Arduino to AtTiny change of pin interrupt behaviour?
After going through a lot of documentation, it seemed best and more efficient to attach the interrupt without functions.
EIMSK  |=  (1&lt;&lt; INT0);//Attaches the interrupt
MCUCR  |=  (1&lt;&lt; SM1)  //Power-down mode
         | (1&lt;&lt;ISC01) //The rising edge of INT0
         | (1&lt;&lt;ISC00);// generates an interrupt request