From 82be3579fd2e69b786582cc152d8ae7ca0283355 Mon Sep 17 00:00:00 2001
From: daskygit <32983009+daskygit@users.noreply.github.com>
Date: Tue, 31 May 2022 17:01:48 +0100
Subject: [PATCH 1/3] Move SPLIT_HAND_PIN setup to split_pre_init

---
 quantum/split_common/split_util.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/quantum/split_common/split_util.c b/quantum/split_common/split_util.c
index 7d50adf758fb..2fc3a9986c4b 100644
--- a/quantum/split_common/split_util.c
+++ b/quantum/split_common/split_util.c
@@ -93,7 +93,6 @@ static uint8_t peek_matrix_intersection(pin_t out_pin, pin_t in_pin) {
 __attribute__((weak)) bool is_keyboard_left(void) {
 #if defined(SPLIT_HAND_PIN)
     // Test pin SPLIT_HAND_PIN for High/Low, if low it's right hand
-    setPinInput(SPLIT_HAND_PIN);
 #    ifdef SPLIT_HAND_PIN_LOW_IS_LEFT
     return !readPin(SPLIT_HAND_PIN);
 #    else
@@ -132,6 +131,10 @@ __attribute__((weak)) bool is_keyboard_master(void) {
 
 // this code runs before the keyboard is fully initialized
 void split_pre_init(void) {
+#if defined(SPLIT_HAND_PIN)
+    setPinInput(SPLIT_HAND_PIN);
+    wait_us(100);
+#endif
     isLeftHand = is_keyboard_left();
 
 #if defined(RGBLIGHT_ENABLE) && defined(RGBLED_SPLIT)

From 92380f1bdbb379c66f48d0263410e8704d52a20a Mon Sep 17 00:00:00 2001
From: Dasky <32983009+daskygit@users.noreply.github.com>
Date: Sun, 5 Jun 2022 23:21:12 +0100
Subject: [PATCH 2/3] doppelganger should use old behaviour

---
 keyboards/doppelganger/doppelganger.c | 35 +++++++++++++++------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/keyboards/doppelganger/doppelganger.c b/keyboards/doppelganger/doppelganger.c
index 04d19480daab..de3849e383ad 100644
--- a/keyboards/doppelganger/doppelganger.c
+++ b/keyboards/doppelganger/doppelganger.c
@@ -15,25 +15,30 @@
  */
 #include "doppelganger.h"
 
-void keyboard_pre_init_kb (void) {
-  setPinOutput(C6);
-  setPinOutput(B0);
+void keyboard_pre_init_kb(void) {
+    setPinOutput(C6);
+    setPinOutput(B0);
 }
 
 bool led_update_kb(led_t led_state) {
-  bool res = led_update_user(led_state);
-  if(res) {
-    // writePin sets the pin high for 1 and low for 0.
-    // In this example the pins are inverted, setting
-    // it low/0 turns it on, and high/1 turns the LED off.
-    // This behavior depends on whether the LED is between the pin
-    // and VCC or the pin and GND.
-    writePin(C6, !led_state.caps_lock);
-  }
-  return res;
+    bool res = led_update_user(led_state);
+    if (res) {
+        // writePin sets the pin high for 1 and low for 0.
+        // In this example the pins are inverted, setting
+        // it low/0 turns it on, and high/1 turns the LED off.
+        // This behavior depends on whether the LED is between the pin
+        // and VCC or the pin and GND.
+        writePin(C6, !led_state.caps_lock);
+    }
+    return res;
 }
 
 __attribute__((weak)) layer_state_t layer_state_set_user(layer_state_t state) {
-  writePin(B0, !(state & (1UL << 1)));
-  return state;
+    writePin(B0, !(state & (1UL << 1)));
+    return state;
+}
+
+bool is_keyboard_left(void) {
+    setPinInput(SPLIT_HAND_PIN);
+    return readPin(SPLIT_HAND_PIN);
 }

From f5a8f1857caf73e951ff36e77598cb8512b2a1b1 Mon Sep 17 00:00:00 2001
From: Dasky <32983009+daskygit@users.noreply.github.com>
Date: Mon, 6 Jun 2022 01:05:37 +0100
Subject: [PATCH 3/3] Add comment for future

Co-authored-by: Joel Challis <git@zvecr.com>
---
 keyboards/doppelganger/doppelganger.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/keyboards/doppelganger/doppelganger.c b/keyboards/doppelganger/doppelganger.c
index de3849e383ad..304d764028a1 100644
--- a/keyboards/doppelganger/doppelganger.c
+++ b/keyboards/doppelganger/doppelganger.c
@@ -38,6 +38,7 @@ __attribute__((weak)) layer_state_t layer_state_set_user(layer_state_t state) {
     return state;
 }
 
+// Override core logic as we reuse SPLIT_HAND_PIN within matrix pins
 bool is_keyboard_left(void) {
     setPinInput(SPLIT_HAND_PIN);
     return readPin(SPLIT_HAND_PIN);