I post this here in case this information helps people from spending too much time debugging their promega 2560.
Issues with reading pin A8 and others.
I use this small board in some of my projects. I purchased some more in case I needed some in the future and put them away on the shelf.
I needed to replace one of my existing promega 2560s and put one of the new ones in its place. Pin A8 would not read in neither analog nor digital. A quick check showed other some pins not working either. I tried another of the new batch and it was the same.
I tried a "normal" 2560 and it worked.
I read elsewhere on the internet that some people are having, or have had, issues as well which could be related to this same problem.
As the original promega 2560s worked and these don't I suspect the board/chip itself but I am open to the possibility that the IDE is a bit confused by these new ones (although I can't see how it would know which was plugged in).
Cheers Alan