Redox Redux: Split Keeb Gets A Num Pad

What’s the worst thing about split keyboards? If they have one general fault, it’s that almost none of them have a number pad. If you can fly on that thing, but struggle with using the top row numbers, you will miss the num pad terribly, trust us. So what’s the answer? Design your own keyboard, of course. [ToasterFuel] had enough bread lying around to cook up a little experiment for his first keyboard build, and we think the result is well done, which is kind of rare for first keebs.

This design is based on the Redox, itself a remix of the ErgoDox that aims to address the common complaints about the latter — it’s just too darn big, and the thumb clusters are almost unusable. We love how customized this layout is, with its sprinkling of F keys and Escape in the Caps Lock position. Under those keycaps you’ll find 100% Cherry MX greens, so [ToasterFuel] must have pretty strong fingers to pound those super clackers.

Everything else under the hood is pretty standard, with a pair of Arduino Pro Micros running the show. [ToasterFuel] had to wire up the whole thing by hand because of the num pad, and we’re impressed that he built this entire project in just three weeks. And that includes writing his own firmware!

Already found or built a split you love, but still miss the num pad? Why not build one to match your keyboard?

A Self-Driving Bicycle Is Something To Marvel At

One of the most annoying things about bicycles is that they don’t stay up on their own, especially when they’re stationary. That’s why they come with stands, after all. That said, if you had plenty of advanced electronic and mechanical equipment fitted to one, you could do something about that, and that’s just what [稚晖君] did.

The video of the project comes without subtitles or any translation, but the gist of it is this. A reaction wheel is fitted to the seat tube, along with a motor which can turn the handlebars via a linkage attached to the head stem. There’s also a motor to drive the bicycle forward via a friction drive to the rear wheel. Combine these with an inertial measurement unit and suitable control system, and you have a bike that can balance while standing perfectly still.

The performance of the system is impressive, and is even able to hold the bike perfectly upright while balanced on a fence rail. Thanks to an onboard camera and LIDAR system, the bike can also drive itself around with no rider on board, which is quite a spooky image. Find a way to do the same while hiding the extra mechanics and you’d have one hell of a Halloween display.

Similar projects have been attempted in the past; we featured a self-balancing bike built as a university project back in the distant past of 2012. Video after the break.

Continue reading “A Self-Driving Bicycle Is Something To Marvel At”

An Explanation Of A Classic Semiconductor Riddle

Back in 1996, Bob Pease posed an experiment in an April Fools column. “Take an ordinary NPN transistor, ground the base, pull the emitter up to 12 V with a 1 KΩ resistor and measure the collector voltage referenced to ground.” Do the experiment, and you might be surprised to find a small negative voltage present on the collector. [Filip Piorski] has always loved the riddle, and has explained how it works in a Youtube video.

The key to the trick is the breakdown voltage of the transistor; normally somewhere around 7-8 volts for a typical small NPN transistor. At this point, where the base-emitter junction enters the breakdown regime, it begins to emit light. This light actually travels through the silicon lattice, where it reaches the base-collector junction, which acts like a photodiode under the right conditions. This generates the negative voltage seen at the collector under these conditions.

[Filip] goes on to try the experiment with a TO-3 transistor with the top cut off so he could visualise the effect in action. His photos, taken in a dark room, show tiny flecks of light appearing at spots on the silicon die. If you’ve got more insight on the effect in action, drop a comment below.

It might seem like a simple curiosity, however silicon junctions and their light emissions are an area of active research in semiconductor physics. Video after the break.

Continue reading “An Explanation Of A Classic Semiconductor Riddle”

Survey Of Simple Logic Simulators

A few months ago, a tweet by [Ken Shirriff] asking about simple digital simulators caught my attention. The topic came up again in May when a repair video by [CuriousMarc] featured one such simulator called Logisim-evolution. It made me want to take a fresh look on what’s out there and which features set the different simulators apart.

So today, let’s take a quick survey of a few such simulators that I found. I’m focusing on plain logic simulators, analyzing ones and zeros using Boolean logic. They are not doing SPICE-like analog analysis of transistor logic gates, but they’re still quite handy for proofing out designs.

