-#define serNO_PARITY ( ( unsigned portCHAR ) 0x02 << 3 )\r
-#define ser8DATA_BITS ( ( unsigned portCHAR ) 0x03 )\r
-#define ser1STOP_BIT ( ( unsigned portCHAR ) 0x07 )\r
-#define serSYSTEM_CLOCK ( ( unsigned portCHAR ) 0xdd )\r
-#define serTX_ENABLE ( ( unsigned portCHAR ) 0x04 )\r
-#define serRX_ENABLE ( ( unsigned portCHAR ) 0x01 )\r
-#define serTX_INT ( ( unsigned portCHAR ) 0x01 )\r
-#define serRX_INT ( ( unsigned portCHAR ) 0x02 )\r
+#define serNO_PARITY ( ( unsigned char ) 0x02 << 3 )\r
+#define ser8DATA_BITS ( ( unsigned char ) 0x03 )\r
+#define ser1STOP_BIT ( ( unsigned char ) 0x07 )\r
+#define serSYSTEM_CLOCK ( ( unsigned char ) 0xdd )\r
+#define serTX_ENABLE ( ( unsigned char ) 0x04 )\r
+#define serRX_ENABLE ( ( unsigned char ) 0x01 )\r
+#define serTX_INT ( ( unsigned char ) 0x01 )\r
+#define serRX_INT ( ( unsigned char ) 0x02 )\r