Type: DirPath | Multiple: No | Default: “<Project>/boards

The location of project-specific board definitions. Each project may choose a suitable directory name. The default value is boards, meaning a “boards” directory located in the root of the project.

By default, PlatformIO looks for boards in this order:

  1. Project boards_dir (as defined by this setting)

  2. Global core_dir/boards

  3. Development platform core_dir/platforms/*/boards.

This option can also be configured by the global environment variable PLATFORMIO_BOARDS_DIR.