I2C slave support for Feather M4

Author: JordanMajd

variants/feather_m4/variant.h

@@ -157,6 +157,10 @@ static const uint8_t SCK  = PIN_SPI_SCK ;
 #define PIN_WIRE_SCL         (22u)
 #define PERIPH_WIRE          sercom2
 #define WIRE_IT_HANDLER      SERCOM2_Handler
+#define WIRE_IT_HANDLER_0    SERCOM2_0_Handler
+#define WIRE_IT_HANDLER_1    SERCOM2_1_Handler
+#define WIRE_IT_HANDLER_2    SERCOM2_2_Handler
+#define WIRE_IT_HANDLER_3    SERCOM2_3_Handler
 
 static const uint8_t SDA = PIN_WIRE_SDA;
 static const uint8_t SCL = PIN_WIRE_SCL;