157 lines
8.5 KiB
Markdown
157 lines
8.5 KiB
Markdown
# urob's zmk-config
|
|
|
|
This is my personal [ZMK firmware](https://github.com/zmkfirmware/zmk/) configuration.
|
|
It is ported from my QMK configuration, which in turn is heavily inspired by Manna Harbour's
|
|
[Miryoku layout](https://github.com/manna-harbour/miryoku).
|
|
|
|
## Key features
|
|
|
|
- clean keymap + unicode setup using helper macros from
|
|
[zmk-nodefree-config](https://github.com/urob/zmk-nodefree-config)
|
|
- keymap and combo setup portable across different physical layouts
|
|
- ["timeless" homerow mods](#timeless-homerow-mods) on the base layer;
|
|
sticky mods on other layers
|
|
- combos replacing the symbol layer
|
|
- sticky shift on right thumb, double-tap (or shift + tap)[^1] activates caps-word
|
|
- shift + space morphs into dot + space + sticky-shift
|
|
- shift + backspace morphs into delete
|
|
- "Greek" layer for mathematical typesetting
|
|
|
|
|
|
|
|
## Timeless homerow mods
|
|
|
|
Homerow mods [are great](https://precondition.github.io/home-row-mods). But they can
|
|
require some finicky timing: In its most naive implementation, in order to produce a "mod",
|
|
they must be held *longer* than `tapping-term-ms`. In order to produce
|
|
a "tap", they must be held *less* than `tapping-term-ms`. This requires very consistent
|
|
typing speeds that, alas, I do not possess. Hence my quest for a "timeless" HRM
|
|
setup.[^2]
|
|
|
|
Here's what I have ended up with: A "timeless" HRM setup with virtually no misfires and
|
|
yet a fluent typing experience with mostly no delays.
|
|
|
|
Let's suppose for a moment we set `tapping-term-ms` to something ridiculously large, say
|
|
5 seconds. This makes the configuration "timeless". But it also creates two
|
|
problems: (1) In order to get a "mod" we now have to hold the HRM keys for
|
|
what feels like eternity. (2) In normal typing, when tapping keys, there can be
|
|
long delays between the press of a key and the time it appears on the screen. Enter my
|
|
two favorite configuration options:
|
|
* To address the first problem, I use ZMK's `balanced` flavor, which produces
|
|
a "hold" if another key is both pressed and released within the tapping-term. Because
|
|
that is exactly what I normally do with HRMs, there is virtually never a need to wait
|
|
past my long tapping term (see below for two exceptions).
|
|
* To address the typing delay, I use ZMK's `global-quick-tap` property, which
|
|
immediately resolves a HRM as "tap" when it is pressed shortly *after* another key
|
|
has been tapped.[^3] This all but completely eliminates the delay when typing.
|
|
|
|
This is almost perfect, but there's still a few rough edges:
|
|
|
|
* When rolling keys, I sometimes unintentionally end up with "nested" key
|
|
sequences: `key 1` down, `key 2` down and up, `key 1` up. Given the `balanced` flavor,
|
|
this would falsely register `key 1` as a mod. To prevent this, I use ZMK's "positional
|
|
hold-tap" feature to force HRMs to always resolve as "tap" when the *next* key is on
|
|
the same side of the keyboard. Problem solved.
|
|
* ... or at least almost. The official ZMK version for positional-hold-taps performs the
|
|
positional check when the next key is *pressed*. This is not ideal, because it
|
|
prevents combining multiple modifiers on the same hand. To fix this, I use a small
|
|
patch that delays the positional-hold-tap decision until the next key's *release* ([PR
|
|
#1423](https://github.com/zmkfirmware/zmk/pull/1423)). With the patch, multiple mods
|
|
can be combined when held, while I still get the benefit from positional-hold-taps
|
|
when keys are tapped.
|
|
* So far, nothing of the configuration depends on the duration of `tapping-term-ms`. In
|
|
practice, there are two reasons why I don't set it to infinity:
|
|
1. Sometimes, in rare circumstances, I want to combine a mod with a alpha-key *on
|
|
the same hand* (e.g., when using the mouse with the other hand). My positional
|
|
hold-tap configuration prevents this *within* the tapping term. By setting the
|
|
tapping term to something large but not crazy large (I use 280ms), I can still
|
|
use same-hand `mod` + `alpha` shortcuts by holding the mod for just a little while
|
|
before tapping the alpha-key.
|
|
2. Sometimes, I want to press a modifier without another key (e.g., on Windows,
|
|
tapping `Win` opens the search menu). Because the `balanced` flavour only
|
|
kicks in when another key is pressed, this also requires waiting past
|
|
`tapping-term-ms`.
