zmk/zmk-nodefree-config/README.md

zmk-nodefree-config

ZMK lets user customize their keyboard layout by providing a Devicetree file (.keymap). The specific syntax requirements of the Devicetree file format can, however, make this process a bit daunting for new users.

This repository provides simple convenience macros that simplify the configuration for many common use cases. It results in a "node-free" user configuration with a more streamlined syntax. Check out example.keymap to see it in action.

Overview

The following convenience macros are provided:

1. ZMK_BEHAVIOR can be used to create new behaviors such as hold-taps, tap-dances or ZMK macros [doc]
2. ZMK_LAYER adds new layers to your keymap [doc]
3. ZMK_COMBO defines new combos [doc]
4. ZMK_CONDITIONAL_LAYERS sets up "tri-layer" conditions [doc]
5. ZMK_UNICODE_SINGLE and ZMK_UNICODE_PAIR create unicode characters [doc]
6. optional international_chars source files define a number of international character such as ä/Ä or δ/Δ that can be added to the keymap [doc]
7. optional keypos_def source files define human-readable key position shortcuts for some popular keyboards that simplify the configuration of combos and positional hold-taps [doc]

Quickstart

1. Copy this repository into the root folder of your private zmk-config repository. The folder structure should look as follows:

    zmk-config
     ├── config
     │    ├── your.keyboard.conf
     │    ├── your_keyboard.keymap
     │    └── ...
     ├── zmk-nodefree-config
     │    ├── helper.h
     │    ├── ...
   

2. Source helper.h near the top of your .keymap file:

   #include "../zmk-nodefree-config/helper.h"
   

3. Customize your keyboard's .keymap file. See example.keymap or my personal zmk-config for a complete configuration, and read the documentation below for details.

Configuration details

ZMK_BEHAVIOR

ZMK_BEHAVIOR can be used to create any of the following ZMK behaviors: caps-word, hold-tap, key-repeat, macro, mod-morph, sticky-key or tap-dance

Syntax: ZMK_BEHAVIOR(name, type, specification)

• name: a unique string chosen by the user (e.g., my_behavior). The new behavior can be added to the keymap using &name (e.g., &my_behavior)
• type: the behavior to be created. It must be one of the following: caps_word, hold_tap, key_repeat, macro, mod_morph, sticky_key or tap_dance. Note that two-word types are separated by underscores (_).
• specification: the custom behavior code. It should contain the body of the corresponding ZMK behavior configuration without the label, #binding-cells and compatible properties and without the surrounding node-specification.

Example 1: Creating a custom "homerow mod" tap-hold behavior

ZMK_BEHAVIOR(hrm, hold_tap,
    flavor = "balanced";
    tapping-term-ms = <280>;
    quick-tap-ms = <125>;
    global-quick-tap;
    bindings = <&kp>, <&kp>;
)

The new behavior can be added to the keymap-layout using &hrm (e.g., &hrm LSHIFT T creates a key that yields T on tap and LSHIFT on hold, using the custom configuration above).

Example 2: Creating a custom tap-dance key

ZMK_BEHAVIOR(ss_cw, tap_dance,
    tapping-term-ms = <200>;
    bindings = <&sk LSHFT>, <&caps_word>;
)

The new behavior can be added to the keymap-layout using &ss_cw. The key yields sticky-shift on tap and caps-word on double tap;

Example 3: Creating a custom "win-sleep" macro

ZMK_BEHAVIOR(win_sleep, macro,
    wait-ms = <100>;
    tap-ms = <5>;
    bindings = <&kp LG(X) &kp U &kp S>;
)

This creates a "Windows sleep key" that can be added to the keymap-layout using &win_sleep.

ZMK_LAYER

ZMK_LAYER adds new keymap layers to the configuration.

Syntax: ZMK_LAYER(name, layout)

• name: a unique identifier string chosen by the user (usually this isn't referenced elsewhere)
• layout: the layout specification using the same syntax as the bindings property of the ZMK keymap configuration

Multiple layers can be added with repeated calls of ZMK_LAYER. They will be ordered in the same order in which they are created, with the first-specified layer being the "lowest" one (see here for details).

Example usage

ZMK_KEYMAP(default_layer,
     // ╭─────────────┬─────────────┬─────────────┬─────────────┬─────────────╮   ╭─────────────┬─────────────┬─────────────┬─────────────┬─────────────╮
          &kp Q         &kp W         &kp F         &kp P         &kp B             &kp J         &kp L         &kp U         &kp Y         &kp SQT
     // ├─────────────┼─────────────┼─────────────┼─────────────┼─────────────┤   ├─────────────┼─────────────┼─────────────┼─────────────┼─────────────┤
          &hrm LGUI A   &hrm LALT R   &hrm LCTRL S  &hrm LSHFT T  &kp G             &kp M         &hrm RSHFT N  &hrm LCTRL E  &hrm LALT I   &hrm LGUI O
     // ├─────────────┼─────────────┼─────────────┼─────────────┼─────────────┤   ├─────────────┼─────────────┼─────────────┼─────────────┼─────────────┤
          &kp Z         &kp X         &kp C         &kp D         &kp V             &kp K         &kp H         &kp COMMA     &kp DOT       &kp SEMI
     // ╰─────────────┼─────────────┼─────────────┼─────────────┼─────────────┤   ├─────────────┼─────────────┼─────────────┼─────────────┼─────────────┤
                                      &kp ESC       &lt NAV SPACE &kp TAB           &kp RET       &ss_cw        &bs_del_num
     //                             ╰─────────────┴──── ────────┴─────────────╯   ╰─────────────┴─────────────┴─────────────╯
)

ZMK_COMBO

ZMK_COMBO defines new combos.

