This Gesture Sensor Is Precise, Cheap, Well-Hidden

March 1, 2025 by Arya Voronova 22 Comments

In today’s “futuristic tech you can get for $5”, [RealCorebb] shows us a gesture sensor, one of the sci-fi kind. He was doing a desktop clock build, and wanted to add gesture control to it – without any holes that a typical optical sensor needs. After some searching, he’s found Microchip’s MGC3130, a gesture sensing chip that works with “E-fields”, more precise than the usual ones, almost as cheap, and with a lovely twist.

The coolest part about this chip is that it needs no case openings. The 3130 can work even behind obstructions like a 3D-printed case. You do need a PCB the size of a laptop touchpad, however — unlike the optical sensors easy to find from the usual online marketplaces. Still, if you have a spot, this is a perfect gesture-sensing solution. [RealCorebb] shows it off to us in the demo video.

This PCB design is available as gerbers+bom+schematic PDF. You can still order one from the files in the repo. Also, you need to use Microchip’s tools to program your preferred gestures into the chip. Still, it pays off, thanks to the chip’s reasonably low price and on-chip gesture processing. And, [RealCorebb] provides all the explanations you could need, has Arduino examples for us, links all the software, and even provides some Python scripts! Touch-sensitive technology has been getting more and more steam in hacker circles – for instance, check out this open-source 3D-printed trackpad.

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Using Four Rolls Of Film To Make One Big Photo

March 1, 2025 by Lewin Day 12 Comments

Typically, if you’re shooting 35 mm film, you’re using it in an old point-and-shoot or maybe a nice SLR. You might even make some sizeable prints if you take a particularly good shot. But you can get altogether weirder with 35 mm if you like, as [Socialmocracy] demonstrates with his “extreme sprocket hole photography” project (via Petapixel).

The concept is simple enough. [Socialmocracy] wanted to expose four entire rolls of 35 mm film all at the same time in one single shot. To be absolutely clear, we’re not talking about exposing a frame on each of four rolls at once. We’re talking about a single exposure covering the entire length of all four films, stacked one on top of the other.

To achieve this, an old-school Cirkut No.6 Outfit camera was pressed into service. It’s a large format camera, originally intended for shooting panoramas. As the camera rotated around under the drive of a clockwork motor, it would spool out more film to capture an image.

[Socialmocracy] outfitted the 100-year-old camera with a custom 3D-printed spool that could handle four rolls of film at once, rather than its usual wide single sheet of large format film. This let the camera shoot its characteristic panoramas, albeit spread out over multiple rolls of film, covering the sprocket holes and all. Hence the name—”extreme sprocket hole photography.”

It’s a neat build, and one that lets [Socialmocracy] use more readily available film to shoot fun panoramas with this old rig. We’ve featured some other great film camera hacks over the years, too, like this self-pack Polaroid-style film. Video after the break.

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The Bus Pirate 5 Sure Can Glitch

March 1, 2025 by Arya Voronova 2 Comments

Own a Bus Pirate 5? Now, it can do power glitching, thanks to [Matt Brugman’s] demo and contributions to the stock code. This is also a great demo of Bus Pirate’s capabilities and programmability! All you need is the Bus Pirate and a generic Arduino – load a glitch-vulnerable code example into the Arduino, get yourself a generic FET-based glitching setup, and you too can play.

The Arduino board outputs data over UART, and that’s used as a trigger for the Bus Pirate’s new glitch feature – now mainline, thanks to [Matt]’s pull request. It’s pretty feature-complete, too — all parameters are configurable, it can vary the glitching interval, as one would want, and the code checks for success conditions so that it can retry glitching automatically.

In this demo, it only took six consecutive attempts to successfully glitch the ATMega328P – wouldn’t you know it, the code that got glitched was pulled almost wholesale from an IoT device. Glitching remains an underappreciated vector for reverse-engineering, and there’s really no shortage of hacks it allows you to do – get yourself a FET, a Bus Pirate, or maybe just an ESP8266, and join the glitching-aware hackers club!

Want to know more about the Bus Pirate 5? Check out our hands-on review of the hacker multi-tool from last year.

An image showing an original grey and blue Sony Walkman with the text "1970" below it, and an arrow pointing to the right of it at a much smaller blue Walkman with the text "2000" underneath it, and a final arrow pointing to the right to a bright orange cassette player by We Are Rewind in a man's hand with the text "now" beneath it.

Why Are Cassette And CD Players So Big Now?

March 1, 2025 by Navarre Bartz 66 Comments

The early 2000s were the halcyon days of physical media. While not as svelte as MP3 players became, why are those early 2000s machines smaller than all the new models popping up amidst the retro audio craze?

We’ve bemoaned the end of the electromechanical era before, and the Verge recently interviewed the people at We Are Rewind and Filo to get the skinny on just why these newer cassette and CD players aren’t as small as their predecessors. It turns out that all currently produced cassette players use the same mechanism with some small tweaks in materials (like metal flywheels in these higher quality models) because the engineering required to design a smaller and better sounding alternative isn’t warranted by the niche nature of the cassette resurgence.

