A 3D-printed clock that uses flaps for the digits that get rotated.

Non-Split-Flap Clock Does It With Fewer Flaps

As cool as split-flap clocks and displays are, they do have a few disadvantages. The mechanism sticks out on the side, and the whole thing relies on gravity. Some people don’t care for the visual split in the middle of each digit that comes as a result. And their cousins, the Numechron clocks? Those wheels, especially the hours wheel, are really big compared to the size of what they display, so the clock housings are huge by comparison.

[shiura] decided to re-invent the digital display and came up with this extremely cool spinning flap mechanism that uses a lip to flip each flap after it is shown. Thanks to this design, only half the number of flaps are needed. Not only is the face of the clock able to be much larger compared to the overall size of the thing, the whole unit is quite shallow. Plus, [shiura] tilted the display 15° for better visibility.

If you want to build one of these for yourself, [shiura] has all the STLs available and some pretty great instructions. Besides the printed parts, you don’t need much more than the microcontroller of your choice and a stepper motor. Check out the demo/build video after the break, and stick around for the assembly video.

Don’t mind the visual split in the numbers? Check out this split-flap clock that uses a bunch of magnets.

Continue reading “Non-Split-Flap Clock Does It With Fewer Flaps”

A Google Pixel 7 with a detachable Bluetooth keyboard.

BlueBerry Is A Smartphone-Agnostic Keyboard Firmware

If you’re anything like us, you really, really miss having a physical keyboard on your phone. Well, cry no more, because [Joe LiTrenta] has made it possible for any modern smartphone whatsoever to have a detachable, physical keyboard and mouse at the ready. [Joe] calls this creation the BlueBerry.

A couple of metal plates and a mag-safe pop socket connect a Bluetooth keyboard to a Google Pixel 7. The keyboard/mouse combo in question is a little BlackBerry Bluetooth number from ZitaoTech which is available on Tindie, ready to go in a 3D printed case. What [Joe] has done is to create a custom ZMK-based firmware that allows the keyboard be device-agnostic.

In order to easily mount the keyboard to the phone and make it detachable, [Joe] used adhesive-backed metal mounting plates on both the phone and the keyboard, and a mag-safe pop socket to connect the two. The firmware makes use of layers so everything is easily accessible.

Check out the demo video after the break, which shows the board connected to a Google Pixel 7. It makes the phone comically long, but having a physical keyboard again is serious business, so who’s laughing now? We’d love to see a keyboard that attaches to the broad side of the phone, so someone get on that. Please?

Do you have a PinePhone? There’s an extremely cute keyboard for that.

Continue reading “BlueBerry Is A Smartphone-Agnostic Keyboard Firmware”

Kaffa Roastery founder Svante Hampf shows a bag of their AI-conic coffee blend.

AI-Created Coffee Blend Isn’t Terrible

Weren’t we just talking about coffee-based sacrilege the other day? Here’s something to make the single-origin bean snobs chew their espresso cups: an artisan roastery in Helsinki is offering a coffee blend created by artificial intelligence called AI-conic. The idea, of course, is that technology will lighten the workload needed to produce coffee.

This is an interesting development because Finland consumes the most coffee in the world, according to the International Coffee Organization. Coffee roasting is a highly-valued traditional artisan profession there, so it stands to reason that they might turn to technology for help.

Just like with scotch whisky, there’s nothing wrong with coffee blends outright. Bean blends are good for consistency, when you want every cup to taste pretty much exactly the same. Single-origin beans, though, are traceable to one location, and as a result, they usually have a distinct flavor based on the climate they’re grown in.

If you’re new to coffee, blends are a nice, safe way to start out. And, interestingly, the AI chose to make the blend out of four different types of beans instead of the usual two or three, despite being tasked with creating a blend that would suit the palates of coffee enthusiasts. But the coffee experts agreed that the AI blend was “perfect” and needed no human intervention. We probably won’t be getting to Finland anytime soon, so if you try it, let us know how it tastes!

Do you like cold brew? How would you like to be able to brew some in just three minutes?

A DIY split-flap clock in red, black, and white.

Split-Flap Clock Uses Magnets Everywhere

While split-flap alarm clocks once adorned heavy wood nightstands in strong numbers, today the displays are most commonly found in train stations and airports. Hey, at least they’re still around, right? Like many of us, [The Wrench] has always wanted to make one for themselves, but they actually got around to doing it.

A DIY split-flap clock and its magnetic base.This doesn’t seem like a beginner-friendly project, but [The Wrench] says they were a novice in 3D design and so used Tinkercad to design all the parts. After so many failures, they settled on a design for each unit that uses a spool to attach the flaps, which is turned by a stepper motor.

A small neodymium magnet embedded in the primary gear and a Hall effect sensor determine where the stepper motor is, and in turn, which number is displayed. Everything is handled by an Arduino Nano on a custom PCB.

