Nick Marsh

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8 years, 5 months ago.

How to access a declared Usart1 from another cpp file ?

I guess that I must place an extern declaration in the new.cpp file,

but I cant find any syntax that shows me how to do it :(

1 Answer

Andy A
8 years, 5 months ago.

file1:

Serial pc(USB_TX,USB_RX);

file 2:

extern Serial pc;

Or you can put the extern command in a header file that you then include in everything. For a single serial port this isn't worth it but if you have lots of variables or objects you want to be visible in two files then it makes things easier. globals.h:

extern Serial pc;

file1.cpp:

#include "globals.h"
Serial pc(USB_TX,USB_RX);

file2.cpp:

#include "globals.h"