Available external interrupts

[mfreema5]

I had difficulty tracking down information on which pins can be used with attachInterrupt(), so I thought I'd share what I found. Hopefully it's useful to someone.

Board PIN	Internal PIN	Interrupt
A2	16	EXTERNAL_INT_0
A3	17	EXTERNAL_INT_1
A6	20	EXTERNAL_INT_4
A7	21	EXTERNAL_INT_5
D2	2	EXTERNAL_INT_2
D3	3	EXTERNAL_INT_3
D9	9	EXTERNAL_INT_9
D10	10	EXTERNAL_INT_10
D11	11	EXTERNAL_INT_11

That information was extracted from github.com/arduino/ArduinoCore-samd/blob/master/variants/nano_33_iot/variant.cpp. Use at your own risk, etc.

Edit: Trials show the analog pins don't seem to work as interrupts.

[ostaquet]

Thanks, very useful!

Added in the doc ;-)

[mfreema5]

So, it seems I wasn't reading the information on github.com/arduino/ArduinoCore-samd/blob/master/variants/nano_33_iot/variant.cpp quite right. Turns out you need to look at the column labeled Peri.A EIC (EXTINT); entries with an asterisk (*) are available as interrupts.

Corrected table:

Board PIN	Internal PIN
A1	15
A5	19
A7	21
D2	2
D3	3
D9	9
D10	10
D11	11

I've tested all these and they do act as interrupts. (At least they do in a simple sketch that does nothing but detect interrupts.)

[ostaquet]

Thanks for the update ;-)