2025-12-05 11:00:37
It’s relatively easy to understand how optical microscopes work at low magnifications: one lens magnifies an image, the next magnifies the already-magnified image, and so on until it reaches the eye or sensor. At high magnifications, however, that model starts to fail when the feature size of the specimen nears the optical system’s diffraction limit. In a recent video, [xoreaxeax] built a simple microscope, then designed another microscope to overcome the diffraction limit without lenses or mirrors (the video is in German, but with automatic English subtitles).
The first part of the video goes over how lenses work and how they can be combined to magnify images. The first microscope was made out of camera lenses, and could resolve onion cells. The shorter the focal length of the objective lens, the stronger the magnification is, and a spherical lens gives the shortest focal length. [xoreaxeax] therefore made one by melting a bit of soda-lime glass with a torch. The picture it gave was indistinct, but highly magnified.
Besides the dodgy lens quality given by melting a shard of glass, at such high magnification some of the indistinctness was caused by the specimen acting as a diffraction grating and directing some light away from the objective lens. [xoreaxeax] visualized this by taking a series of pictures of a laser shining through a pinhole at different focal lengths, thus getting cross sections of the light field emanating from the pinhole. When repeating the procedure with a section of onion skin, it became apparent that diffraction was strongly scattering the light, which meant that some light was being diffracted out of the lens’s field of view, causing detail to be lost.
To recover the lost details, [xoreaxeax] eliminated the lenses and simply captured the interference pattern produced by passing light through the sample, then wrote a ptychography algorithm to reconstruct the original structure from the interference pattern. This required many images of the subject under different lighting conditions, which a rotating illumination stage provided. The algorithm was eventually able to recover a sort of image of the onion cells, but it was less than distinct. The fact that the lens-free setup was able to produce any image at all is nonetheless impressive.
To see another approach to ptychography, check out [Ben Krasnow’s] approach to increasing microscope resolution. With an electron microscope, ptychography can even image individual atoms.
2025-12-05 08:00:05
Have you ever tipped all the stray bits of solder out of your tip cleaner by mistake? [MisterHW] is here with a bit pf paraffin wax to save the day.
Hand soldering can be a messy business, especially when you wipe the soldering iron tip on those common brass wool bundles that have largely come to replace moist sponges. The Weller Dry Cleaner (WDC) is one of such holders for brass wool, but the large tray in front of the opening with the brass wool has confused many as to its exact purposes. In short, it’s there so that you can slap the iron against the side to flick contaminants and excess solder off the tip.
Along with catching some of the bits of mostly solder that fly off during cleaning in the brass wool section, quite a lot of debris can be collected this way. Yet as many can attest to, it’s quite easy to flip over brass wool holders and have these bits go flying everywhere.
That’s where [MisterHW]’s pit of particulate holding comes into play, using folded sheet metal and some wax (e.g. paraffin) to create a trap that serves to catch any debris that enters it and smother it in the wax. To reset the trap, simply heat it up with e.g. the iron and you’ll regain a nice fresh surface to capture the next batch of crud.
As the wax is cold when in use, even if you were to tip the holder over, it should not go careening all over your ESD-safe work surface and any parts on it, and the wax can be filtered if needed to remove the particulates. When using leaded solder alloys, this setup also helps to prevent lead-contamination of the area and generally eases clean-up as bumping or tipping a soldering iron stand no longer means weeks, months or years of accumulations scooting off everywhere.
2025-12-05 05:00:31
Wi-Fi! It’s everywhere, and yet you can’t really see it, by virtue of the technology relying on the transmission of electromagnetic waves outside the visual spectrum. Never mind, though, because you can always build yourself a Wi-Fi analyzer to get some insight into your radio surroundings, as demonstrated by [moononournation].
