Custom Keyboards: the Wren

Keyboards, The Bottleneck to the Digital World

Keyboards are the bottleneck into getting things done, communicating, and existing effectively in the modern world. Having a good keyboard that lets you type well and effectively is paramount. The Wren is a stellar keyboard in a crowded market - and it’s open source!

A friend of mine (who agrees that typing well is critical) found an open keyboard project, the wren, which is the most fully-featured split ortho linear keyboard with staggered rows I know. It has more than a full keyboard’s collection of keys, is customizable via QMK, and it even has volume knobs.

The Wren is an impressive kit:

• Is full-featured and over 100% layout
• Has 4 thumb keys
• Is capable of full-speed typing
• Still resembles a QWERTY keyboard layout
• Open source: Cad Files & QMK Firmware

If you’re familiar with QMK, ordering PCB’s, soldering keyboard kits and the like you already know the benefits of a custom keyboards, the wren is simply a the most fully-featured keyboard in its class. If you’d like a deeper dive, I’ll talk about the layout and features, customizing layouts with QMK, finally the path to getting your Wren keyboard.

Design and Features of the Wren

If you look at the Wren keyboard its most striking feature is the layout. The familiar block of keys on most keyboards looks almost entirely different:

• it’s split down the middle (split)
• columns are now staggered (staggered column)
• columns are aligned linearly (ortho linear)

Each of these departures are for ergonomics, or for typing more comfortably. If you want to see someone explore a lot of the ergonomic considerations of typing, this video and the supporting prior videos talk more and in-depth about the topic. It’s a rabbit hole because redesigning your ergonomics never really stops as your body changes and adapts.

The Wren is not the most extreme example of a departure from the standard QWERTY keyboard for the sake of ergonomic design; so far the Svalboard is what I’d consider the most popular extreme departure. Comparatively, the Wren is familiar and conservative.

Compared to a QWERTY layout the Wren is more comfortable to me and after learning and unlearning bad habits from the QWERTY layout (like sliding my middle finger over the “l” column in some cases), I’ve gotten my WPM’s to be comparable. Coding has been trickier, due to the addition of several symbols and clusters of symbols, but with layering provided by QMK I’ve found I can also accomplish this task nearly as effectively as I had been after years of practice coding on QWERTY.

The Wren is also in a class of its own as it boasts 88 keys, where most ergonomic and custom keyboards aim for a “60%” layout. You can get all the alphanumerics, the function keys and a full keypad and nav cluster.

More keys is more options is more power. If smaller is your style, it’s pretty simple to find split ortho linear keyboards in smaller form-factors, and they are usually more popular and easy to find ready-to-build kits.

So far, I’ve left out one of my favorite small details of the wren: the thumb cluster. On each half of the board is a set of 4 keys. These take a little getting used to, but I find the ability to use 4 keys per thumb is a great addition. I’ve mapped mine to be backspace on the left and space on the right, but the possibilities are endless thanks to the next big feature QMK mapping.

QMK and customization

Keyboard kits using programmable ATMEGA micro controllers have limited programmable flash memory, the standard for this firmware is QMK.

• Kit keyboards can use QMK to customize keybindings
• QMK supports features like macros, “tapping”, layers, even mouse movement!
• Programs like Vial and Via allow for more convenient customization
• QMK supports layouts other than QWERTY, such as Colemack, Dvorak, or an entirely custom layout

QMK allows for ultimate customization; while the most common application is to modify layouts to match a board more advanced features like macros, and layers allow small keyboards (e.g. the 40% Rhymestone, with only 40 keys) the ability to access all the keys on a standard keyboard and beyond.

Even standard manufactured keyboards, such as the Keychron brand keyboards, are able to flash QMK.

For kit keyboards it’s essential that you flash the firmware: without it there is no way that the microcontroller will know what the signals across the board mean. For the Wren a standard layout is included in the QMK repository, but it can be customized (which I’ve done).

I like using the layers function to add a “Vim” layer to my keyboard, making it easy to navigate using H J K and L just like in Vim. I’m currently experimenting with nav and developer symbols, but these take some getting used to.

The path to Wren

Getting a Wren means sourcing and fabricating (or ordering) parts. Even compared to other “kit-like” boards, the Wren is not a product that can be bought together.

The Bill of Materials (BOM) is included on the repo here but the steps are roughly as follows

1. Order PCB using the included diagram: the switches sit in this piece and conduct through the leads to the microcontroller
2. Order backplate and front plate
3. Order the microcontroller (consider getting a microcontroller socket)
4. Order Switches of your choice
5. Order remaining hardware (resistors, encoders, diodes, standoffs, etc.)

Waiting to get all the pieces is usually what takes the most time: custom ordering parts is surprisingly fast, but not instantaneous.

Some finer points

If your plates (which hold the switches on the front and protect the pcb on the back) are more than a few millimetres thick, then the screws which interface with your standoffs must compensate. Too thick of a material will interfere with your switches working correctly with the PCB beneath.

Adding a microcontroller socket is a great idea: this is a particularly nasty point to solder into - without a socket it’s rather risky to solder in. If there’s any problem with the microcontroller de soldering the controller is difficult. Doing it without destroying the microcontroller is harder.

I wouldn’t recommend hot-swap switches i.e. via milmax, and other hot-swap solutions don’t work with the board.

A bit much?

The Wren isn’t a starter keyboard. It requires custom hardware all customizable, and it requires all of it to be hand assembled, soldered, and flashed. If you are still using a stock keyboard or a membrane and you haven’t taken the first step in mechanical keyboards, maybe start there: Keychron (which also supports advanced features through QMK) is my personal favorite.

If you’re already into mechanical keyboards and you’re looking to step up your game, the Wren is a fun challenge, but similar split staggered-column ortho-linear borads exist, such as the Moonlander.

You may think that brands like Logitech, Corsair, and Steelseries are good candidates for “safe,” keyboards, but from my experience with these brands the boards aren’t amazing and don’t really offer much beyond the walled gardens they’re trying to erect. QMK allows for your own limitations and your own creativity to be the bounds.