ZMK Config

Personal ZMK firmware configuration for split ergonomic keyboards with full Swedish locale support.

Supported Keyboards

Keyboard	Keys	Controller	Display	Shield Source
Brain	40	nice!nano	nice!view	Custom (in-repo)
Urchin	34	nice!nano	nice!view	Custom (in-repo)
Cradio / Sweep	34	—	—	Upstream ZMK

All three are split keyboards using a Pro Micro-compatible footprint. Brain and Urchin include custom shield definitions under config/boards/shields/. Urchin and Cradio share the same 34-key keymap.

Features

• Swedish key support — Custom macros in config/swe_keys.h for Å, Ä, Ö and all Swedish-layout symbols (shifted and AltGr variants)
• Homerow mods — Two hold-tap flavors (hm at 200 ms, hs at 300 ms), both tap-preferred, with quick-tap for key repeat
• Combos — Esc, Tab, and modifier combos on both keymaps; Å, Ä, Ö accessible via combos on the 34-key base layers
• Tri-layer — Holding SYMBOLS_SWE + FUNC activates the SETTINGS layer
• Gaming layer — Dedicated layer with game-friendly bindings and Swedish characters on both keymaps
• Multiple base layers — The 34-key keymap includes switchable Default (Colemak-ish), QWERTY, and Gaming base layers

Layers

Brain (40-key)

Layer	Description
DEFAULT	Alpha layout with Ö, Å, Ä and dedicated shift/GUI keys
GAMING	Number row on left hand, quick access to symbol/function layers
SYMBOLS_SWE	Swedish symbol macros — brackets, quotes, pipes, etc.
FUNC	F1–F12, navigation, media controls, Caps Lock
NUMBER	Full digit row, arithmetic operators
SETTINGS	Bluetooth profiles, BLE/USB output, bootloader, layer toggles

Cradio / Urchin (34-key)

Layer	Description
DEFAULT	Colemak-style alpha with full homerow mods (GUI, Alt, Shift, Ctrl)
QWERTY	Traditional QWERTY alternative
GAMING	Game-optimized left hand with Tab, Shift, Ctrl
SYMBOLS_SWE	Swedish symbol macros + Å, Ä, Ö
FUNC	F1–F12, navigation, media controls, Caps Lock
NUMBER	Digits with homerow-style modifiers
SETTINGS	Bluetooth, output switching, bootloader, base layer toggles

Brain Layout

Building

Firmware is built via GitHub Actions. The active build targets in build.yaml are:

brain_left  + nice_view_adapter nice_view  (nice_nano)
brain_right + nice_view_adapter nice_view  (nice_nano)
settings_reset                             (nice_nano)

Urchin and Cradio targets exist in build.yaml but are commented out. Uncomment them to build those variants.

The repo tracks ZMK main via config/west.yml.

Symbol Mnemonics

Reference for which key produces which symbol on the symbol layers:

Symbol	Name	Letter	Mnemonic
!	Exclamation mark	F	FUCK!!
#	Hash	X	X≈#
$	Dollar	D	Dollar
%	Percent	Z	Z≈%
^	Caret	C	Caret
&	And	R	R≈&
*	Asterisk, star	S	Star
_	Underscore	U	Underscore
-	Hyphen, minus, or dash	M	Minus
+	Plus	P	Plus
=	Equal	E	Equal
\	Backslash	B	Backslash
|	Vertical bar, pipe, or or	I	I≈|
'	Apostrophe, Single quote	A	Apostrophe
"	Quotation mark, Double quote	Q	Quotation mark
?	Question mark	?	Why?, y?
~	Tilde	N	None
@	At	W	None
(	Open or Left parenthesis	J	None
)	Close or Right parenthesis	L	None
{	Open or Left brace	K	None
}	Close or Right brace	H	None
[	Open or Left bracket	G	None
]	Close or Right bracket	V	None
<	Less than	,	None
>	Greater than	:	None
;	Semicolon	baselayer	None
:	Colon	baselayer	None
,	Comma	baselayer	None
.	Period, dot, or full stop	baselayer	None
/	Slash or forward slash	baselayer	None

TODO

• Mnemonics in markdown instead of the picture
• Finish layout for brain
• Caps word more info
• Caps number more info