Ermm, no, I am probably just using the wrong wording or worded my question unclear. Sorry for that.
Let’s try again:
On some Arduino clone I have a pullup resistor on pin 2 and this code:
attachInterrupt(0, called_on_data, RISING);
Which means that I get an interrupt when there is data on digital pin 2.
But digital pin 2 is not always interrupt 0. Not so much on Nanodes as well as on Teensy (where it is pin 7 and interrupt 2, as example).
Which brings me back to my initial question:
If I use the D2 pin on the Rainbowduino Board. Will I have to use the interrupt 0? Or is this different with the Rainbowduino v3?
And regarding the free: If some piece of code already attached a callback method on say, interrupt 0, it is not very wise to attach my own code on interrupt 0 as well. The Nanode - as example - already has an interrupt reserved (and attached) for the network interface. That example for explaining why I asked about “free”.
Regards and thanks,