Fix cross-half reactive RGB splash on BCORNE split.

Mirror master matrix state and sync remote keypresses to rgb_matrix so splash propagates from the left half onto the right, and close the LED coordinate gap at the split seam.

Co-authored-by: Cursor <cursoragent@cursor.com>

corne/firmware/config.h

@@ -74,6 +74,7 @@
 #define SPLIT_HAND_PIN C1
 //#define SPLIT_LAYER_STATE_ENABLE
 #define SPLIT_HAND_PIN_LOW_IS_LEFT
+#define SPLIT_TRANSPORT_MIRROR // reactive RGB needs master matrix mirrored to slave
 
 
 //#define SPLIT_LED_STATE_ENABLE
@@ -89,7 +90,6 @@
 #    define WS2812_DMA_CHANNEL 5  // DMA Channel for TIMx_UP, see the respective reference manual for the appropriate values for your MCU.
 //#    define WS2812_DMAMUX_ID STM32_DMAMUX1_TIM2_UP // DMAMUX configuration for TIMx_UP -- only required if your MCU has a DMAMUX peripheral, see the respective reference manual for the appropriate values for your MCU.
 #define RGB_MATRIX_SLEEP
-#define RGB_MATRIX_VAL_STEP 1
 
 #define WEAR_LEVELING_LOGICAL_SIZE 2048
 #define WEAR_LEVELING_BACKING_SIZE (WEAR_LEVELING_LOGICAL_SIZE * 2)

corne/firmware/m57.c

@@ -46,16 +46,19 @@ led_config_t g_led_config = {
 led_config_t g_led_config = {
     {
 
-         { 0,  1,  2,  3,  4 , 5,  NO_LED },
+         // matrix rows 0-4 = left half, rows 5-9 = right half (sequential, not paired)
-         { NO_LED, 29, 30, 31, 32, 33, 34 },
+         // chain order (left): top(0-5) > Q row(6-11) > PgUp(12) > home row(13-18) > Mute(19) > Z row(20-25) > thumbs(26-28)
-         { 6,  7,  8,  9,  10, 11, 12 },
+         // PgDn (matrix 2,6) has no under-key LED. right half mirrored.
-         { 35, 36, 37, 38, 39, 40, 41 },
+         { 0,      1,      2,      3,      4,      5,      NO_LED },                // matrix row 0: L top row (Esc/1/2/3/4/5)
-         { 13, 14, 15, 16, 17, 18, 19 },
+         { 6,      7,      8,      9,      10,     11,     12 },                    // matrix row 1: L Q row + PgUp (LED 12 at (1,6))
-         { 42, 43, 44, 45, 46, 47, 48 },
+         { 13,     14,     15,     16,     17,     18,     19 },                    // matrix row 2: L home row + PgDn (LED 19 at (2,6))
-         { 20, 21, 22, 23, 24, 25, NO_LED },
+         { 20,     21,     22,     23,     24,     25,     NO_LED },                // matrix row 3: L Z row, Mute no LED (no LED at (3,6))
-         { NO_LED, 49, 50,51, 52, 53, 54 },
+         { NO_LED, NO_LED, NO_LED, 26,     27,     28,     NO_LED },                // matrix row 4: L thumbs - Del=26, MO(1)=27, Space=28
-         { NO_LED, NO_LED, NO_LED, 26, 27,28,NO_LED },
+         { NO_LED, 29,     30,     31,     32,     33,     34 },                    // matrix row 5: R top row (cols ascending)
-         { NO_LED, 55, 56, 57 , NO_LED,NO_LED, NO_LED },
+         { 35,     36,     37,     38,     39,     40,     41 },                    // matrix row 6: R Q row + "{[" (cols 0-6 ascending, all align matrix col)
+         { 42,     43,     44,     45,     46,     47,     48 },                    // matrix row 7: R home row + MediaPlay (cols 0-6 ascending)
+         { NO_LED, 49,     50,     51,     52,     53,     54 },                    // matrix row 8: R Z row, "}]" no LED (col 0 silent, cols 1-6 ascending)
+         { NO_LED, 55,     56,     57,     NO_LED, NO_LED, NO_LED },                // matrix row 9: R thumbs - Enter=55, MO(3)=56, Bksp=57 (mirror)
 
     },
 
@@ -67,11 +70,12 @@ led_config_t g_led_config = {
          {0,51},   {16,51}, {32,51}, {48,51}, {64,51},{80,51},               //            {128,51}, {144,51}, {160,51}, {178,51},{194,51}, {210,51},
                             {32,63}, {48,63}, {64,63},              // {112,63},   {128,63}, {144,63}, {160,63}, {178,63},
 
