Everything is explained in the README files inside the directories:
include/README:
This directory is intended for project header files.
A header file is a file containing C declarations and macro definitions
to be shared between several project source files. You request the use of a
header file in your project source file (C, C++, etc) located in src folder
by including it, with the C preprocessing directive `#include’.
#include "header.h"
int main (void)
{
...
}
Including a header file produces the same results as copying the header file
into each source file that needs it. Such copying would be time-consuming
and error-prone. With a header file, the related declarations appear
in only one place. If they need to be changed, they can be changed in one
place, and programs that include the header file will automatically use the
new version when next recompiled. The header file eliminates the labor of
finding and changing all the copies as well as the risk that a failure to
find one copy will result in inconsistencies within a program.
In C, the convention is to give header files names that end with `.h’.
Read more about using header files in official GCC documentation:
- Include Syntax
- Include Operation
- Once-Only Headers
- Computed Includes
Header Files (The C Preprocessor)
Note: This is about project header files. So instad having your projects header files in the src directory, you can place them into the include directory.
.
├── include
│ ├── file1.h
│ ├── file2.h
│ ├── file3.h
├── lib
├── src
│ ├── file1.cpp
│ ├── file2.cpp
│ └── file3.cpp
├── test
└── platformio.ini
lib/README:
This directory is intended for project specific (private) libraries.
PlatformIO will compile them to static libraries and link into the executable file.
The source code of each library should be placed in a separate directory
(“lib/your_library_name/[Code]”).
For example, see the structure of the following example libraries Foo and Bar:
.
├── lib
│ ├── Bar
│ │ ├── doc
│ │ ├── examples
│ │ ├── src
│ │ │ ├── Bar.cpp
│ │ │ └── Bar.h
│ │ └── library.json (optional. for custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
│ ├── Foo
│ │ ├── Foo.c
│ │ └── Foo.h
│ └── README --> THIS FILE
├── platformio.ini
├── src
│ └── main.c
Example contents of src/main.c using Foo and Bar:
#include <Foo.h>
#include <Bar.h>
int main (void)
{
...
}
The PlatformIO Library Dependency Finder will find automatically dependent
libraries by scanning project source files.
More information about PlatformIO Library Dependency Finder
