Changed LED_BUILTIN to a macro to better support boards that do not have a built-in LED.

Fixes arduino#758

Author: cmaglie

hardware/arduino/variants/ethernet/pins_arduino.h

@@ -44,7 +44,7 @@ static const uint8_t SCK  = 13;
 
 static const uint8_t SDA = 18;
 static const uint8_t SCL = 19;
-static const uint8_t LED_BUILTIN = 9;
+#define LED_BUILTIN 9
 
 static const uint8_t A0 = 14;
 static const uint8_t A1 = 15;

hardware/arduino/variants/leonardo/pins_arduino.h

@@ -101,7 +101,7 @@
 
 static const uint8_t SDA = 2;
 static const uint8_t SCL = 3;
-static const uint8_t LED_BUILTIN = 13;
+#define LED_BUILTIN 13
 
 // Map SPI port to 'new' pins D14..D17
 static const uint8_t SS   = 17;

hardware/arduino/variants/mega/pins_arduino.h

@@ -39,7 +39,7 @@ static const uint8_t SCK  = 52;
 
 static const uint8_t SDA = 20;
 static const uint8_t SCL = 21;
-static const uint8_t LED_BUILTIN = 13;
+#define LED_BUILTIN 13
 
 static const uint8_t A0 = 54;
 static const uint8_t A1 = 55;
@@ -360,4 +360,4 @@ const uint8_t PROGMEM digital_pin_to_timer_PGM[] = {
 
 #endif
 
-#endif
+#endif

hardware/arduino/variants/standard/pins_arduino.h

@@ -44,7 +44,7 @@ static const uint8_t SCK  = 13;
 
 static const uint8_t SDA = 18;
 static const uint8_t SCL = 19;
-static const uint8_t LED_BUILTIN = 13;
+#define LED_BUILTIN 13
 
 static const uint8_t A0 = 14;
 static const uint8_t A1 = 15;