Repetitive strain injuries (RSI) can be a real pain. You’ve got a shiny new laptop, and everything’s going smoothly, but suddenly you can’t use it without agonizing (as in typing-speed reducing) pain caused by years of keyboard bashing or just plain bad posture. All of us hacker types will likely have or will experience this at some point, and luckily there are many potential solutions.
[Zihao Wang] writes to show us kseqi, another chord-like textual input method, with a focus on the input sequences, as opposed to any particular mechanical arrangement of keys. The idea is to make use of two sets of independent inputs, where the sequence of actuation codes for the keystrokes to be emitted into the application.
An example interface would be to arrange two sets of five keys as the input mechanism. One can arrange characters in a matrix. The left key is pressed and held first which selects a column (1 out of 5) then the right key is pressed to select a row, and thus a character. Next, you release in the same order, left, then right, to send the character.
Swapping left and right allows a different set of characters. In this simple scheme, fifty characters can be coded. Check out this web assembly demo for how this operates. Swapping out the physical inputs for a pair of joysticks is another option, which may be better for some folks with specific physical difficulties, or maybe because it just looks fun. As [Zihao] mentions in the write-up, the sequence order can be changed to code for other character sets, so this simple scheme can handle many more character codings than this simple example. All you have to do is remember them. Interested parties may want also wish to dig into the kseqi Rust crate for information.
The lily58, which is a 58-key split with dual OLED footprints, was just a starting point for this build. For tablet mode, where the keyboard is attached to the back of a tablet with hook-and-loop tape, [_GEIST_] created custom plates that double the thumb keys on the back.
We love that there is a PSP thumbstick for mousing on one layer and inputting keystrokes on other layer. But we can’t decide which is our favorite part: the fact that [_GEIST_] threaded it through the bottom of a Kailh Choc switch, or the fact that there’s a Pimoroni Haptic Buzz with a different wave form for each layer. [_GEIST_] also added an acrylic middle plate layer to support quick-change magnetic tenting legs.
Somewhere between the onset of annoying hand pain and the feeling of worn-out, mushy switches, [sinbeard]’s keyboard dissatisfaction came to a head. He decided it was time to slip into something bit more ergonomic and settled on building an Iris — a small split keeb with an ortholinear (non-staggered) key arrangement.
The Iris is open source and uses an on-board controller, so you can have the boards fabbed and do a lot of SMD soldering, or get a pair of PCBs with all of that already done. [sinbeard] went the latter route with this build, but there’s still plenty of soldering and assembly to do before it’s time to start clackin’, such as the TRRS jacks, the rotary encoders, and of course, all the switches. It’s a great way for people to get their feet wet when it comes to building keyboards.
Everything went according to plan until it was time to flash the firmware and it didn’t respond. It’s worth noting that both of the Iris PCBs are the same, and both are fully populated. This is both good and bad.
It’s bad you have two on-board microcontrollers and their crystals to worry about instead of one. It’s good because there’s a USB port on both sides so you can plug in whichever side you prefer, and this comes in mighty handy if you have to troubleshoot.
When one side’s underglow lit up but not the other, [sinbeard] busted out the ISP programmer. But in the end, he found the problem — a dent in the crystal — by staring at the board. A cheap replacement part and a little hot air rework action was all it took to get this Iris to bloom.