hhkb_qmk keyboard firmware

Quantum MK Firmware

You have access to a bunch of goodies! Check out the Makefile to enable/disable some of the features. Uncomment the # to enable them. Setting them to no does nothing and will only confuse future you.

BACKLIGHT_ENABLE = yes # Enable keyboard backlight functionality
MIDI_ENABLE = yes      # MIDI controls
# UNICODE_ENABLE = yes # Unicode support - this is commented out, just as an example. You have to use #, not //
BLUETOOTH_ENABLE = yes # Enable Bluetooth with the Adafruit EZ-Key HID

Quick aliases to common actions

Your keymap can include shortcuts to common operations (called "function actions" in tmk).

Switching and toggling layers

MO(layer) - momentary switch to layer. As soon as you let go of the key, the layer is deactivated and you pop back out to the previous layer. When you apply this to a key, that same key must be set as KC_TRNS on the destination layer. Otherwise, you won't make it back to the original layer when you release the key (and you'll get a keycode sent). You can only switch to layers above your current layer. If you're on layer 0 and you use MO(1), that will switch to layer 1 just fine. But if you include MO(3) on layer 5, that won't do anything for you -- because layer 3 is lower than layer 5 on the stack.

LT(layer, kc) - momentary switch to layer when held, and kc when tapped. Like MO(), this only works upwards in the layer stack (layer must be higher than the current layer).

TG(layer) - toggles a layer on or off. As with MO(), you should set this key as KC_TRNS in the destination layer so that tapping it again actually toggles back to the original layer. Only works upwards in the layer stack.

Fun with modifier keys

  • LSFT(kc) - applies left Shift to kc (keycode) - S(kc) is an alias
  • RSFT(kc) - applies right Shift to kc
  • LCTL(kc) - applies left Control to kc
  • RCTL(kc) - applies right Control to kc
  • LALT(kc) - applies left Alt to kc
  • RALT(kc) - applies right Alt to kc
  • LGUI(kc) - applies left GUI (command/win) to kc
  • RGUI(kc) - applies right GUI (command/win) to kc

You can also chain these, like this:

LALT(LCTL(KC_DEL)) -- this makes a key that sends Alt, Control, and Delete in a single keypress.

The following shortcuts automatically add LSFT() to keycodes to get commonly used symbols. Their long names are also available and documented in /quantum/keymap_common.h.

KC_AT    @
KC_DLR   $

MT(mod, kc) - is mod (modifier key - MOD_LCTL, MOD_LSFT) when held, and kc when tapped. In other words, you can have a key that sends Esc (or the letter O or whatever) when you tap it, but works as a Control key or a Shift key when you hold it down.

These are the values you can use for the mod in MT() (right-hand modifiers are not available):


These can also be combined like MOD_LCTL | MOD_LSFT e.g. MT(MOD_LCTL | MOD_LSFT, KC_ESC) which would activate Control and Shift when held, and send Escape when tapped.

We've added shortcuts to make common modifier/tap (mod-tap) mappings more compact:

  • CTL_T(kc) - is LCTL when held and kc when tapped
  • SFT_T(kc) - is LSFT when held and kc when tapped
  • ALT_T(kc) - is LALT when held and kc when tapped
  • GUI_T(kc) - is LGUI when held and kc when tapped
  • ALL_T(kc) - is Hyper (all mods) when held and kc when tapped. To read more about what you can do with a Hyper key, see this blog post by Brett Terpstra

Temporarily setting the default layer

DF(layer) - sets default layer to layer. The default layer is the one at the "bottom" of the layer stack - the ultimate fallback layer. This currently does not persist over power loss. When you plug the keyboard back in, layer 0 will always be the default. It is theoretically possible to work around that, but that's not what DF does.

Remember: These are just aliases

These functions work the same way that their ACTION_* functions do - they're just quick aliases. To dig into all of the tmk ACTION_* functions, please see the TMK documentation.

Instead of using FNx when defining ACTION_* functions, you can use F(x) - the benefit here is being able to use more than 32 function actions (up to 4096), if you happen to need them.