Aside from the sleek, minimalist look, our favorite part is that [The Wrench] used even more magnets to connect each display segment to the base. You may have noticed that there are only three segments, because the hours are handled by a single display that has flaps for 10, 11, and 12. This makes things simpler and gives the clock an interesting look. Be sure to check out the build video after the break.

Want to build a more complicated clock? Try suspending sand digits in the air with persistence of vision.

Continue reading “Split-Flap Clock Uses Magnets Everywhere”

A Planck-inspired 40% ortholinear keyboard.

DIY Keyboard Can Handle Up To Three Host Devices

Here’s a story that may be familiar: [der-b] is a Linux developer who is forced two carry two laptops — one for work with unavoidable work stuff on it, and one for software development. Unfortunately this leads to keyboard confusion between the two when one is connected to an external display.

In an attempt to overcome this, [der-b] designed a keyboard that can be connected to more than one device at a time, despite ultimately thinking that this will lead to another layer of confusion. The point was to try to make something as lightweight as possible, since carrying two laptops is already a struggle. As a bonus, this project was a learning experience for soldering SMD parts.

The keyboard itself is based on the Planck and uses an ATMega32u4 running QMK firmware, so that means it’s a 40% ortholinear with 48 keys total. [der-b] used low-profile Cherry MX switches to keep things sleek.

In order to switch between different host devices, [der-b] uses shortcuts as you’ll see in the short video after the break. This is accomplished with a FSUSB36 IC on the USB connections between the ATMega and the host.

[der-b] encountered a spate of issues while building this keyboard, which you can read all about in the blog post. We love to see transparency when it comes to your write-ups, especially when the projects become learning experiences. (Aren’t they all?) But if 48 keys aren’t nearly enough for you, check out this learning-experience keyboard build.

Continue reading “DIY Keyboard Can Handle Up To Three Host Devices”

A pile of red Swiss Army knives, probably collected by TSA.

Introducing The Swiss Army… Tool?

You’ve probably used one for everything from opening packages to stripping wires in a pinch (because you know better than to use your teeth). We’re talking about the blade of the iconic Swiss Army knife. And while there are many different models out there, they all feature at least one knife among their utensils. Until now.

Citing pressure due to the increase in worldwide knife violence, the company announced that they’ll be releasing a new range of tools without blades. Carl Elsner, fourth-generation CEO of Swiss Army knife maker Victorinox, is also concerned about increasing regulations surrounding knives at sporting events and other activities. And he has a point: according to the UN’s Global Study on Homicide 2023 (PDF), 30% of European homicides were committed with some type of sharp object.

In an interview with The Guardian, Elsner spoke of creating more specialized tools, such as one for cyclists, who don’t necessarily need a blade. He also mentioned that Victorinox have a tool specifically for golfers, but we’d like to point out that it features, among other things, a knife.

It’s going to be a long time before people stop assuming that the skinny red thing in your pocket contains a knife, especially at the airport. What TSA agent is going to take the time to check out your tool? They’re going to chuck it in the bucket with the rest of them. Would you consider buying a blade-less multi-tool? Let us know in the comments.

Don’t have much need for a knife? Here’s a bench tool that has it all.

(Main and thumbnail photos via Unsplash)

Much Faster Cold Brew Through Cavitation

Some coffee snobs might call this sacrilege. Cold brew is supposed to take a long time — that’s part of how it gets its characteristic smoothness. But a group of engineers from the University of New South Wales (UNSW Sydney) have figured out a way to cut the time down from several hours to a mere three minutes, using ultrasonic waves.

Diagram showing the parts of the faster cold brew system -- the portafilter of a Breville espresso machine, plus a transducer and horn.Typically, the cold brew coffee process takes between 12 and 24 hours. Enough time to steep the grounds and extract the flavors without the benefit of hot water. This is how it differs from iced coffee, which is brewed hot and poured over ice.

Interestingly, the UNSW Sydney engineers’ process uses a typical prosumer-grade espresso machine and involves blasting the portafilter with a transducer and a horn. This transforms the coffee basket into a sonoreactor. Sound waves at a frequency of 38.8 kHz are injected at multiple points through the walls, generating acoustic cavitation within. You can read all about it in Ultrasonics Sonochemistry.

That’s not even the most exciting part. The study found that this arrangement is capable of doubling both the extraction yield and caffeine concentration, compared with non-soundblasted samples. The team sent samples of the coffee off to be evaluated on aroma, texture, flavor, and aftertaste. Although the one-minute extraction samples received similar ratings to a 24-hour brew in terms of flavor and aftertaste, they lacked the intensity and dark chocolate aroma of the longer brew. But the three-minute extraction samples scored quite highly in all areas, suggesting that the average cold brew drinker wouldn’t be able to tell the difference.

Would you like to roast your own beans at home? You can use a popcorn popper, but you might get tired of semi-uneven roasts and upgrade to a DIY wobble disk roaster.

Continue reading “Much Faster Cold Brew Through Cavitation”