I have been porting my .Net MF code ofer to the Arduino ProMicro 5v/16MHz and finaly got the code to do something today.
The arduino IDE is really bad if you're used to using Microsoft's Visual Studio. This process was made allot easier once I set Visual Studio up to create Arduino projects using Visual Micro.
Turns out though that the main problem was in the firmware I had written, as detailed in my post entitled "Arduino Pro Micro: how to access A1" at http://electronics.stackexchange.com/.
My arduino interface board still has a couple of buggs and requires one bodge wire which I have identified so far, but here it is:
Once I get this thing flying, I'll upload the Eagle files here.
This is proving to be a slow and painfull process.