Does there exist a software serial library that works on microcontrollers without PCINT? The ATmega64 and ATmega128 have 8 “general” interrupt pins, but no PCINT.
My Yet Another Software Serial (written for an Uno) uses the external interrupts. Maybe it could be adapted to meet your requirement.
Or change to a compatible device that does have PCINTs, like the Atmega1281 or 2561.
CrossRoads: Or change to a compatible device that does have PCINTs, like the Atmega1281 or 2561.
No, that's not an option. The ATmega64/128 are much cheaper, and should fit most applications where 4kb of RAM