The core of the build is the ESP32-C5. The popular microcontroller is well-equipped for this task with its onboard dual-band Wi-Fi hardware, even if the stock antenna on most devboards is a little underwhelming. [moononournation] has paired this with a small rectangular LCD screen running the ILI9341 controller. The graphical interface is drawn with the aid of the Arduino_GFX library. It shows a graph of access points detected in the immediate area, as well as which channels they’re using and their apparent signal strength.
If you’re just trying to get a basic read on the Wi-Fi environment in a given locale, a tool like this can prove pretty useful. If your desires are more advanced, you might leap up to tinkering in the world of software defined radio. Video after the break.
2025-12-05 03:30:44
Probably the biggest story in the world of old cars over the past couple of weeks has been the surfacing of a GM EV1 electric car for sale from an auto salvage yard. This was the famous electric car produced in small numbers by the automaker in the 1990s, then only made available for lease before being recalled. The vast majority were controversially crushed with a few units being donated to museums and universities in a non-functional state.
Finding an old car isn’t really a Hackaday story in itself, but now it’s landed in [The Questionable Garage]. It’s being subjected to a teardown as a prelude to its restoration, offering a unique opportunity to look at the state of the art in 1990s electric automotive technology.
The special thing about this car is that by a murky chain of events it ended up as an abandoned vehicle. GM’s legal net covers the rest of the surviving cars, but buying this car as an abandoned vehicle gives the owner legal title over it and frees him from their restrictions. The video is long, but well worth a watch as we see pieces of automotive tech never before shown in public. As we understand it the intention is to bring it to life using parts from GM’s contemporary S10 electric pickup truck — itself a rare vehicle — so we learn quite a bit about those machines too.
Along the way they find an EV1 charger hiding among a stock of pickup chargers, take us through the vehicle electronics, and find some galvanic corrosion in the car’s structure due to water ingress. The windscreen has a huge hole, which they cover with a plastic wrap in order to 3D scan so they can create a replacement.
This car will undoubtedly become a star of the automotive show circuit due to its unique status, so there will be plenty of chances to look at it from the outside in future. Seeing it this close up in parts though is as unique an opportunity as the car itself. We’ve certainly seen far more crusty conventional cars restored to the road, but without the challenge of zero parts availability and no donor cars. Keep an eye out as they bring it closer to the road.
2025-12-05 02:00:56
Some like it flat, and there’s nothing wrong with that. What you are looking at is the first prototype of Atlas by [AsicResistor], which is still a work in progress. [AsicResistor] found the Totem to be a bit cramped, so naturally, it was time to design a keyboard from the ground up.
This travel-friendly keyboard has 34 keys and dual trackpoints, one on each half. If the nubbin isn’t your thing, there’s an optional, oversized trackball, which I would totally opt for. But I would need an 8-ball instead, simply because that’s my number.
A build video is coming at some point, so watch the GitHub, I suppose, or haunt r/ergomechkeyboards.
Flat as it may be, I would totally at least give this keyboard a fair chance. There’s just something about those keycaps, for starters. (Isn’t it always the keycaps with me?) For another, I dig the pinky stagger. I’m not sure that two on each side is nearly enough thumb keys for me, however.
Sitting at a keyboard all day isn’t great for anyone, but adding in some leg and/or foot movement throughout the day is a good step in the right direction. Don’t want to just ride a bike all day under your desk? Add something useful like foot pedals.
Brain-wise, it has a wireless macro keyboard and an encoder from Ali, but [a__b] plans to upgrade it to a nice!nano in order to integrate it with a Glove80.
Although shown with a NautiCroc, [a__b] says the wheel works well with socks on, or bare feet. (Take it from me, the footfeel of pedals is much more accurate with no shoes on.) Interestingly, much of the inspiration was taken from sewing machines.
As of this writing, [a__b] has mapped all keys using BetterTouchTool for app-specific action, and is out there happily scrolling through pages, controlling the volume, and navigating YouTube videos. Links to CAD and STLs are coming soon.
As you might imagine and [Flat-Razzmatazz-672] can attest, 3D printing LEGO is weird. These studs are evidently >= 5% bigger than standard studs, because if you print it as is, the LEGO won’t fit right.
