Hi...first, sorry for my english...
I am trying to use these pins: 33, 31, 35 , as interrupts pins, but i can't do it.. i am using library "PinChangeInt" , mega 2560, but it doesn't work... i don't know how to do that those pins (i am connecting a encoder there) get function with interrupts... could somebody help me? 
Do not cross-post. Other thread removed.
Those pins come from Port C, which does not support PCINTs.
CrossRoads:
Those pins come from Port C, which does not support PCINTs.
Thanks... but i know that in a firmware (Marlin) use this pins for to control the encoder of full graphic smart controller, using arduino mega 2560, remps 1.4, and the full graphic smart controller; but i dont know how Marlin do it
Without a schematic, we don't either. Maybe the code for that just reads the pins really fast?