Rationale 60 - HHKB-like board

[Nlight]

Hi all,

While I love the ergonomic keyboards, like semi-split and vertical staggered, they feel quite unusual and are often bigger. I need a keyboard that is reasonably compact (compared to a full size), with a layout our hands are like 90-95% used to, and which out of the box does not miss any key (maybe one) compared to standard ANSI US. Though it must be able to be adapted internationally, and thus implementing as few layers as possible while remaining easy to remember and get used to.

What I came up with is based on the clever HHKB :


So as you can see, we have three out of the box layers :

• F_fk : F Keys layer that goes onto the number row, so it remains easy to remember
• F_move : Cursor movement layer, with the Vi-like arrows on home row (H : Left, J : Down, K : Up, L : Right), and Home, PgDown, PgUp, End keys just above their arrows counter parts, following the same logic : Home above Left, PgDown above Down, PgUp above Up, End above Right
• F_num : numpad Layer, this one is the less usual out of the three, as the dot is next to 6, 0 next to 1, / is in the same place as when the F_num layer is not active, * next to 9, - next to 7, + next to 4

Note that the four bottom right keys Mute, Vol-, Vol+ and Print Screen are random keys : i had hard time leaving no keys in these places, suggestions are welcome, few of them would probably be used for international additional Keys like [<, >] and [µ, *] for Azerty Fr firmware.

End goal features :

• USB C connector edit : Nope
• Wireless, 2.4Ghz RF with big ass dongle, unless I can come up with a small one, which I doubt edit : Nope, bluetooth, in the end )
• Reprogrammable firmware viastandard Arduino Software python
• RGB ? don't know yet, at least caps lock will have one, anyway there won't be any fancy effects, or any effects at all, it will be functionalNo
• Different pre made firmwares available on a Git Hub repository, for different countries ~maybe
• Double shot PBT DSA caps
• Zealios 62g

Why not Bluetooth ? I may change my mind, but so far, the following problems seem to come up quite often : delays, scripting keys, disconnection problems... so no bluetooth

Why not home-brew firmware tool ? Cause it is a freaking lot of work, and many people get frustrated as it often lack this or that functionality. While it is not barred that I make a QMK like toolbox, the chances are EXTREMELY slim that I do that instead of get in touch with QMK team to see if and how we could make it an option. Anyway at this point, I know too few.

Bluetooth in the end, cause, saw that some arduino -like modules were programmable with python (my favorite language, 12 years using it), but only with bluetooth for wireless versions
So writing my own firmware it will be, as it is in python, it will be a good balance between fun and challenge.

No fancy RGB ? Nope, too much work, plus the board is called rationale, it is intended to be functional first and foremost.

Prototype 0.0

Done
features :

• wired connection
• no leds

goal :

• test layout
• get used to design PCB
• quickly get an operational board to use at work home, my laptop intergrated bluetooth sucks terribly

parts status :

• blank PBT caps : RECEIVED (6 month later, thank you stupid government)
• Switch :: Zealios 65g RGB : RECEIVED, but unused, for now, MX browns used for prototype
• MX stabilizers : RECEIVED
• PCB : ABANDONED Hard Wired
• MCU : Adafruit ItsyBitsy nRF52840 Express
• Case : Prototype-ish sort of done but not really

Adafruit ItsyBitsy nRF52840 Express

[ArchDill]

Not sure if it is just me, but the image is not loading

[Nlight]

Damnit, and now ?

[suicidal_orange]

I can see images

[Nlight]

Cool, thanks 

[Nlight]

Hay all, it's been a WHILE...

Anyway, I finished a rough prototype years ago, and it remained as a prototype. Fixing the broken piece in my 3d printer is not the highest priority expense on my list.
So for closure, here is the prototype (that ended up being a long term prototype)



One can see the fashionable open air MCU mount, totally made this way for cooling purpose... obviously 😅



what would be this keyboard without its stylish bottom. One can admire the superb feet pads
Impressive, right ? 😄

here is the final layout (final result after applying my custom os keyboard layout)



I also made my own "firmware" in python with CircuitPython, which is a blend of MicroPython made by AdaFruit.
Here is the GitHub repo :
https://github.com/Nlight91/keyboard-rationale-60/tree/master

I have not yet made real docs or include any license for now, so here are some precisions :
- the adafruit folders are made by adafruit with MIT license, I shipped it for convenience (these are old versions, but works perfectly)
- the license for the rest, I guess I'll go with MIT too.

I'd like to say, that I love how plugging the MCU to the computer opens it as a drive, where you just have to copy/edit files onto it for it to restart and run its entry point. Plus python is a real pleasure to use.
As for speed I'm not noticing any issue, but I'm not particularly demanding on that front... I almost don't game anymore, at least no FPS.

As for the keycap thoughts after using for quite some time :
if I had my 3d printer working I would have printed my own keycaps for the bottom row, with heavily rounded bottom edges. Indeed, as it stands, the edges are not comfortable at all on the thumbs. To this day this remain the most annoying thing about this keyboard.

I also tried to turn the right space key into a modifier (AltGr) when held down, for better ergonomics, but in the end that made the space register only when released and sometimes led to not be registered, which was super annoying, so... F*** it, roll back to a dedicated space only key.