overflow in implicit constant conversion [-Woverflow]
if(IRcode = 0xFF30CF){
^
I input a code and there is a warning as above, please immediately I ask for his advice, thank you
If you can't assign 0xFF30CF to IRcode, without a "overflow in implicit constant conversion" warning, then clearly IRcode can't hold that value, so changing the = to == will still NOT produce meaningful results, as the test will never be true.
I suggest that you take your snippets to snippets-r-us where they have crystal balls. Mine are brass.