pert:
This is very annoying. On GitHub - vorpalrobotics/VorpalHexapod: Arduino code for both the Vorpal Hexapod and Vorpal Hexapod Gamepad. it says:but I find no mention of the libraries anywhere in their wiki.
Interestingly enough going to the above github page gives you these three links
Main Hexapod Page: Vorpal The Hexapod - Vorpal Robotics Wiki Assembly Instructions: Vorpal The Hexapod Assembly Instructions - Vorpal Robotics Wiki Arduino Libraries and other files: Vorpal Hexapod Source Files - Vorpal Robotics Wiki
The last one of which takes you to the wiki page dealing with the source code and libraries.
On that page there is this link to a dropbox page
The latest stable release source plus a copy of all required libraries and some other useful files are on our source support dropbox page: Vorpal Hexapod Source Support Files
This page contains a sub-directory named libraries which contains two zip files:-
- Adafruit-PWM-Servo-Driver-Library-master.zip
- arduino_pixy-0.1.7.zip
Not exactly difficult to find if you read the wiki pages. Much better documentation than a lot of other projects posted on the web. Try finding the "correct" library for a source file containing:-
#include <DS3231.h>
All the libraries seem to be called DS3231 and they are all very different. 
Ian