C++ Namespace/scope problem when trying to attach arduino interrupt
You can't.

Simply because a class member is not the right format of function for attachInterrupt.

You can only use normal functions with attachInterrupt, so the normal method is to have a normal function outside your class which then calls the member function within your class.  How you arrange it so that it knows where your objects are is up to you.


If you have only one object then assign it to a global pointer in your library using the constructor
If you have lots of instances then create a linked list within your class in a static context and add each object to it in the constructor, then iterate through that list when the interrupt fires.