Interesting Optics Make This Laser Engraver Fit In A Pocket

July 24, 2022 by Dan Maloney 37 Comments

We’re going to start this post with a stern warning: building a laser engraver that can fit in your pocket is probably not a wise idea. Without any safety interlocks and made from lightweight components as it is, this thing could easily tip over and sear a retina before you’d even have time to react. You definitely should not build this, or even be in the same room with it. Got it?

Safety concerns aside, [DAZ] has taken a pretty neat approach to making this engraver, eschewing the traditional X-Y gantry design in favor of something more like the galvanometers used for laser projectors, albeit completely homebrew and much, much slower than commercial galvos. Built mostly of 3D-printed parts, the scanning head of this engraver uses a single mirror riding on an angled block attached to gimbals with two degrees of freedom. The laser module and mirror gimbals are mounted on a stand made of light aluminum so that the whole thing is suspended directly over a workpiece; the steppers slew the mirror to raster the beam across the workpiece and burn a design.

The video below shows it at work, and again, we have to stress that this is about as close to this build as you should get. It shouldn’t be too hard to add some safety features, though — at a minimum, we’d like to see a tilt-switch that kills power if it’s knocked over, and maybe some kind of enclosure. Sure, that would probably spoil the pocketability of the engraver, but is that really a feature valuable enough to risk your eyesight for?

If there’s a laser build in your future, please read our handy guide to homebrew laser cutter safety — before you can’t.

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Machine Learning Baby Monitor Prevents The Hunger Games

July 23, 2022 by Dan Maloney 25 Comments

Newborn babies can be tricky to figure out, especially for first-time parents. Despite the abundance of unsolicited advice proffered by anyone who ever had a baby before — and many who haven’t — most new parents quickly get in sync with the baby’s often ambiguous signals. But [Caleb] took his observations of his newborn a step further and built a machine-learning hungry baby early warning system that’s pretty slick.

Normally, babies are pretty unsubtle about being hungry, and loudly announce their needs to the world. But it turns out that crying is a lagging indicator of hunger, and that there are a host of face, head, and hand cues that precede the wailing. [Caleb] based his system on Google’s MediaPipe library, using his baby monitor’s camera to track such behaviors as lip smacking, pacifier rejection, fist mouthing, and rooting, all signs that someone’s tummy needs filling. By putting together a system to recognize these cues and assign a weight to them, [Caleb] now gets a text before the baby gets to the screaming phase, to the benefit of not only the little nipper but to his sleep-deprived servants as well. The video below has some priceless bits in it; don’t miss [Baby Caleb] at 5:11 or the hilarious automatic feeder gag at the end.

We’ve seen some interesting videos from [Caleb] recently, mostly having to do with his dog’s bathroom habits and getting help cleaning up afterward. We can only guess how those projects will be leveraged when this kid gets a little older and starts potty training.

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Purpose-Built Plotter Pitches In To Solve Wordblitz On Your Phone

July 23, 2022 by Dan Maloney No comments

It seems like most hackers have never played a game without at least wondering how to cheat at it. It’s not that we’re a dishonest lot, at least not as a rule. It’s more that most games hold less challenge for us than does figuring out how to reverse engineer the game’s mechanics. We don’t intend to cheat; it just sort of happens.

Or at least that’s the charitable way to look at such smartphone game cheats as this automated word-search puzzle solver. The game is Wordblitz, which is basically an implementation of classic Boggle along with extra features to release more dopamine and keep you playing. Not one to fall for that trick, [ghettobastler] whipped up a quick X-Y gantry from MDF using a laser cutter, added a stylus in the form of a cotton swab tipped with aluminum foil, and a vision system based on a simple web camera. The bed of the gantry has a capacitive plate so the stylus can operate the phone, along with a frame of ArUco fiducial marker to aid in locating the phone.

A Raspberry Pi handles the machine vision part of the process, which uses OpenCV to estimate the phone’s location and extract the current game tiles. The words in the game field are located by a solver that [ghetto] had previously written; a script then streams G-code to the plotter to peck out the answers at blazing speed, or at least faster than even [Peggy Hill] could manage. See the video below for a sample game being solved.

One word of warning if you choose to build this: [ghettobastler]’s puzzle-solving algorithm is based on a French dictionary, so you’ll have to re-teach it for other languages. But whatever language it’s in, this reminds us a bit of some of the Wordle solvers we’ve seen recently.

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SATAn Turns Hard Drive Cable Into Antenna To Defeat Air-Gapped Security

July 22, 2022 by Dan Maloney 19 Comments

It seems like [Mordechai Guri]’s lab at Ben-Gurion University is the place where air-gapped computers go to die, or at least to give up their secrets. And this hack using a computer’s SATA cable as an antenna to exfiltrate data is another example of just how many side-channel attacks the typical PC makes available.