A similar fate has befallen the laser head of CD mechanisms, which is why we don’t have those smooth, rounded players anymore. Economies of scale in the early 2000s mean that even a cheap player from that era can outperform a lot of the newer ones, although you won’t have newer features like Bluetooth to scandalize your audiophile friends. A new Minidisc player is certainly out of the question, although production of discs only ended this February.

If you’re looking to get back into cassettes, this masterclass is a good place to start. If you don’t fancy any of the players the Verge looked at, how about rolling your own incarnation with the guts from a vintage machine or just going for the aesthetic if cassettes aren’t your jam?

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SteamVR Controller Controlling Addressable LEDs

March 1, 2025 by Lewin Day 6 Comments

[Chris] had an idea. When playing VR games like BeatSaber, he realized that spectators without headsets weren’t very included in the action. He wanted to create some environmental lighting that would make everyone feel more a part of the action. He’s taken the first steps towards that goal, interfacing SteamVR controllers with addressable LEDs.

Armed with Python, OpenVR, and some help from ChatGPT, [Chris] got to work. He was soon able to create a mapping utility that let him create a virtual representation of where his WLED-controlled LED strips were installed in the real world. Once everything was mapped out, he was able to set things up so that pointing the controller to a given location would light the corresponding LED strips. Wave at the windows, the strips on that wall light up. Wave towards the other wall, the same thing happens.

Right now, the project is just a proof of concept. [Chris] has enabled basic interactivity with the controllers and lights, he just hasn’t fully built it out or gamified it yet. The big question is obvious, though—can you use this setup while actually playing a game?

“I just found the OpenVR function/object that allows it to act as an overlay, meaning it can function while other games are working,” [Chris] told me. “My longer term goals would be trying to interface more with a game directly such as BeatSaber, and the light in the room would correspond with the game environment.”

We can’t wait to see where this goes next. We fully expect flashy LED room setups to become the norm at VR cafes hosting BeatSaber competitions in future. We’ve featured plenty of other coverage of VR lately, too.

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Practice While You Work

March 1, 2025 by Elliot Williams 19 Comments

This week, I had to do something I haven’t done in a long, long time: make myself a custom PCB the old-fashioned way, with laser toner and etchant. The reason? I bought a horrible K40 laser cutter, and the motion controller doesn’t seem to be able to do acceleration control, which means the machine rams full speed into and out of 90 degree corners, for instance. It sounds awful, and it dramatically limits how fast the laser cutter can run.

The plan, then, is to use a controller based on the wonderful FluidNC, but that meant making an adapter board for the flat-flex cable that connects to the X carriage, and the connector has 2 mm pin spacings instead of the usual 2.54 mm, and it just doesn’t fit into any prototyping boards that I have lying around. Besides, a custom PCB adapter board just looks neater.

I wasn’t confident that I could align and drill the dozen small holes for the flat-flex connector; they didn’t have much extra space around them for the copper pads. These holes had to be dead on, or risk ripping them up. And this is where I heard the voice of my old Jedi master.

When you have a tricky operation coming up that requires more precision than you’re immediately comfortable with, you can practice on the other parts of the project that don’t demand that much precision. Pretending that they do, and taking all the care that you can, gets you in shape to tackle the truly critical bits, and if you mess up a little on the easy stuff, it’s not a problem. I had more than a few pin-headers and other random holes to drill for practice anyway.

Now of course, you could always be giving all of your projects 100% all of the time, if time is never of the essence and effort is free. In the real world, you don’t always want to work at maximum precision. Good enough is often good enough.

But there’s also a time and a place for practicing precision, especially when you see a need for it up ahead. Drilling the big holes dead center got me back in the swing of things, and they needed to get drilled one way or the other. I find it useful to think about the job first, plan ahead where the tricky bits are going to be, and then treat the “easy” stuff along the way as practice for the more demanding operations. Hope you do too!

A PCR machine with its side cover taken off exposing its guts, and the tray extended out

Making A PCR Machine Crypto Sign Its Results

March 1, 2025 by Arya Voronova 20 Comments

Money, status, or even survival – there’s no shortage of incentives for faking results in the scientific community. What can we do to prevent it, or at least make it noticeable? One possible solution is cryptographic signing of measurement results.

Here’s a proof-of-concept from [Clement Heyd] and [Arbion Halili]. They took a ThermoFisher Scientific 7500 Fast PCR (Polymerase Chain Reaction) machine, isolated its daughter-software, and confined it into a pipeline that automatically signs each result with help of a HSM (Hardware Security Module).

A many machines do, this one has to be paired to a PC, running bespoke software. This one’s running Windows XP, at least! The software got shoved into a heavily isolated virtual machine running XP, protected by TEE (Trusted Execution Environment). The software’s output is now piped into a data diode virtual serial port out of the VM, immediately signed with the HSM, and signed data is accessible through a read-only interface. Want to verify the results’ authenticity? Check them against the system’s public key, and you’re golden – in theory.

This design is just a part of the puzzle, given a typical chain of custody for samples in medical research, but it’s a solid start – and it happens to help make the Windows XP setup more resilient, too.

Wondering what PCR testing is good for? Tons of things all over the medical field, for instance, we’ve talked about PCR in a fair bit of detail in this article about COVID-19 testing. We’ve also covered a number of hacker-built PCR and PCR-enabling machines, from deceivingly simple to reasonably complex!