I was trying to get an outfit I know interested in this board, but that did not happen. I combined my RPUpi shield and an ATmega324pb for the application program. The combination worked, but I had a few hardware bugs to sort out, so another revision was needed. For this board, I started software development with the SelfTest first to help find the problems. I suspect it speeds up hardware development. I only worked on the library (core) parts that were part of testing.