Macro shortcuts: Send a whole string when pressing just one key

Instead of using the ACTION_MACRO function, you can simply use M(n) to access macro n - n will get passed into the action_get_macro as the id, and you can use a switch statement to trigger it. This gets called on the keydown and keyup, so you'll need to use an if statement testing record->event.pressed (see keymap_default.c).

const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) // this is the function signature -- just copy/paste it into your keymap file as it is.
  switch(id) {
    case 0: // this would trigger when you hit a key mapped as M(0)
      if (record->event.pressed) {
        return MACRO( I(255), T(H), T(E), T(L), T(L), W(255), T(O), END  ); // this sends the string 'hello' when the macro executes
  return MACRO_NONE;

A macro can include the following commands:

  • I() change interval of stroke in milliseconds.
  • D() press key.
  • U() release key.
  • T() type key(press and release).
  • W() wait (milliseconds).
  • END end mark.

So above you can see the stroke interval changed to 255ms between each keystroke, then a bunch of keys being typed, waits a while, then the macro ends.

Note: Using macros to have your keyboard send passwords for you is a bad idea.

Additional keycode aliases for software-implemented layouts (Colemak, Dvorak, etc)

Everything is assuming you're in Qwerty (in software) by default, but there is built-in support for using a Colemak or Dvorak layout by including this at the top of your keymap:

#include "keymap_.h"

Where is "colemak" or "dvorak". After including this line, you will get access to:

  • CM_* for all of the Colemak-equivalent characters
  • DV_* for all of the Dvorak-equivalent characters

These implementations assume you're using Colemak or Dvorak on your OS, not on your keyboard - this is referred to as a software-implemented layout. If your computer is in Qwerty and your keymap is in Colemak or Dvorak, this is referred to as a firmware-implemented layout, and you won't need these features.

To give an example, if you're using software-implemented Colemak, and want to get an F, you would use CM_F - KC_F under these same circumstances would result in T.

Additional language support

In quantum/keymap_extras/, you'll see various language files - these work the same way as the alternative layout ones do. Most are defined by their two letter country/language code followed by an underscore and a 4-letter abbreviation of its name. FR_UGRV which will result in a รน when using a software-implemented AZERTY layout. It's currently difficult to send such characters in just the firmware (but it's being worked on - see Unicode support).

Unicode support

You can currently send 4 hex digits with your OS-specific modifier key (RALT for OSX with the "Unicode Hex Input" layout) - this is currently limited to supporting one OS at a time, and requires a recompile for switching. 8 digit hex codes are being worked on. The keycode function is UC(n), where n is a 4 digit hexidecimal. Enable from the Makefile.

Other firmware shortcut keycodes

  • RESET - puts the MCU in DFU mode for flashing new firmware (with make dfu)
  • DEBUG - the firmware into debug mode - you'll need hid_listen to see things
  • BL_ON - turns the backlight on
  • BL_OFF - turns the backlight off
  • BL_<n> - sets the backlight to level n
  • BL_INC - increments the backlight level by one
  • BL_DEC - decrements the backlight level by one
  • BL_TOGG - toggles the backlight
  • BL_STEP - steps through the backlight levels

Enable the backlight from the Makefile.

MIDI functionalty

This is still a WIP, but check out quantum/keymap_midi.c to see what's happening. Enable from the Makefile.

Bluetooth functionality

This requires some hardware changes, but can be enabled via the Makefile. The firmware will still output characters via USB, so be aware of this when charging via a computer. It would make sense to have a switch on the Bluefruit to turn it off at will.


Download or clone the whole firmware and navigate to the keyboards/planck folder. Once your dev env is setup, you'll be able to type make to generate your .hex - you can then use make dfu to program your PCB once you hit the reset button.

Depending on which keymap you would like to use, you will have to compile slightly differently.


To build with the default keymap, simply run make default.

Other Keymaps

Several version of keymap are available in advance but you are recommended to define your favorite layout yourself. To define your own keymap create a file in the keymaps folder named <name>.c and see keymap document (you can find in top readme.md) and existent keymap files.

To build the firmware binary hex file with a keymap just do make with a keymap like this:

$ make [default|jack|<name>]

Keymaps follow the format \.c and are stored in the keymaps folder.