How to call Serial.print() from .c file in Arduino IDE?

Question

I have two files in Arduino IDE. One is the .ino file and one is a .c file.

main.ino:

#include "somefile.c"

void setup(){
    Serial.begin(9600);
    // Do something
}

void loop(){
    // Do something
}

And in somefile.c I want to call Serial.print(). How can I do that? Thanks!

Answer 1

create a my_logging.h file with

void my_log(const char *msg);

create a my_logging.cpp file with

#include <Arduino.h>
extern "C" {
  #include "my_logging.h"
}

void my_log(const char *msg) {
  Serial.println(msg);
}

then in in your c file include the my_logging.h file and you can use the my_log function