ESP8266 Community Forum

Please close. Solution is to add
void ICACHE_RAM_ATTR handleInterrupt();
instead of
#define ICACHE_RAM_ATTR

to the top. It is working fine with this change. There will be this issue with guidelines written for board library 2.5.0.

Thank you

Yes. The interrupt routine must be declared before the code that references it.

You can either add the declaration as you have done or you can just move the body of the actual isr routine above the code that references it.

I confirm adding
void ICACHE_RAM_ATTR handleInterrupt();
to the top solved the problem on ESP8266. Can close, thank you.