Split Flap Display Tells Us The Word

March 2, 2022 by Bryan Cockfield 12 Comments

LED and LCD displays are a technological marvel. They’ve brought the price of televisions and monitors down to unheard-of levels since the days of CRTs, but this upside arguably comes with an aesthetic cost. When everything is covered in bland computer screens, the world tends to look a lot more monotonous. Not so several decades ago when there were many sharply contrasting ways of displaying information. One example of this different time comes to us by way of this split-flap display that [Erich] has been recreating.

Split-flap displays work by printing letters or numbers on a series of flaps that are attached to a spindle with a stepper motor. Each step of the motor turns the display by one character. They can be noisy and do require a large amount of maintenance compared to modern displays, but have some advantages as well. [Erich]’s version is built out of new acrylic and MDF, and uses an Arduino as the control board. A 3D printer and CNC machine keep the tolerances tight enough for the display to work smoothly and also enable him to expand the display as needed since each character display is fairly modular.

Right now, [Erich]’s display has 20 characters on two different rows and definitely brings us back to the bygone era where displays of this style would have been prominent in airports and train stations. This display uses a lot of the basics from another split flap display that we featured a few years ago but has some improvements. And, if you’d prefer restorations of old displays rather than modern incarnations, we have you covered there as well.

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This Audio Mixer Is A Eurorack

October 4, 2021 by Jenny List 14 Comments

Music making and DJing have both become arts predominantly pursued in a computer, as the mighty USB interface has subsumed audio, MIDI, and even DJ turntable interface controllers. There was a time though when an indispensable part of any aspiring performer’s equipment would have been an analog mixer, a device for buffering and combining multiple analog audio signals into a single whole. A mixer is still a useful device though, and [Sam Kent] has produced a very nice one that takes the form of a set of Eurorack modules made from PCB material. There are two types of modules, the main channel module which you can think of as the master module, and a series of isolator modules that handle the individual inputs.

Mixer preferences are as individual as each user, so for example where we’d expect sliders he’s used rotary potentiometers, and for us placing the master channel on the left-hand side is unfamiliar. But that’s the beauty of a modular design, there’s nothing to stop anyone building one of these to simply configure it as they wish. We notice that for a mixer described as for DJs there’s no RIAA preamp for the turntable fans, but it’s not impossible to fix with an off-board preamp. Otherwise, we like it and have a sudden hankering for it to be 1992 again with a pair of Technics SL1200s and a room full of people.

Designing a mixer, even a simple one, isn’t easy. Our own [Lewin Day] wrote a retrospective of his experiences with one.

Emulating A Power Grid

June 26, 2021 by Bryan Cockfield 23 Comments

The electric power grid, as it exists today, was designed about a century ago to accommodate large, dispersed power plants owned and controlled by the utilities themselves. At the time this seemed like a great idea, but as technology and society have progressed the power grid remains stubbornly rooted in this past. Efforts to modify it to accommodate solar and wind farms, electric cars, and other modern technology need to take great effort to work with the ancient grid setup, often requiring intricate modeling like this visual power grid emulator.

The model is known as LEGOS, the Lite Emulator of Grid Operations, and comes from researchers at RWTH Aachen University. Its goal is to simulate a modern power grid with various generation sources and loads such as homes, offices, or hospitals. It uses a DC circuit to simulate power flow, which is visualized with LEDs. The entire model is modular, so components can be added or subtracted easily to quickly show how the power flow changes as a result of modifications to the grid. There is also a robust automation layer to the entire project, allowing real-time data acquisition of the model to be gathered and analyzed using an open source cloud service called FIWARE.

In order to modernize the grid, simulations like these are needed to make sure there are no knock-on effects of adding or changing such a complex system in ways it was never intended to be changed. Researchers in Europe like the ones developing LEGOS are ahead of the curve, as smart grid technology continues to filter in to all areas of the modern electrical infrastructure. It could also find uses for modeling power grids in areas where changes to the grid can happen rapidly as a result of natural disasters.

Ask Hackaday: Why Make Modular Hardware?

April 27, 2021 by Adam Zeloof 33 Comments

In the movies, everything is modular. Some big gun fell off the spaceship when it crashed? Good thing you can just pick it up and fire it as-is (looking at you, Guardians of the Galaxy 2). Hyperdrive dead? No problem, because in the Star Wars universe you can just drop a new one in and be on your way.

Of course, things just aren’t that simple in the real world. Most systems, be they spaceships or cell phones, are enormously complicated and contain hundreds or thousands of interconnected parts. If the camera in my Samsung phone breaks, I can’t exactly steal the one from my girlfriend’s iPhone. They’re simply not interchangeable because the systems were designed differently. Even if we had the same phone and the cameras were interchangeable, they wouldn’t be easy to swap. We’d have to crack open the phones and carefully perform the switch. Speaking of switches, the Nintendo Switch is a good counterexample here. Joycon break? Just buy a new one and pop it on.

