I think that this could be covered in the book that one of the other posters was looking at writing. I still class myself a s a PBP newbee, and yesterday I used the LCDOUT command to write to a 2 x 16 LCD for the first time. I used a different port, but following the excellent diagram, and using the sample code in the manual it worked 1st time But other commands and how they function are very sparce in their description on how they finction, or have no examples on their use.

I've not dabbled with USB, so I can't really comment on your project or the problems you've experienced, but maybe you could post an article in the documentation section for future reference for others. At least this would help others until such time that the manual is re-vamped