Syntax: ZMK_COMBO(name, bindings, keypos, layers)

• name: a unique identifier string chosen by the user (usually this isn't referenced elsewhere)
• binding: the binding triggered by the combo (this can be any stock or previously defined behavior)
• keypos: a list of 2 or more key positions that trigger the combo (e.g., 12 13). Note that the mapping from key positions to keys depends on your keyboard. To facilitate the combo set-up and increase portability, this repository provides shortcuts for some popular keyboards. See below on how to use them.
• layers: a list of layers for which the combo is active (e.g., 0 1 for the first two layers). If set to ALL the combo is active on all layers.

By default, the timeout for combos created with ZMK_COMBO is 30ms. If COMBO_TERM is set prior to calling ZMK_COMBO, the value of COMBO_TERM is used instead. Note: while it is possible to set different timeout for different combos, this is known to cause issues with overlapping combos and should be avoided.

Example: copy and paste combos

#define COMBO_TERM 50
ZMK_COMBO(copy,  &kp LC(C), 12 13, ALL)
ZMK_COMBO(paste, &kp LC(V), 13 14, ALL)

This sets the combo timeout to 50ms, and then creates two combos which both are active all layers. The first combo is triggered when the 12th and 13th keys are pressed jointly within the COMBO_TERM, sending Ctrl + C. The second combo is triggered when the 13th and 14th keys are pressed jointly, sending Ctrl + V.

ZMK_CONDITIONAL_LAYERS

This sets up tri-layer conditions.

Syntax: ZMK_CONDITIONAL_LAYERS(if_layers, then_layers)

• if_layers: a list of layers which trigger the then_layer if simultaneously active
• then_layer: the layer which is activated when the if-condition is met. Due to ZMK's layering model, it should generally have a higher number than the if_layers

For instance, this triggers "layer 3" if layers "1" and "2" are simultaneously active.

ZMK_CONDITIONAL_LAYERS(1 2, 3)

Mind that ZMK's layer numbering starts at 0! In general, it is recommended to use layer definitions, as demonstrated in example.keymap, to simplify life.

ZMK_UNICODE

There are two macros that simplify creating new unicode characters that can be added to the keymap. ZMK_UNICODE_SINGLE creates single unicode characters such as €, whereas ZMK_UNICODE_PAIR creates pairs of shifted/unshifted unicode characters that are useful for specifying international characters such as ä/Ä or δ/Δ.

Note that the input of unicode characters differs across operation systems. By default, ZMK_UNICODE is configured for Windows (using WinCompose). The easiest way to set up unicode characters for other operation systems is to set the variable HOST_OS before sourcing helper.h.

For Linux use:

#define HOST_OS 1  // set to 1 for Linux, default is 0 (Windows)
#include helper.h

For macOS use:

#define HOST_OS 2  // set to 2 for macOS, default is 0 (Windows)
#include helper.h

This will send unicode characters using the OS's default input channels. For non-default input channels or for other operation systems, one can instead set the variables OS_UNICODE_LEAD and OS_UNICODE_TRAIL to the character sequences that initialize/terminate the unicode input.

Syntax: ZMK_UNICODE_SINGLE(name, L0, L1, L2, L3)

• name: a unique string chosen by the user (e.g., my_char). The unicode character can be added to the keymap using &name (e.g., &my_char)
• L0 to L3: a 4-digit sequence defining the unicode string using standard ZMK key codes

Syntax: ZMK_UNICODE_PAIR(name, L0, L1, L2, L3, U0, U1, U2, U3)

• name: a unique string chosen by the user (e.g., my_char). The unicode character can be added to the keymap using &name (e.g., &my_char)
• L0 to L3: a 4-digit sequence defining the unshifted unicode string
• U0 to U3: a 4-digit sequence defining the shifted unicode string (which is send when holding Shift while pressing &name)

Note: 5-digit unicode characters are currently not supported.

Example 1: Euro sign (U+20AC)

ZMK_UNICODE_SINGLE(euro_sign, N2, N0, A, C)

The Euro character can be added to the keymap using &euro_sign.

Example 2: German umlauts (ä/Ä, ö/Ö, ü/Ü)

//                name  unshifted         shifted
ZMK_UNICODE_PAIR( ae,   N0, N0,  E, N4,   N0, N0,  C, N4 )
ZMK_UNICODE_PAIR( oe,   N0, N0,  F, N6,   N0, N0,  D, N6 )
ZMK_UNICODE_PAIR( ue,   N0, N0,  F,  C,   N0, N0,  D,  C )

The "umlaut"-pairs can be added to the keymap using &ae, &oe and &ue.

