Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Typewriter Orchestra

January 31, 2024 by 2 Comments

Have you ever wished you had more control over what goes into a kit keyboard build? Like, a whole lot more control? Well, that’s the idea behind the Akruvia 12×4 Playground by [iketsj].

Image by [iketsj] via YouTube

This is a 48-key ortholinear keyboard, but other than that, it’s a complete blank slate. The kit includes the PCB, diodes, RGB LEDs, and Kailh Choc V1 hot swap sockets, which is really the only choice you don’t have in the matter.

All the rest is up to you, thanks to a generous prototyping area that wraps around three sides of the keys. Bring your own microcontroller and anything else that sounds useful, like displays, rotary encoders, gesture sensors, pointing devices, you name it.
You could even magnetically link a macro pad to one side, as [iketsj] teases in the intro video. [iketsj] has made the kit available through links on their website, and you’ll find a product guide there as well.

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The Cockpit Voice Recorder Controversy

January 31, 2024 by 75 Comments

Every time there’s a plane crash or other aviation safety incident, we often hear talk of the famous “black box”. Of course, anyone these days will tell you that they’re not black, but orange, for visibility’s sake. Plus, there’s often not one black box, but two! There’s a Flight Data Recorder (FDR), charged with recording aircraft telemetry, and a Cockpit Voice Recorder (CVR), designed to record what’s going on in the cabin.

It sounds straightforward enough, but the cockpit voice recorder has actually become the subject of some controversy in recent times. Let’s talk about the basics of these important safety devices, and why they’re the subject of some debate at the present time.

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Getting Started With USB-C And Common Pitfalls With Charging And Data Transfer

January 28, 2024 by 28 Comments

USB-C is one of those things that generally everyone seems to agree on that it is a ‘good thing’, but is it really? In this first part of a series on USB-C, [Andreas Spiess] takes us through the theory of USB-C and USB Power Delivery (PD), as well as data transfer with USB-C cables. Even ignoring the obvious conclusion that with USB-C USB should now actually be called the ‘Universal Parallel Bus’ on account of its two pairs of differential data lines, there’s quite a bit of theory and associated implementation details involved.

The Raspberry Pi 4B's wrong USB-C CC-pin configuration is a good teaching example.
The Raspberry Pi 4B’s wrong USB-C CC-pin configuration is a good teaching example.

Starting with the USB 2.0 ‘legacy mode’ and the very boring and predictable 5 V power delivery in this mode, [Andreas] shows why you may not get any power delivered to a device with USB-C connector. Most likely the Downstream Facing Peripheral (DFP, AKA not the host) lacks the required resistors on the CC (Configuration Channel) pins, which are both what the other USB-C end uses to determine the connector orientation, as well as what type of device is connected.

This is where early Raspberry Pi 4B users for example saw themselves caught by surprise when their boards didn’t power up except with some USB cables.

The saga continues through [Andreas]’s collection of USB-C cables, as he shows that many of them lack the TX/RX pairs, and that’s before trying to figure out which cables have the e-marker chip to allow for higher voltages and currents.

On the whole we’re still excited about what USB-C brings to the table, but the sheer complexity and number of variables make that there are a myriad of ways in which something cannot work as expected. Ergo Caveat Emptor.

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Hotshot 3D Printed Hovercraft Is Devastatingly Fast

January 27, 2024 by 8 Comments

These days, it’s pretty cheap and easy to build your own little RC hovercraft. [ValRC] demonstrates just that with a hovercraft build that is surprisingly nimble, and fast to boot.

The build started with a design [ValRC] found online. It was simple enough to print and assemble, needing only a pair of a brushless motors, a speed controller, a receiver, and a servo to run the show. The design uses a plastic bag as a skirt, assembled around a 3D printed frame. That proved to be the hardest part of the build, as hot glue didn’t want to play nice with the thin garbage bag.

Even despite the challenges, once assembled, the hovercraft performed well. It readily slid around on a cushion of air, drifting across asphalt with abandon. Upgrades included a better rudder and a skirt made of thicker and more resilient plastic.  The final craft looked mesmerizing as it glided over the smooth concrete of a parking garage with ease.

A hovercraft is, honestly, one of the cooler printable projects for beginners. All you need is a simple design, some powerful motors, and you’re good to go.

