Github is a code-sharing website where we keep all the most up-to-date code associated with Public Sensors. If you are using a Public Sensors sensor kit, all the files you need are likely already loaded on your microcontroller. If you deleted any file by accident, you can download them from out GitHub site.
If you assembled your own kit, you will need to load all the necessary code files on to your microcontroller yourself.
Access the Public Sensors github page here:
https://github.com/publicsensors
From the GitHub homepage, you can navigate into the folder, technically called a repository, called MicrocontrollerKits to find all the code needed for activity modules.