Ok, I saw a video on building an emulation station using an ultimark ipac2 with the raspberry pie.  I have used a ipac before using mame on a PC. This video seemed to show the ipac being plug and play, but it sure isn’t.  I have done numerous searches here and google and have watched numerous videos, but none seem to cover the ipac2.  I have went through the pi and updated everything and ran all the set ups, but when I configure the controller in retro arch, nothing works.  Half of the buttons don’t even register.  Now I assume I can edit a config file, but that is beyond my level without some help.  
Can anyone please put me in the right direction?  I am desperate.