-                     {128,12}, {144,12}, {160,12}, {178,12},{194,12}, {210,12},
+         // Right-half x coords overlap left inner edge (96) so splash crosses the split
-         {112,25},   {128,25}, {144,25}, {160,25}, {178,25},{194,25}, {210,25},
+                     {112,12}, {128,12}, {144,12}, {162,12},{178,12}, {194,12},
-         {112,38},   {128,38}, {144,38}, {160,38}, {178,38},{194,38}, {210,38},
+         {96,25},    {112,25}, {128,25}, {144,25}, {162,25},{178,25}, {194,25},
-                     {128,51}, {144,51}, {160,51}, {178,51},{194,51}, {210,51},
+         {96,38},    {112,38}, {128,38}, {144,38}, {162,38},{178,38}, {194,38},
-                     {112,63}, {128,63}, {144,63},
+                     {112,51}, {128,51}, {144,51}, {162,51},{178,51}, {194,51},
+                     {96,63},  {112,63}, {128,63},
      },
 
  {

corne/firmware/matrix.c

@@ -26,6 +26,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #    include "split_common/split_util.h"
 #    include "split_common/transactions.h"
 
+#ifdef RGB_MATRIX_ENABLE
+#    include "rgb_matrix.h"
+#endif
+
 #    define ROWS_PER_HAND (MATRIX_ROWS / 2)
 
 
@@ -229,6 +233,45 @@ bool is_keyboard_master_impl(void) {
 
 static bool  last_connected              = false;
 uint32_t counter1 = 1;
+
+#ifdef RGB_MATRIX_ENABLE
+static void rgb_matrix_sync_remote_half(matrix_row_t remote_prev[ROWS_PER_HAND], uint8_t remote_offset) {
+    for (uint8_t r = 0; r < ROWS_PER_HAND; r++) {
+        const uint8_t      row     = remote_offset + r;
+        const matrix_row_t current = matrix[row];
+        const matrix_row_t delta   = current ^ remote_prev[r];
+
+        if (!delta) {
+            continue;
+        }
+
+        matrix_row_t col_mask = 1;
+        for (uint8_t col = 0; col < MATRIX_COLS; col++, col_mask <<= 1) {
+            if (delta & col_mask) {
+                rgb_matrix_handle_key_event(row, col, current & col_mask);
+            }
+        }
+
+        remote_prev[r] = current;
+    }
+}
+#endif
+
+void matrix_scan_kb(void) {
+#ifdef RGB_MATRIX_ENABLE
+    static matrix_row_t master_remote_prev[ROWS_PER_HAND] = {0};
+    static matrix_row_t slave_mirror_prev[ROWS_PER_HAND]  = {0};
+
+    if (is_keyboard_master()) {
+        rgb_matrix_sync_remote_half(master_remote_prev, thatHand);
+    } else {
+        rgb_matrix_sync_remote_half(slave_mirror_prev, thatHand);
+    }
+#endif
+
+    matrix_scan_user();
+}
+
 bool matrix_post_scan_qf(void) {
     counter1++;
     bool changed = false;
@@ -248,8 +291,6 @@ bool matrix_post_scan_qf(void) {
         }
 
         if (changed) memcpy(matrix + thatHand, slave_matrix, sizeof(slave_matrix));
-
-        matrix_scan_kb();
     } else {
          if(counter1 % 15000 ==0){
             // extern  bool usb_bus_detected(void);
@@ -262,11 +303,20 @@ bool matrix_post_scan_qf(void) {
                  NVIC_SystemReset();
             }
         }
+        matrix_row_t remote_before[ROWS_PER_HAND];
+        memcpy(remote_before, matrix + thatHand, sizeof(remote_before));
+
         transport_slave(matrix + thatHand, matrix + thisHand);
 
+        if (memcmp(remote_before, matrix + thatHand, sizeof(remote_before)) != 0) {
+            changed = true;
+        }
+
         matrix_slave_scan_kb();
     }
 