What if more products were like the Nintendo Switch? Is its modularity just the tip of the iceberg?

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Remoticon Video: Intro To Modern Synthesis Using VCV Rack

December 15, 2020 by Dan Maloney 10 Comments

Modular synthesizers, with their profusion of knobs and switches and their seemingly insatiable appetite for patch cables, are wonderful examples of over-complexity — the best kind of complexity, in our view. Play with a synthesizer long enough and you start thinking that any kind of sound is possible, limited only by your imagination in hooking up the various oscillators, filters, and envelope generators. And the aforementioned patch cables, of course, which are always in short supply.

Luckily, though, patch cables and the modules they connect can be virtualized, and in his 2020 Remoticon workshop, Jonathan Foote showed us all the ways VCV Rack can emulate modular synthesizers right on your computer’s desktop. The workshop focused on VCV Rack, where Eurorack-style synthesizer modules are graphically presented in a configurable rack and patched together just like physical synth modules would be.

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Transforming Work Light Is More Than Meets The Eye

December 4, 2020 by Tom Nardi 3 Comments

While it does use the same M12 batteries, this impeccably engineered work light isn’t an official Milwaukee product. It’s the latest creation from [Chris Chimienti], who’s spent enough time in the garage and under the hood to know a thing or two about what makes a good work light. The modular design not only allows you to add or subtract LED panels as needed, but each section is able to rotate independently so it points exactly where you need it.

Magnets embedded in the 3D printed parts mean the light modules not only firmly attach to one another, but can be stuck to whatever you’re working on. Or you could just stack all the lights up vertically and use the rocket-inspired “landing legs” of the base module keep it vertical. Even if the light gets knocked around, the tension provided by rubber bands attached to each fold-out leg means it will resist falling over. In the video after the break [Chris] says the little nosecone on top is just for fun and you don’t have to print it, but we don’t see how you can possibly resist.

The same PCB is used on both ends of the light modules.

Of course, 3D printed parts and magnets don’t self-illuminate. The LED panels and switches are salvaged from cheap lights that [Chris] found locally for a few bucks, and a common voltage regulator board is used to step the 12 volts coming from the Milwaukee battery down to something the LEDs can use. He’s designed a very slick reversible PCB that’s used on either end of each light module to transfer power between them courtesy of semi-circular traces on one side and and matching pogo pins on the other.

As we saw in his recent Dremel 3D20 rebuild, [Chris] isn’t afraid to go all in during the design phase. The amount of CAD work that went into this project is astounding, and serves as fantastic example of the benefits to be had by designing the whole assembly at once rather than doing it piecemeal. It might take longer early on, but the final results really speak for themselves.

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YARH.IO Is The Hackable Pi Portable Of Our Dreams

September 3, 2020 by Tom Nardi 23 Comments

Less than a decade ago, building a completely custom portable computer was more or less out of the question. Sure you could have cobbled something together with a Gumstix board and the dinky NTSC/PAL screen pulled from a portable DVD player, but it wouldn’t exactly have been a daily driver. But now we have cheap high definition LCD panels, desktop 3D printers, and of course, the Raspberry Pi.

We’ve seen these elements combined into bespoke personal computing devices too many times to count now, but very few of them can compare to the incredible YARH.IO. It’s been designed from the ground up for easy assembly and customization; you don’t have to worry about getting custom PCBs made or tracking down some piece of unobtanium hardware. Everything inside of the 3D printed enclosure is an off-the-shelf module, needing little more than the occasional scrap of protoboard to tie them all together.

One glance at the rugged design of the YARH.IO, and it’s clear this device wasn’t meant to live on a shelf. Whether it’s getting tossed around the workbench or thrown into a bag on the way to a hacker con, the militarized design of this portable is ready for action. Using appropriately strong materials such as PETG and ABS, we have no doubt the enclosure will survive whatever the on-the-go hacker can throw at it.

But what’s arguably the best feature of the YARH.IO also happens to be the least obvious: the modular design of the enclosure allows you to remove the lower keyboard section and use it as a battery powered Linux tablet (albeit a rather chunky one). Whether the keyboard is attached or not, you still have access to the Pi’s expansion header thanks to a clever pass-through.

Like with the Mil-Plastic that [Jay Doscher] released recently, we know these 3D printed kits will never be as strong as the real military gear they’re emulating. But let’s be realistic, none of us keyboard warriors will be taking them into an actual battlefield anytime soon. What’s more important is that their modular construction allows them to be easily modified for whatever the user’s needs might be. With as far as the state-of-the-art in DIY bespoke computing as come in the last decade, we can’t wait to see what the future holds.