GitHub

AttachInterrupt for all pins of Arduino Uno, Nano, Mini and other 328-based boards.

This is an Arduino library that enables you attach an interrupt to any pin of Arduino Uno, Nano, Mini and other 328-based boards. The Arduino attachInterrupt() function only allows pines 2 & ~3.
GitHub

attachInterrupt does not work on GPIO27

volatile uint32_t CNT; void setup(){ Serial.begin(115200); attachInterrupt(digitalPinToInterrupt(27), ISR_func, RISING); //or attachInterrupt(27, ISR_func, RISING ...