The exploit, deliciously designated “SATAn,” relies on the fact that the SATA 3.0 interface used in many computers has a bandwidth of 6.0 Gb/s, meaning that manipulating the computer’s IO would make it possible to transmit data from an air-gapped machine at around 6 GHz. It’s a complicated exploit, of course, and involves placing a transmitting program on the target machine using the usual methods, such as phishing or zero-day exploits. Once in place, the transmitting program uses a combination of read and write operations on the SATA disk to generate RF signals that encode the data to be exfiltrated, with the data lines inside the SATA cable acting as antennae.

SATAn is shown in action in the video below. It takes a while to transmit just a few bytes of data, and the range is less than a meter, but that could be enough for the exploit to succeed. The test setup uses an SDR — specifically, an ADALM PLUTO — and a laptop, but you can easily imagine a much smaller package being built for a stealthy walk-by style attack. [Mordechai] also offers a potential countermeasure for SATAn, which basically thrashes the hard drive to generate RF noise to mask any generated signals.

While probably limited in its practical applications, SATAn is an interesting side-channel attack to add to [Dr. Guri]’s list of exploits. From optical exfiltration using security cameras to turning power supplies into speakers, the vulnerabilities just keep piling up.

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Cut Just About Anything With This Combination Lathe And Wire EDM

July 20, 2022 by Dan Maloney 18 Comments

They say that if you have a lathe, you have every other machine tool too. To some degree, that’s true — you can make almost anything on a lathe, including another lathe, and even parts best made on other machine tools can usually be made on a lathe in a pinch. But after seeing this lathe attachment for a DIY electric discharge machining tool, we might be inclined to see the EDM as the one machine tool to rule them all.

Now, we’ll admit that the job [BAXEDM] built this tool for might be a little contrived. He wanted to make some custom hex inserts for his Swiss Army knife, which seem like they’d have been pretty easy to make from hex bar stock in a conventional lathe. Then again, hardened steel is the kind of material that wire EDM was made for, and there seem to be many use cases for an attachment that can spin a workpiece against an EDM cutting wire.

That was really the trick of this build — spinning a part underwater. To accomplish this, [BAXEDM] built a platform to carry a bearing block that supports a standard ER-25 collet, with a bracket that holds a stepper clear of the water in the EDM cutting tank. There are plenty of 3D printed insulators too, to keep most of the attachment electrically isolated from the EDM current, plus exotic parts like ceramic bearings that won’t corrode under water. There were a ton of other considerations, too; [BAXEDM] goes through the long iterative design process in the video below, as well as taking his new tool for a literal spin starting at about the 27:00 mark.

If you’re intrigued by what EDM can accomplish — and who wouldn’t be? — but you need more background on the process, we’ve got you covered.

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Modular Z80 Really Racks Up The Retrocomputer Cred

July 19, 2022 by Dan Maloney 24 Comments

Very few retrocomputing projects are anything other than a labor of love. There’s really no practical reason to build a computer that is woefully inadequate for just about any task compared to even an entry-level PC today. But the lack of a practical reason to do something rarely stops a hacker, as with this nifty modular Z80-based rack computer.

Actually, there’s at least one area where retrocomputers excel compared to their modern multi-core gigahertz counterparts — and that’s nostalgia. That’s what [Ricardo Kaltchuk] was going for with his build, which started by finding a Z80 and an Intel 8251 USART in his parts bin. Those formed the core of what would become the “Proton” computer, a modular beauty built around 7 cm by 10 cm PCBs that plug into a backplane inside a rack made from aluminum angle. Aside from the power supply and the Z80 CPU, other modules include a RAM card with a zero insertion force socket for an EPROM, a mass-storage module sporting a 128 MB Compact Flash card, plus modules for standard serial and I2C comms.

The fit and finish are excellent, and the performance is impressive. The Proton runs CP/M and boasts a ton of old applications that will bring back some memories, like SuperCalc and dBase. We’d venture a bet that WordStar is in there someplace, or easily could be. The video below is a little rough, but shows everything off really well.

In some ways, the Proton reminds us of the RC2014, but its fit and finish are what bring this build home. That’s not to take away from the work [Ricardo] obviously put into documentation, though. The 62-page manual has every detail of every module, plus instructions for building one of your own.

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Hackaday Links: July 17, 2022

July 17, 2022 by Dan Maloney 9 Comments

Webb’s first deep-field image. Source: NASA

The folks at NASA are taking a well-deserved victory lap this week after the splashy reveal of the first scientific images from the James Webb Space Telescope. As we expected, the first public release included a lot of comparisons to images obtained from Hubble, as the general public understandably sees Webb as the successor to the venerable space telescope, now in its third decade of service. So for a “let’s see what this baby can do” image, they turned Webb loose on a tiny patch of sky in the southern hemisphere containing galactic cluster SMACS 0723, and sent back images and spectroscopic data from galaxies up to 13 billion light years away. There are plenty of analyses of Webb’s deep field and the other images in the first release, but we particularly liked the takes by both Anton Petrov and Dr. Becky. They both talk about the cooler scientific aspects of these images, and how Webb is much more than just a $10 billion desktop image generator.

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