KMK is configured through a rather large plain-old-Python class called
KMKKeyboard. Subclasses of this configuration exist which pre-fill defaults
for various known keyboards (for example, many QMK, TMK, or ZMK keyboards
are supported with a nice!nano, or through our ItsyBitsy to Pro Micro pinout adapter.)
This class is the main interface between end users and the inner workings of KMK.
Let's dive in!
Edit or create a file called
CIRCUITPYdrive. You can also keep this file on your computer (perhaps under
user_keymaps- please feel free to submit a pull request with your layout definitions!) and copy it over (either manually or, if you're adept with developer tooling and/or a command line, our Makefile). It's definitely recommended to keep a backup of your configuration somewhere that isn't the microcontroller itself - MCUs die, CircuitPython may run into corruption bugs, or you might just have bad luck and delete the wrong file some day.
KMKKeyboardinstance to a variable (ex.
keyboard = KMKKeyboard()- note the parentheses)
Make sure this
KMKKeyboardinstance is actually run at the end of the file with a block such as the following:
if __name__ == '__main__':
- Assign pins and your diode orientation (only necessary on handwire keyboards), for example:
from kmk.scanners import DiodeOrientation
col_pins = (board.SCK, board.MOSI, board.MISO, board.RX, board.TX, board.D4)
row_pins = (board.D10, board.D11, board.D12, board.D13, board.D9, board.D6, board.D5, board.SCL)
rollover_cols_every_rows = 4
diode_orientation = DiodeOrientation.COL2ROW
The pins should be based on whatever CircuitPython calls pins on your particular board. You can find these in the REPL on your CircuitPython device:
rollover_cols_every_rowsis only supported with
DiodeOrientation.ROW2COL. It is used for boards such as the Planck Rev6 which reuse column pins to simulate a 4x12 matrix in the form of an 8x6 matrix
Import the global list of key definitions with
from kmk.keys import KC. You can either print this out in the REPL as we did with
boardabove, or simply look at our Key documentation. We've tried to keep that listing reasonably up to date, but if it feels like something is missing, you may need to read through
kmk/keys.py(and then open a ticket to tell us our docs are out of date, or open a PR and fix the docs yourself!)
Define a keymap, which is, in Python terms, a List of Lists of
Keyobjects. A very simple keymap, for a keyboard with just two physical keys on a single layer, may look like this:
keyboard.keymap = [[KC.A, KC.B]]
You can further define a bunch of other stuff:
keyboard.debug_enabledwhich will spew a ton of debugging information to the serial console. This is very rarely needed, but can provide very valuable information if you need to open an issue.
keyboard.tap_timewhich defines how long
KC.LTwill wait before considering a key "held" (see