[Docs] Improve Handedness by EEPROM documentation (#15615)

Co-authored-by: Dasky <32983009+daskygit@users.noreply.github.com>
Co-authored-by: filterpaper <filterpaper@localhost>

1 files changed, 16 insertions, 9 deletions

diff --git a/docs/feature_split_keyboard.md b/docs/feature_split_keyboard.md
index c8ba18bee..dbc7740f9 100644
--- a/docs/feature_split_keyboard.md
+++ b/docs/feature_split_keyboard.md
@@ -130,14 +130,17 @@ To enable this method, add the following to your `config.h` file:
 #define EE_HANDS
 ```
 
-However, you'll have to flash the EEPROM files for the correct hand to each controller.  You can do this manually, or there are targets for avrdude and dfu to do this, while flashing the firmware: 
-
-* `:avrdude-split-left`
-* `:avrdude-split-right`
-* `:dfu-split-left`
-* `:dfu-split-right`
-* `:dfu-util-split-left`
-* `:dfu-util-split-right`
+Next, you will have to flash the EEPROM files once for the correct hand to the controller on each halve. You can do this manually with the following bootloader targets while flashing the firmware:
+
+* AVR controllers with the Caterina bootloader (e.g. Pro Micro):
+  * `:avrdude-split-left`
+  * `:avrdude-split-right`
+* AVR controllers with the stock Amtel DFU or DFU compatible bootloader (e.g. Elite-C):
+  * `:dfu-split-left`
+  * `:dfu-split-right`
+* ARM controllers with a DFU compatible bootloader (e.g. Proton-C):
+  * `:dfu-util-split-left`
+  * `:dfu-util-split-right`
 
 Example:
 
@@ -145,9 +148,13 @@ Example:
 make crkbd:default:avrdude-split-left
 ```
 
+?> ARM controllers using `dfu-util` will require an EEPROM reset after setting handedness. This can be done using the `EEP_RST` keycode or [Bootmagic Lite](feature_bootmagic.md). Controllers using emulated EEPROM will always require handedness parameter when flashing the firmware.
+
+?> [QMK Toolbox]() can also be used to flash EEPROM handedness files. Place the controller in bootloader mode and select menu option Tools -> EEPROM -> Set Left/Right Hand
+
 This setting is not changed when re-initializing the EEPROM using the `EEP_RST` key, or using the `eeconfig_init()` function.  However, if you reset the EEPROM outside of the firmware's built in options (such as flashing a file that overwrites the `EEPROM`, like how the [QMK Toolbox]()'s "Reset EEPROM" button works), you'll need to re-flash the controller with the `EEPROM` files. 
 
-You can find the `EEPROM` files in the QMK firmware repo, [here](https://github.com/qmk/qmk_firmware/tree/master/quantum/split_common). 
+You can find the `EEPROM` files in the QMK firmware repo, [here](https://github.com/qmk/qmk_firmware/tree/master/quantum/split_common).
 
 #### Handedness by `#define`