Use of arduino libraries for pin --> interrupt

[thigger]

LwRx was trying to use the wrong interrupt on my Pro Micro (32u4, like Arduino Leonardo). There's a function in the standard libraries to translate pins to interrupts so I've just bunged in this as a replacement for getIntNo and it works like a charm.

Thanks for the library BTW!

/**
   Get Int Number for a Pin
**/
int getIntNo(int pin) {

    return  digitalPinToInterrupt(pin);

}

[roberttidey]

Thanks. That's much cleaner. I have made that change in the repository.