Enable sync of OLED/ST7565 display on/off state on Splits (#13542)

* Enable sync of OLED/ST7565 display on/off state on Splits

* Only send if states are not matched

Co-authored-by: Nick Brassel <nick@tzarc.org>

Co-authored-by: Nick Brassel <nick@tzarc.org>

2 files changed, 18 insertions, 0 deletions

diff --git a/docs/config_options.md b/docs/config_options.md
index 78c1f70fd..94f99e74c 100644
--- a/docs/config_options.md
+++ b/docs/config_options.md
@@ -343,6 +343,12 @@ There are a few different ways to set handedness for split keyboards (listed in
 * `#define SPLIT_WPM_ENABLE`
   * Ensures the current WPM is available on the slave when using the QMK-provided split transport.
 
+* `#define SPLIT_OLED_ENABLE`
+  * Syncs the on/off state of the OLED between the halves.
+
+* `#define SPLIT_ST7565_ENABLE`
+  * Syncs the on/off state of the ST7565 screen between the halves.
+
 * `#define SPLIT_TRANSACTION_IDS_KB .....`
 * `#define SPLIT_TRANSACTION_IDS_USER .....`
   * Allows for custom data sync with the slave when using the QMK-provided split transport. See [custom data sync between sides](feature_split_keyboard.md#custom-data-sync) for more information.
diff --git a/docs/feature_split_keyboard.md b/docs/feature_split_keyboard.md
index 428d581ca..a84d38460 100644
--- a/docs/feature_split_keyboard.md
+++ b/docs/feature_split_keyboard.md
@@ -233,6 +233,18 @@ This enables transmitting modifier state (normal, weak and oneshot) to the non p
 
 This enables transmitting the current WPM to the slave side of the split keyboard. The purpose of this feature is to support cosmetic use of WPM (e.g. displaying the current value on an OLED screen). This adds overhead to the split communication protocol and may negatively impact the matrix scan speed when enabled. 
 
+```c
+#define SPLIT_OLED_ENABLE
+```
+
+This enables transmitting the current OLED on/off status to the slave side of the split keyboard. The purpose of this feature is to support state (on/off state only) syncing. This adds overhead to the split communication protocol and may negatively impact the matrix scan speed when enabled. 
+
+```c
+#define SPLIT_ST7565_ENABLE
+```
+
+This enables transmitting the current ST7565 on/off status to the slave side of the split keyboard. The purpose of this feature is to support state (on/off state only) syncing. This adds overhead to the split communication protocol and may negatively impact the matrix scan speed when enabled. 
+
 ### Custom data sync between sides :id=custom-data-sync
 
 QMK's split transport allows for arbitrary data transactions at both the keyboard and user levels. This is modelled on a remote procedure call, with the master invoking a function on the slave side, with the ability to send data from master to slave, process it slave side, and send data back from slave to master.