We used code from Rob Tillaart. Orginally, he didn't have the library in it's own repo, which made it difficult to clone directly into the Arduino libraries folder, so we reorganized things a bit. He has since then reorganized his repos so the AD5242 is in it's own repo. We'll probably deprecate this repo in a few months, but it's currently being used in various systems we've already deployed and we're afraid of breaking our code by changing things up now. Anyway, all credit goes to Rob and his work on this library.
See his new repo here: https://github.com/RobTillaart/AD524X