Inspired by a similar feature on other keyboards, the EEPROM-Keymap-Programmer plugin implements an on-device keymap re-arrangement / re-coding system. There are two modes of operation: in one, we need to press a key we want to change, then another to copy from. In the other, we press a key to change, and then input a key code (terminated by any non-number key).

The two modes of operation

It is worth looking at the two separately, to better understand how they work, and what they accomplish:

Copy mode

In COPY mode, the plugin will use both the built-in, default keymap, and the override stored in EEPROM. When we select a key to override, we need to tap another, which will be used as the source. The source key’s code will be looked up from the built-in keymap. For example, lets say we want to swap A and B for some odd reason. We can do this by triggering the keymap programmer mode, then tapping A to select it as the destination, then B as the source. The plugin will look up the keycode in the built-in keymap for the key in B’s location, and replace the location of A in the override with it. Next, we press the B key to select it as the destination, and we press the key that used to be A (but is now B too) to select it as a source. Because source keys are looked up in the built-in keymap, the plugin will find it is A.

Obviously, this method only works if we have a built-in keymap, and it does not support copying from another layer. It is merely a way to rearrange simple things, like alphanumerics.

Code mode

In CODE mode, instead of selecting a source key, we need to enter a code: press numbers to input the code, and any non-number key to end the sequence. Thus, when entering keymap programmer mode, and selecting, say, the A key, then tapping 5 SPACE will set the key to B (which has the keycode of 5).

This allows us to use keycodes not present on the built-in keymap, at the expense of having to know the keycode, and allowing no mistakes.

Using the plugin

Adding the functionality of the plugin to a Sketch is easier the usage explained above, though it requires that the EEPROM-Keymap plugin is also used, and set up appropriately.

Once the prerequisites are dealt with, all we need to do is to use the plugin, and find a way to trigger entering the keymap programmer mode. One such way is to use a macro, as in the example below:

#include <Kaleidoscope.h>
#include <Kaleidoscope-EEPROM-Keymap.h>
#include <Kaleidoscope-EEPROM-Keymap-Programmer.h>
#include <Kaleidoscope-EEPROM-Settings.h>
#include <Kaleidoscope-Macros.h>

const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState) {
  if (macroIndex == 0 && keyToggledOff(keyState)) {

  return MACRO_NONE;


void setup() {

  Layer.getKey = EEPROMKeymap.getKey;


The plugin should be used as early as possible, otherwise other plugins that hook into the event system may start processing events before the programmer can take over.

Plugin methods

The plugin provides the EEPROMKeymapProgrammer object, which has the following methods and properties:


Activates the keymap programmer. This is the function one needs to call from - say - a macro, to enter the edit state.


Set this property to the mode to use for editing: either kaleidoscope::EEPROMKeymapProgrammer::COPY, or kaleidoscope::EEPROMKeymapProgrammer::CODE.

Defaults to kaleidoscope::EEPROMKeymapProgrammer::CODE.

Focus commands

The plugin provides a single Focus hook: FOCUS_HOOK_KEYMAP_PROGRAMMER, which in turn provides the following command:


Toggles the programmer mode on or off.


Further reading

Starting from the example is the recommended way of getting started with the plugin.