you have a new twist on the absolutely classic LEDs-as-light-sensors? Just because it’s been done since the early says of [Forrest Mims] doesn’t mean we don’t want to see your take.

Get out there and show us how you can do it wrong too.

2025 Hackaday Component Abuse Challenge