ZMK Heatmap Generator

A heatmap generator for ZMK keyboards.

Generating a heatmap is done in two steps:

1. Extract your keymap: in order to properly parse combo's as combo's instead of two keystrokes we need to load your keymap.

   Generate your keymap with https://github.com/hnaderi/keymap-drawer/

   keymap parse -c 10 -z <your-zmk-config-project>/config/corne.keymap > keymap.yaml 
   

2. Process your keystrokes: this is the process of listening to all of your keystrokes and collection the amount each key is pressed and storing this in a file. Since we only store the amount each key is pressed it should be safe and no passwords or any other sensitive information will be stored or derivable.

   First make sure that USB_LOGGING is enabled on your keyboard, see: [#Enable USB logging in your keyboard](Enable USB logging in your keyboard) below.

   Next start the collection by running the command and point to your keymap.yaml:

   zmk-heatmap collect --keymap=keymap.yaml
   

3. Generating the heatmap: taking all the keystrokes into account the heatmap can now be created:

   zmk-heatmap generate
   

4. Create the keymap config: copy the output from the zmk-heatmap generate and add it in the svg_extra_style.

   For an example see: https://github.com/MarijnKoesen/zmk-config/blob/main/.keymap.config.ferris-sweep.yaml

   I'm planning to integrate this nicer in the future, but for now it's a bit of a manual copy/paste.

Enable USB logging in your keyboard

In order to generate the heatmap we need to know which keys are pressed. We cannot do this by listening to the keystrokes alone as we'd loose any information on layers etc.

So this is done by listening to the USB_LOGGING output from your ZMK keyboard.

To enable this option set the following parameters in your config/*.conf file:

CONFIG_ZMK_USB_LOGGING=y
CONFIG_LOG_BUFFER_SIZE=31768
CONFIG_LOG_PROCESS_THREAD_SLEEP_MS=10
CONFIG_LOG_SPEED=y

Next build the firmware and flash your keyboard.

Example heatmap