Aiming to migrate working sketches from UNO R3 to UNO R4 Wifi board - however including the NMRADCC library in an R4 sketch generates the below error (even if it is ...

An Atmega328 sketch using an added .cpp file with attachInterrupt(....) and detachInterrupt(...) statements compiles successfully in the Arduino IDE 1.8.6 with no errors. However the same sketch gives ...