+    matrix_scan_kb();
+
     return changed;
 }
 

corne/firmware/patches/vial-qmk-math-py.patch

@@ -0,0 +1,15 @@
+--- a/lib/python/qmk/math.py
++++ b/lib/python/qmk/math.py
+@@ -23,8 +23,10 @@ def compute(expr):
+ 
+ 
+ def _eval(node):
+-    if isinstance(node, ast.Num):  # <number>
+-        return node.n
++    if isinstance(node, ast.Constant) and isinstance(node.value, (int, float, complex)):
++        return node.value
++    elif isinstance(node, ast.Num):  # <number> (Python <3.14)
++        return node.n
+     elif isinstance(node, ast.BinOp):  # <left> <operator> <right>
+         return operators[type(node.op)](_eval(node.left), _eval(node.right))
+     elif isinstance(node, ast.UnaryOp):  # <operator> <operand> e.g., -1

corne/firmware/post_rules.mk

@@ -0,0 +1,3 @@
+# Fallback when qmk info parsing fails (e.g. Python 3.14+ ast.Num removal).
+MCU ?= STM32F401
+PLATFORM_KEY ?= chibios

corne/firmware/readme.md

@@ -5,7 +5,8 @@ Keyboard target: `sh01/m36:via`
 ## Prerequisites
 
 1. Install [QMK CLI 1.2.0](https://docs.qmk.fm/#/cli) (or QMK MSYS on Windows).
-2. Clone vial-qmk at the IFKB-pinned commit:
+2. Use **Python 3.11 or 3.12** for the build. Python 3.14 breaks the pinned vial-qmk commit unless patched (see Troubleshooting).
+3. Clone vial-qmk at the IFKB-pinned commit:
 
 ```bash
 git clone https://github.com/vial-kb/vial-qmk.git
@@ -25,6 +26,13 @@ cp -r /path/to/kb-layouts/corne/firmware/* keyboards/sh01/m36/
 
 The make target comes from that path: `keyboards/sh01/m36` → `sh01/m36:via`.
 
+If you are on Python 3.14+, apply the QMK math patch from inside your vial-qmk checkout:
+
+```bash
+cd /path/to/vial-qmk
+patch -p1 < /path/to/kb-layouts/corne/firmware/patches/vial-qmk-math-py.patch
+```
+
 ## Build
 
 ```bash
@@ -47,11 +55,25 @@ After flashing, load `../corne.vil` in Vial to restore your keymap.
 
 ## RGB brightness dial
 
-Brightness step size is controlled in `config.h`:
+Brightness step size is set in `info.json` under `rgb_matrix.val_steps` (currently `1`).
 
-```c
+With `max_brightness: 50`, step `1` gives 51 brightness levels. Increase to `2` or `4` if the dial feels too slow.
-#define RGB_MATRIX_VAL_STEP 1
-```
 
-With `max_brightness: 50` in `info.json`, step `1` gives 51 brightness levels.
+Do not also define `RGB_MATRIX_VAL_STEP` in `config.h` — QMK warns when both are set.
-Increase to `2` or `4` if the dial feels too slow.
+
+## Troubleshooting
+
+### `AttributeError: module 'ast' has no attribute 'Num'`
+
+The pinned vial-qmk commit uses `ast.Num`, which was removed in Python 3.14. Fix options:
+
+1. **Recommended:** build with Python 3.11 or 3.12 (`python3.12 -m venv .venv && source .venv/bin/activate && pip install qmk`).
+2. **Alternative:** apply `patches/vial-qmk-math-py.patch` inside your vial-qmk checkout (see Install step above).
+
+### `Platform not defined`
+
+Usually a follow-on error from the `ast.Num` failure — QMK never parses `processor: STM32F401` from `info.json`. Fixing the Python issue should resolve this. `post_rules.mk` also provides a fallback (`PLATFORM_KEY = chibios`, `MCU = STM32F401`).
+
+### `RGB_MATRIX_VAL_STEP in config.h is overwriting rgb_matrix.val_steps in info.json`
+
+Keep the step size in **one place only** — use `val_steps` in `info.json`, not `#define RGB_MATRIX_VAL_STEP` in `config.h`.

corne/firmware/rules.mk

@@ -24,5 +24,6 @@ SRC += rtt_viewer/SEGGER_RTT.c
 
 CUSTOM_MATRIX = lite
 SRC += matrix.c
+SRC += m57.c
 # SRC += split_util_qf.c
 ALLOW_WARNINGS = yes

corne/firmware/split_util_qf.c

@@ -183,8 +183,7 @@ bool is_keyboard_master_impl(void) {
 }
 
 bool is_keyboard_left(void) {
-    // return split_config.left;
+    return split_config.left;
-    return false;
 }
 
 bool is_keyboard_master(void) {