Dependencies for unicodes

• ZMK_UNICODE_PAIR requires a ZMK version patched with PR#1114 (not needed for ZMK_UNICODE_SINGLE). If you don't want to maintain your own ZMK repository, you can use ZMK's beta testing feature to configure Github Actions to build against a patched remote branch of ZMK. To do so, replace the contents of west.yml in your local zmk-config/config directory with the following contents:

  manifest:
    remotes:
      - name: urob
        url-base: https://github.com/urob
    projects:
      - name: zmk
        remote: urob
        revision: masked-mods
        import: app/west.yml
    self:
      path: config
  

• Depending on the operation system there are addition requirements for unicode input to work. On Windows, one must install WinCompose. On macOS one must enable unicode input in the system preferences.

International characters

There are pre-defined definitions for international characters for a few languages (currently German and Greek --- contributions are welcome!). These can be loaded by sourcing the corresponding files.

#include "../zmk-nodefree-config/international_chars/greek.dtsi"
#include "../zmk-nodefree-config/international_chars/german.dtsi"

These definitions make use of unicode in the background, please see the unicode documentation above for prerequisites. Once sourced, Greek and German characters can be added to the keymap using, e.g., &alpha, &upsilon, &tau or &omikron (see the language files for a complete list of available characters).

Key position shortcuts

Certain configuration options such as combos and positional hold-taps are based on the physical position of keys on your keyboard. This reduces portability of configuration files across keyboards with different layouts.

To increase portability, this repository comes with key position definitions for some popular keyboard layouts (48-key boards such as Planck, 42-key boards such as Corne, 36-key boards and 34-key boards).

These layouts provide a map from the physical key positions to human-readable shortcuts. All shortcuts are of the following form:

• L/R for Left/Right hand
• T/M/B/H for Top/Middle/Bottom and tHumb row.
• 0/1/2/3/4 for the finger position starting from the inside (0 is the inner index-finger column, 1 is the home position of the index finger, ..., 4 is the home position of the pinkie)

For instance, the shortcuts layout for a 36-key board looks as follows:

╭─────────────────────┬─────────────────────╮
│ LT4 LT3 LT2 LT1 LT0 │ RT0 RT1 RT2 RT3 RT4 │
│ LM4 LM3 LM2 LM1 LM0 │ RM0 RM1 RM2 RM3 RM4 │
│ LB4 LB3 LB2 LB1 LB0 │ RB0 RB1 RB2 RB3 RB4 │
╰───────╮ LH2 LH1 LH0 │ RH0 RH1 RH2 ╭───────╯
        ╰─────────────┴─────────────╯

Schematics for all existing layout files can be found at the top of the corresponding definition files.

To use these shortcut definitions, source the definition file for your keyboard into your .keymap file. E.g., for a 36-key board, use:

#include "../zmk-nodefree-config/keypos_def/keypos_36keys.h"

Example 1: Defining combos using key position shortcuts

ZMK_COMBO(copy,  &kp LC(C), LB2 LB3, ALL)
ZMK_COMBO(paste, &kp LC(V), LB1 LB2, ALL)

This defines a "copy"-combo for the middle + ring finger on the left bottom row, and a "paste"-combo for the index + middle finger on the left bottom row. Both combos are active on all layers.

Example 2: Home-row mods with positional hold-taps

Here we use ZMK's positional hold-tap feature to make home-row mods only trigger with "opposite hand" keys.¹ Using our positional shortcuts makes this straightforward:

#define HRM_LT LM1 LM2 LM3 LM4                                      // left-hand HRMs
#define HRM_RT RM1 RM2 RM3 RM4                                      // right-hand HRMs
#define KEYS_LT LT0 LT1 LT2 LT3 LT4 LM0 HRM_LT LB0 LB1 LB2 LB3 LB4  // left-hand keys
#define KEYS_RT RT0 RT1 RT2 RT3 RT4 RM0 HRM_RT RB0 RB1 RB2 RB3 RB4  // right-hand keys
#define THUMBS LH2 LH1 LH0 RH0 RH1 RH2                              // thumb keys

ZMK_BEHAVIOR(hml, hold_tap,  // left-hand HRMs
    flavor = "balanced";
    tapping-term-ms = <280>;
    quick-tap-ms = <125>;
    global-quick-tap;
    bindings = <&kp>, <&kp>;
    hold-trigger-key-positions = <KEYS_RT THUMBS HRM_LT>;  // include left-hand HRMs for chording
)

ZMK_BEHAVIOR(hmr, hold_tap,  // right-hand HRMs
    flavor = "balanced";
    tapping-term-ms = <280>;
    quick-tap-ms = <125>;
    global-quick-tap;
    bindings = <&kp>, <&kp>;
    hold-trigger-key-positions = <KEYS_LT THUMBS HRM_RT>;  // include right-hand HRMs for chording
)

---

1. We also whitelist same-hand HRMs so that we can combine them to chord mods. ↩︎