Continue reading “Survey Of Simple Logic Simulators”

Final Weekend For Display Challenge Of The Hackaday Prize

This is the final weekend to enter your display-related project in the 2021 Hackaday Prize. The good news is, pretty much anything that has a display on it fits the bill here.

The goal of the “Rethink Displays” challenge is to envision interesting ways to visualize data. How many times an hour do you reach for an unlock a smartphone just to get a small bit of data — current temperature, upcoming appointment, the next street to turn on, or how much time is left on your soufflé. There must be another way!

The newspaper is an eInk display that hides in plain sight among non-dynamic framed artwork.

That’s where you come in! Show off us a clever way to convey meaning by choosing a display that makes sense for the type of data and power budget available. Maybe it’s an ePaper display that camouflages itself as wall art, a set of analog meters for the current weather, or a way to upcycle old displays to live on after their portable lives have ended.

This doesn’t need to be a final product. Ten entries will be selected to receive a $500 prize and move on to the final round at the end of October. So if you spend this weekend pulling together a proof of concept, and do a superb job of telling the story of what you’re building, you’ll be firmly in the running! Finalists will have plenty of time to work on completing the designs.

Have a great idea but no time to work on it? Let people know it’s up for grabs by sharing the concept below.

Automatic Chessboard Lets Online Players Move The Pieces

Playing chess online is all well and good, and opens up a whole world of competitors that would otherwise be unavailable in one’s local area. But there’s something to be said for playing over the board, which comes up often enough for many players that they refer to it with the acronym OTB. [Carlos] built an automatic chessboard by the name of Phantom, intending to bridge the disparate worlds of chess, from cyberspace to meatspace.

The Phantom board in action.

The basic idea is a chessboard that a player can use in the typical way, moving the pieces on the board as normal. The opposing pieces are then moved automatically to reflect an opposing player’s moves as received from an online chess server.

The board outwardly appears normal, with little to suggest anything is amiss. Only the metallic gleam at the base of each piece gives the game away. Pieces are moved by a SCARA arm hidden inside the board, which uses a magnet to drag them around from position to position. It’s quite something to watch the pieces glide around as if by magic, even more so when one is dragged off the board in a combat situation.

As for the control system, an Arduino Nano 33 IoT handles online connectivity to fetch game data from the Lichess chess server, while an ESP32 is responsible for all the motors, and a regular Arduino Nano scans a matrix of Hall effect sensors responsible for locating pieces on the board.

The system allows for seamless play, detecting when pieces are moved by the player via the Hall effect sensors, and reporting back to the chess server online. Similarly, when the game state is updated, the SCARA arm steps in to move the relevant pieces reflecting the moves of the distant player.

It’s a fun project, and one that will surely light up the many chessheads in the Hackaday community. We’ve seen other automated chess builds before too, like Trap Chess, in which pieces can suddenly fall from the board at any time. Video after the break.

Continue reading “Automatic Chessboard Lets Online Players Move The Pieces”

Injection-Molded Glass Breakthrough Shatters Ceiling Of Work Methods

Glass is one of humanity’s oldest materials, and it is still used widely for everything from drinking vessels and packaging to optics and communications. Unfortunately, the methods for working with glass are stuck in the past. Most methods require a lot of high heat in the range of 1500 °C to 2000 °C, and they’re all limited in the complexity of shapes that can be made.

As far as making shapes goes, glass can be blown and molten glass pressed into molds. Glass can also be ground, etched, or cast in a kiln. Glass would be fantastic for many applications if it weren’t for the whole limited geometry thing. Because of the limitations of forming glass, some optic lenses are made with polymers, even though glass has better optical characteristics.

Ideally, glass could be injection molded like plastic. The benefits of this would be twofold: more intricate shapes would be possible, and they would have a much faster manufacturing time. Well, the wait is over. Researchers at Germany’s University of Freiburg have figured out a way to apply injection molding to glass. And it’s not just any glass — they’ve made highly-quality, transparent fused quartz glass, and they did it at lower temperatures than traditional methods. The team used x-ray diffraction to verify that the glass is amorphous and free of crystals, and were able to confirm its optical transparency three ways — light microscopy, UV-visible, and infrared measurements. All it revealed was a tiny bit of dust, which is to be expected outside of a clean room.

Continue reading “Injection-Molded Glass Breakthrough Shatters Ceiling Of Work Methods”