Why does it need to be broken up into multiple files?
You can have two pde files in one sketch directory. Opening the sketch will open both pde files, in separate tabs. You can put functions in one pde file, and call them from the other pde file.
I have the same question and see no useful answer here
I've broken up the project into several "libraries", which are shared with several "sketches". For instance, a RS485 library that is used by all other modules. This RS485 library now depends on a time library I created and I can't figure out how to include the time header file in the RS485 cpp file.That is, in my library directory I have, for simplicity's sake let's call it a rs485 and a time directory. Each contain their cpp and h files. The sketch contains "#include" for both time and rs485. All is happy. Now if I want to use the time class within the rs485 class, I can't find a way to include the time header in the rs485 cpp file.