I'm writing a custom library and it is working correctly on an Arduino Uno. However I've now got my hands on an Arduino Due and I need to define some board specific pin constants. 

I know for most boards you can do this through an `#ifdef` directive using the IO constants defined in `\\arduino-1.5.2\hardware\tools\avr\avr\include\avr\io.h`. For instance:

```
#if defined (__AVR_ATmega128__)
    //do something specific
#endif

```

Does anybody know which is the correct constant to use for the Due?