|
|
|
|
Here's my configuration (I use a bunch of [helper
|
|
macros](https://github.com/urob/zmk-nodefree-config) to simplify the syntax, but they
|
|
are not necessary):
|
|
|
|
```C++
|
|
/* use helper macros to define left and right hand keys */
|
|
#include "../zmk-nodefree-config/keypos_def/keypos_36keys.h" // keyposition helpers
|
|
#define KEYS_L LT0 LT1 LT2 LT3 LT4 LM0 LM1 LM2 LM3 LM4 LB0 LB1 LB2 LB3 LB4 // left-hand keys
|
|
#define KEYS_R RT0 RT1 RT2 RT3 RT4 RM0 RM1 RM2 RM3 RM4 RB0 RB1 RB2 RB3 RB4 // right-hand keys
|
|
#define THUMBS LH2 LH1 LH0 RH0 RH1 RH2 // thumb keys
|
|
|
|
/* left-hand HRMs */
|
|
ZMK_BEHAVIOR(hml, hold_tap,
|
|
flavor = "balanced";
|
|
tapping-term-ms = <280>;
|
|
quick-tap-ms = <175>; // double tapping same key allows for repeating
|
|
global-quick-tap-ms = <150>; // without PR #1387 use global-quick-tap instead
|
|
bindings = <&kp>, <&kp>;
|
|
hold-trigger-key-positions = <KEYS_R THUMBS>;
|
|
hold-trigger-on-release; // requires PR #1423
|
|
)
|
|
|
|
/* right-hand HRMs */
|
|
ZMK_BEHAVIOR(hmr, hold_tap,
|
|
flavor = "balanced";
|
|
tapping-term-ms = <280>;
|
|
quick-tap-ms = <175>; // double tapping same key allows for repeating
|
|
global-quick-tap-ms = <150>; // without PR #1387 use global-quick-tap instead
|
|
bindings = <&kp>, <&kp>;
|
|
hold-trigger-key-positions = <KEYS_L THUMBS>;
|
|
hold-trigger-on-release; // requires PR #1423
|
|
)
|
|
```
|
|
One last note, the configuration above uses some syntactic sugar introduced in [PR
|
|
#1387](https://github.com/zmkfirmware/zmk/pull/1387), which decouples the
|
|
`quick-tap-ms` timeout from the `global-quick-tap-ms` timeout. Without the PR, one
|
|
can replace `global-quick-tap-ms = <150>` with `global-quick-tap` for a
|
|
similar effect (`global-quick-tap` will use the regular `quick-tap-ms` timeout in this
|
|
case).
|
|
|
|
My personal [ZMK fork](https://github.com/urob/zmk) includes both the
|
|
global-quick-tap-ms PR and the hold-trigger-on-release PR (along with a few other PRs).
|
|
If you are looking for a ZMK-centric introduction to maintaining your own fork with a
|
|
custom selection of PRs, you might find my ["cookbook
|
|
approach"](https://gist.github.com/urob/68a1e206b2356a01b876ed02d3f542c7) helpful.
|
|
|
|
|
|
## A few thoughts on the combo setup
|
|
|
|
The combo layout is guided by two goals: (1) put all combos in easy-to-access locations,
|
|
and (2) make them easy to remember. Specifically:
|
|
|
|
- the top vertical-combo row matches the symbols on a standard numbers row
|
|
(except `+` and `&` being swapped)
|
|
- the bottom vertical-combo row aims for symmetry with the top row
|
|
(subscript `_` aligns with superscript `^`; minus `-` aligns with `+`; division `/`
|
|
aligns with multiplication `*`; logical-or `|` aligns with logical-and `&`)
|
|
- parenthesis, braces, brackets, `!` and `?` all in prime access locations and set up
|
|
symmetrically
|
|
- a numlock shortcut (on `W + P`) for one-handed "data entry" (aka Sudoku 🙂)
|
|
- shortcuts for cut (on `X + D`), copy, and paste on left side (good with right-handed
|
|
mouse use)
|
|
|
|
[^1]: Really what's happening is that `Shift` + my right home-thumb morph into
|
|
caps-word. This gives me two separate ways of activating it: (1) Holding the
|
|
homerow-mod shift on my left index-finger and then pressing my right home-thumb, which
|
|
is my new preferred way. Or, (2) double-tapping the right home-thumb, which also works
|
|
because the first tap yields sticky-shift, activating the mod-morph upon the second
|
|
tap.
|
|
|
|
[^2]: I call it "timeless", because the large tapping-term makes the behavior
|
|
insensitive to the precise timings. One may say that there is still the
|
|
`global-quick-tap` timeout. However, with both a large tapping-term and
|
|
positional-hold-taps, the behavior is *not* actually sensitive to the
|
|
`global-quick-tap` timing: All it does is reduce the delay in typing; i.e., variations
|
|
in typing speed won't affect *what* is being typed but merly *how fast* it appears on
|
|
the screen.
|
|
|
|
[^3]: One potential downside of `global-quick-tap` is that it prevents using modifiers
|
|
*immediately* after another key press. Arguably, this is only problematic for shift,
|
|
which is not a problem for me, because I have a dedicated "sticky shift" on my right
|
|
thumb. If you rely on homerow mods for regular capitalization, you may want to reduce
|
|
the `global-quick-tap` term for just the two shift-mods to about 75-100ms.
|