An exploded view render of a red 3D printed case with a green PCB is inside with visible USB-A connectors with a mouse and keyboard graphic above each and "A" and "B" labels above USB-C connectors on the other side.

Building A Better Keyboard And Mouse Switch

Switching inputs between desktops seems like something that should be simple but can prove to be a pain in reality. [Hrvoje Cavrak] decided to take matters into his own hands and build a better keyboard and mouse switch.

DeskHop is built from two Raspberry Pi Pico boards connected via UART and separated by an Analog Devices ADuM1201 dual-channel digital isolator. Through the magic of Pico-PIO-USB these RP2040s can be both host and device. To keep things simple, the PCB is single-sided, and the BOM only has five distinct components.

Once hooked up to your Windows, Mac, or Linux device, your mouse pointer “magically” goes from one screen to the other when dragged across the screen edge. Keyboard LEDs can be reprogrammed to indicate which device is active, and the real beauty of the device is that since it’s a hardware solution, you don’t have to install any software on a computer you might not have admin access to.

If you want to see some more ideas for keyboard and mouse switching, check out this Pi KVM with ATX signaling, this USB triplexer, or this Pi KVM on a PCIe card.

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

Keebin’ With Kristina: The One With All The LEGO

It seems like mechanical keyboard enthusiasts are more spoiled for choice with each passing day. But as broad as the open source pool has become, there’s still no perfect keyboard for everyone. So, as people innovate toward their own personal endgame peripherals and make them open source, the pool just grows and grows.

Image by [Bo Yao] via Hackaday.IO
This beautiful addition to the glittering pool — [Bo Yao]’s Carpenter Tau keyboard — is meant to provide an elegant option at a particular intersection where no keyboards currently exist — the holy trinity of open source, programmable, and tri-mode connectivity: wired, Bluetooth, and 2.4 GHz.

Come for the lovely wooden everything, and stay for the in-depth logs as [Bo Yao] introduces the project and its roots, reviews various options for the controller, discusses the manufacture of the wooden parts, and creates the schematic for the 61-key version. Don’t want to build one yourself? It’ll be on Crowd Supply soon enough.

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Mind Control… No, Not Like That

[Vintage Geek] found an interesting device from 1996 called “MindDrive” which claims you can control your computer with your brain. Oddly, though, it doesn’t connect to your head. Instead, it has a little finger sensor that looks like a pulse-ox sensor. Did it work? The video below will show you what it can and can’t do.

The company claims the device is the result of seven years of research. We suspect it is little more than a galvanometer, like a kid’s toy lie detector. There is a gold sensor and a Velcro strap. It is hard to imagine that it was feasible that “thinking left” would cause a change in your finger that the device can interpret.

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Nyan Keys: Because Your Keyboard Is Painfully Slow

You probably don’t notice keyboard latency when typing or doing mundane tasks, but if you start gaming, that’s also when you might start complaining. Every millisecond counts in that arena. Think your keyboard is fast? Think again. Because unfortunately, no matter what you’ve got in there, that key matrix is slowing you down. What you need is an FPGA-based keyboard with an overkill MCU. You need Nyan Keys.

[Portland.HODL] set out to make the lowest-latency mechanical keyboard possible that would accept any Cherry-compatible switches, and boy howdy, is this thing fast.

Coupled with the STM32F723VET6 MCU is USB 2.0 HS, which has an 8000Hz polling rate. At worst, key latency measures 30μS, which blows the 1mS average out of the water.

Because it uses a Lattice Semi iCE40HX 4k FPGA, each key switch can connect to its own I/O pin, which also eliminates the need for diodes.

It also means that each key switch can have its own “core” — an 8-bit timer that is always counting up to 255. The key can only change its state when the timer reads 255. This acts as a rather clever debounce mechanism.

If all that’s not enough, [Portland.HODL] built an operating system called NyanOS written in C to avoid any performance-reducing overhead. Oh, and it has an opt-in Bitcoin miner.

We’ve seen a lot of keyboards, the fast ones are fast because of the input side — they are chording keyboards that take combinations to type, rather than using one key (or so) per character. The Characorder is so fast that it was banned from competition.

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

Keebin’ With Kristina: The One With The Biblically-Accurate Keyboard

Well, it was bound to happen at some point. [sporewoh]’s bunchiez40 keyboard for ants is made of mouse switches, which of course begs for a mouse made of keyboard switches.

Image by [sporewoh] via GitHub
[sporewoh]’s keyboards have been steadily shrinking, and they built this in order to get the smallest possible form factor for the number of keys. Surprisingly, since the mouse switches have an actuation force similar to some heavier MX-style switches (~70 g), [sporewoh] is able to squeeze 85 WPM out of it, albeit with some argument from the wrists.

If you want to build a bunchiez40, everything is available on GitHub, including the CAD files for that lovely anodized aluminium case. The typing video is coming soon, and I’m taking bets on whether it’s as quiet as a mouse, as one redditor joked.

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A Toe-Tappin’ Set Of Morse Code Pedals

What’s the worst thing about traditional Morse keyers? If you ask us, it’s the fact that you have to learn how to do two distinct things with one hand, and switch between them quite quickly and often.

This set of Morse code foot pedals is meant for those who are unable to use traditional methods of keying. It uses a retrofitted wireless keyboard to read Z and X as dit and dah, respectively, and convert the Morse code into text.

[Tevendale_Engineering] started by getting the controller out of the keyboard and figuring out which combination of pads sends Z and X. Then they wired those up with copper tape. The pedals themselves are made from 1/2″-thick wood, foam core board, and Nerf bullets to provide springiness.

There’s no solder here; it’s all copper tape and alligator clip test leads. So if this isn’t your hack for the day, we don’t know what is.

Not so great at Morse code? Here’s a clock that will train you on the numbers, at least.

Freshening Up Google’s USB-C PD Sniffer

USB-C Power Delivery has definitely made the big mess of wires a bit smaller but not all cables are created equal — some of them can handle upwards of 100 W while the cheapest can handle only 10. To accommodate this, USB-C cables need to actively tell both ends what their capabilities are, which turns an otherwise passive device into a hidden chip in a passive looking cable.

[Greg Davill] has decided to unravel the mystery of why your laptop isn’t charging by creating a USB-PD sniffer. Based on Google’s Twinkie sniffer, the FreshTwinkie makes the design more accessible by reducing the number of layers in the PCB and replacing the BGA variant of the STM32 for a more DIY-friendly QFN version. Interestingly, this isn’t the first time we’ve seen somebody try and simplify the Twinkie; back in 2021, the Twonkie from from [dojoe] hit a number of similar notes.

USB-C Power Delivery is just one of many protocols spoken over the CC pins, and the FreshTwinkie might be able to detect when some of those are enabled and why or why not. With future development, it could potentially provide useful information as to why a Thunderbolt 4 or tunneled PCIe device isn’t working correctly.