Merge remote-tracking branch 'upstream/master'

* upstream/master: (1239 commits)
  Update ez.c
  removes planck/rev3 temporarily
  Move hand_swap_config to ez.c, removes error for infinity
  Update Makefile
  ergodox: Update algernon's keymap to v1.9
  Added VS Code dir to .gitignore
  Support the Pegasus Hoof controller.
  [Jack & Erez] Simplifies and documents TO
  add readme
  use wait_ms instead of _delay_ms
  add messenger
  init keymap
  Add example keymap
  Adding whiskey_tango_foxtrot_capslock ergodox keymap
  Unicode map framework. Allow unicode up to 0xFFFFF using separate mapping table
  CIE 1931 dim curve
  Apply the dim curve to the RGB output
  Update the Cluecard readme files
  Tune snake and knight intervals for Cluecard
  Tunable RGB light intervals
  ...

1 files changed, 26 insertions, 0 deletions

diff --git a/keyboards/lets_split/serial.h b/keyboards/lets_split/serial.h
new file mode 100644
index 000000000..15fe4db7b
--- /dev/null
+++ b/keyboards/lets_split/serial.h
@@ -0,0 +1,26 @@
+#ifndef MY_SERIAL_H
+#define MY_SERIAL_H
+
+#include "config.h"
+#include <stdbool.h>
+
+/* TODO:  some defines for interrupt setup */
+#define SERIAL_PIN_DDR DDRD
+#define SERIAL_PIN_PORT PORTD
+#define SERIAL_PIN_INPUT PIND
+#define SERIAL_PIN_MASK _BV(PD0)
+#define SERIAL_PIN_INTERRUPT INT0_vect
+
+#define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
+#define SERIAL_MASTER_BUFFER_LENGTH 1
+
+// Buffers for master - slave communication
+extern volatile uint8_t serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH];
+extern volatile uint8_t serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH];
+
+void serial_master_init(void);
+void serial_slave_init(void);
+int serial_update_buffers(void);
+bool serial_slave_data_corrupt(void);
+
+#endif