From 798bd98fe032c5bc3268027877b528d47dc413f9 Mon Sep 17 00:00:00 2001
From: coliss86 <coliss86@users.noreply.github.com>
Date: Sun, 19 Jun 2022 00:32:22 +0200
Subject: [PATCH] Add a note about using differents MCU family (#17416)

---
 docs/feature_split_keyboard.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docs/feature_split_keyboard.md b/docs/feature_split_keyboard.md
index 6ef70bf788f9..eefafdbf7573 100644
--- a/docs/feature_split_keyboard.md
+++ b/docs/feature_split_keyboard.md
@@ -10,6 +10,8 @@ For this, we will mostly be talking about the generic implementation used by the
 
 !> ARM split supports most QMK subsystems when using the 'serial' and 'serial_usart' drivers. I2C slave is currently unsupported.
 
+!> Both sides must use the same MCU family, for eg two Pro Micro-compatible controllers or two Blackpills. Currently, mixing AVR and ARM is not possible as ARM vs AVR uses different method for serial communication, and are not compatible. Moreover Blackpill's uses 3.3v logic, and atmega32u4 uses 5v logic.
+
 ## Compatibility Overview
 
 | Transport                    | AVR                | ARM                |