Via reddit
Do you rock a sweet set of peripherals on a screamin’ desk pad? Send me a picture along with your handle and all the gory details, and you could be featured here!
Although lovely to gaze upon, the North’s typewriter was a doomed attempt at creating a visible typewriter. That is, one where a person could actually see what they were typing as they typed it.
North’s achieved this feat through the use of vertical typebars arranged in a semi-circle that would strike down onto the platen from behind, making it a rear down-striker.
In order for this arrangement to work, the paper had to be loaded, coiled into one basket, and it was fed into another, hidden basket while typing. This actually allowed the typist to view two lines at a time, although the unfortunate ribbon placement obstructed the immediate character.
The story of North’s typewriter is a fairly interesting one. For starters, it was named after Colonel John Thomas North, who wasn’t really a colonel at all. In fact, North had very little to do with the typewriter beyond bankrolling it and providing a name.
North started the company by purchasing the failed English Typewriter Company, which brought along with it a couple of inventors, who would bring the North’s to fruition. The machine was made from 1892 to 1905. In 1896, North died suddenly while eating raw oysters, though the cause of death was likely heart failure. As he was a wealthy, unpopular capitalist, conspiracy theories abounded surrounding his departure.
It’s true, the MoErgo Glove80 is great for travel. And admittedly, it’s kind of big, both in and out of its (very nice) custom zipper case. But you asked, and MoErgo listened. And soon enough, there will be a new option for even sleeker travel, the Go60. Check out the full spec sheet.
You may have noticed that it’s much flatter than the Glove80, which mimics the key wells of a Kinesis Advantage quite nicely.
Don’t worry, there are removable palm rests that are a lot like the Glove80 rests. And it doesn’t have to be flat –there is 6-step magnetic tenting (6.2° – 17°), which snaps on or off in seconds. The palm rests have 7-step tenting (6°-21.5°), and they come right off, too.
Let’s talk about those trackpads. They are Cirque 40 mm Glidepoints. They aren’t multi-touch, but they are fully integrated into ZMK and thus are fully programmable, so do what you will.
Are you as concerned about battery life as I am? It’s okay — the Go60 goes fully wired with a TRRS cable between the halves, and a USB connection from the left half to the host. Although ZMK did not support this feature, MoErgo sponsored the founder, [Pete], to develop it, and now it’s just a feature of ZMK. You’re welcome.
Interested? The Go60 will be on Kickstarter first, and then it’ll be available on the MoErgo site. Pricing hasn’t quite been worked out yet, so stay tuned on that front.
Via reddit
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2025-12-05 00:30:04
One of the major difficulties in studying electricity, especially when compared to many other physical phenomena, is that it cannot be observed directly by human senses. We can manipulate it to perform various tasks and see its effects indirectly, like the ionized channels formed during lightning strikes or the resistive heating of objects, but its underlying behavior is largely hidden from view. Even mathematical descriptions can quickly become complex and counter-intuitive, obscured behind layers of math and theory. Still, [lcamtuf] has made some strides in demystifying aspects of electricity in this introduction to analog filters.
The discussion on analog filters looks at a few straightforward examples first. Starting with an resistor-capacitor (RC) filter, [lcamtuf] explains it by breaking its behavior down into steps of how the circuit behaves over time. Starting with a DC source and no load, and then removing the resistor to show just the behavior of a capacitor, shows the basics of this circuit from various perspectives. From there it moves into how it behaves when exposed to a sine wave instead of a DC source, which is key to understanding its behavior in arbitrary analog environments such as those involved in audio applications.
There’s some math underlying all of these explanations, of course, but it’s not overwhelming like a third-year electrical engineering course might be. For anyone looking to get into signal processing or even just building a really nice set of speakers for their home theater, this is an excellent primer. We’ve seen some other demonstrations of filtering data as well, like this one which demonstrates basic filtering using a microcontroller.