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Nanotechnology In Ancient Rome? There Is Evidence

January 26, 2024 by 47 Comments

Anything related to nanotechnology feels fairly modern, doesn’t it? Although Richard Feynman planted the seeds of the idea in 1959, the word itself didn’t really get formed until the 70s or 80s, depending on who you ask. But there is evidence that nanotechnology could have existed as far back as the 4th century in ancient Rome.

That evidence lies in this, the Lycurgus cup. It’s an example of dichroic glass — that is, glass that takes on a different color depending on the light source. In this case, the opaque green of front lighting gives way to glowing red when light is shining through it. The mythology that explains the scene varies a bit, but the main character is King Lycurgus, king of Edoni in Thrace.

So how does it work? The glass contains extremely small quantities of colloidal gold and silver — nanoparticles of gold to produce the red, and silver particles to make the milky green. The composition of the Lycurgus cup was puzzling until the 1990s, when small pieces of the same type of glass were discovered in ancient Roman ruins and analyzed. The particles in the Lycurgus cup are thought to be the size of one thousandth of a grain of table salt — substantial enough to reflect light without blocking it.

The question is, how much did the Romans know about what they were doing? Did they really have the means to grind these particles into dust and purposely infuse them, or could this dichroic glass have been produced purely by accident? Be sure to check out the videos after the break that discuss this fascinating piece of drinkware.

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Displays We Love Hacking: Parallel RGB

January 25, 2024 by 8 Comments

You might have seen old display panels, from 3″ to 10″, with 40-pin FFC connectors where every pin seems to be used for some data signal. We call these displays parallel RGB, or TTL RGB, or DPI, and you can find them in higher-power MCU, Raspberry Pi, and other Linux SBC projects. You deserve to know what to do with those – let’s take a look.

The idea is simple – this interface requires you to constantly send a stream of pixels to the display, and you need to send those pixels through a parallel bus. You can send up to 8 bits per color channel per pixel, which makes for 24 bits, and the 24-bit mode is indeed the standard, but in practice, many parallel RGB implementations don’t bother with more than 5-6 bits of color – two common kinds of parallel RGB links are RGB565 and RGB666. The parallel RGB interface is a very straightforward approach to sending pixels to your display, and in many cases, you can also convert parallel RGB to LVDS or VGA interfaces relatively easily!

If you’re new to it, the easiest way you can drive a parallel RGB display is from a Raspberry Pi, where the parallel RGB interface is known as DPI. This is how 800 x 480 display Pi HATs like the Pimoroni HyperPixel work – they use up almost all of the GPIOs on your Pi, but you get a reasonably high-resolution display with a low power footprint, and you don’t need any intermediate ICs either. FPGAs and some higher-grade MCUs also often have parallel RGB output capability, and surely, someone could even use the RP2040 PIO as well!

Throughout the last decade, parallel RGB has been used less and less, but you will still encounter it – maybe you’re working with an old game console like the PSP and would like to put new guts into it, maybe you’re playing with some tasty display that uses parallel RGB, or maybe you’d like to convert parallel RGB into something else while treating it with respect! Let’s go through what makes parallel RGB tick, what tools you have got to work with it, and a few tips and tricks. Continue reading “Displays We Love Hacking: Parallel RGB” →

DB Cooper Case Could Close Soon Thanks To Particle Evidence

January 23, 2024 by 47 Comments

It’s one of the strangest unsolved cases, and even though the FBI closed their investigation back in 2016, this may be the year it cracks wide open. On November 24, 1971, Dan Cooper, who would become known as DB Cooper due to a mistake by the media, skyjacked a Boeing 727 — Northwest Orient Airlines Flight 305 — headed from Portland to Seattle.

During the flight, mild-mannered Cooper coolly notified a flight attendant sitting behind him via neatly-handwritten note that he had a bomb in his briefcase. His demands were a sum of $200,000 (about $1.5 M today) and four parachutes once they got to Seattle. Upon landing, Cooper released the passengers and demanded that the plane be refueled and pointed toward Mexico City with him and most of the original crew aboard. But around 30 minutes into the flight, Cooper opened the plane’s aft staircase and vanished, parachuting into the night sky.

In the investigation that followed, the FBI recovered Cooper’s clip-on tie, tie clip, and two of the four parachutes. While it’s unclear why Cooper would have left the tie behind, it has become the biggest source of evidence for identifying him. New evidence shows that a previously unidentified particle on the tie has been identified as “titanium smeared with stainless steel”.

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