Inside CentrosController at the end ...
public function createPdfAction() {
global $config;
$loader = new \Phalcon\Loader();
$loader->registerDirs(
array(
$config->application->libraryDir."fpdf/"
)
);
echo $config->application->libraryDir."fpdf/"; // this is Ok.
$loader->register();
$pdf = new FPDF();
}
PHP Error .>Fatal error: Class 'FPDF' not found in C:\wamp\www\ph_rosaleda\app\controllers\CentrosController.php on line 253