Interrupts not fully documented

[nickgammon]

The reference page for attachInterrupt is below:

http://arduino.cc/en/Reference/AttachInterrupt

It does not mention the use of ISR(whatever) to implement interrupts other than the external interrupts. It mentions:

a function to call when an external interrupt occurs

This implies that there are also internal interrupts, however there is no documentation about how to use them. A mention of ISR, or another page describing it, would be helpful.

Also attachInterrupt does not mention the trap that, if a particular event is pending (eg. an external interrupt) then the interrupt fires the moment that the attachInterrupt is done. This may confuse people who expect that only future interrupts will be processed.

I have extensive documention about Arduino interrupts here:

http://www.gammon.com.au/interrupts

I would be happy to help with improving the reference documentation.

[shfitz]

Added some information about ISRs and added a link to Nick's notes for more information.