Integration of google analytics with codeignitor application using HelloAnalytics

Hello,I have a requirement to integrate google analytics API with the code which is in PHP Codeignitor. I am able to get the data from google analytics separately but not able to integrate it with my PHP code.I want to get the google analytics class in my Controller pass date to the particular method present in google analytics class and get data according to those dates in the array format as well as i want to pass that array values to excel file which is generated using PHPExcel. I am referring HelloAnalytics for getting "google Analytics data".Please let me know if anyone is having idea about how to integrate it