Using functions in header files I want to include a function in my sketch I moved to a .h file.
I did it as follows:
My code:
#include &quot;header.h&quot;

void setup() {
  fct();
}

void loop() {

}

My header:
#include &quot;Arduino.h&quot;
#ifndef MYHELPERS_H
#define MYHELPERS_H

void fct() {
// stuff
}

#endif

The same process seems to work for variables but the IDE says this function in not declared in this scope...
I don't understand what I'm doing wrong...
Thanks guys!
I found a solution somewhere else on internet...
This portion:
#ifndef MYHELPERS_H
#define MYHELPERS_H

Was not written correctly... &quot;MYHELPERS_H&quot; should've been replaced by the name of my file. Now it works just fine.