CODEWITHSUNDEEP
c-preprocessormicrochip
Ron Vaisman
Ron Vaisman

Reputation: 169

#define scope (microchip studio)

Im using microchip studio How can I define F_CPU in main.c file and make all files "see" this definition?

I declared in main.c:

#include <avr/io.h>
#include "UART.h"
#define F_CPU 12000000

and in UART.c I tried using this definition :

        ubrr_value = (F_CPU/(2*BAUD_RATE))-1;

i recieved this error:

Severity    Code    Description Project File    Line

Error 'F_CPU' undeclared (first use in this function) UART_TEST XX\UART_TEST\UART_TEST\UART.c 55

Upvotes: 2

Views: 312

Answers (1)

KamilCuk
KamilCuk

Reputation: 141768

How can I define F_CPU in main.c file and make all files "see" this definition?

You can't.

You can define F_CPU in your compiler command line arguments. For example gcc compiler takes -DF_CPU=12000000. And compile all your sources with that definition.

You can refactor your code, and put F_CPU into separate file and include it from all files that need it.

// config.h
#deifne F_CPU 12000000

// main.c
#include "config.h"

// uart.c
#include "config.h"
...
        ubrr_value = (F_CPU/(2*BAUD_RATE))-1;
...

Upvotes: 1

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