Make the CPU and board selection part of sketch configuration. #11151
Description
I want to save the board type & CPU variant with a particular sketch - the hardware determines a wide variety of sketch code decisions and I have almost invariably chosen a particular CPU+PCB layout for my projects and kept it throughout development.
When I move between computers I often forget about this setting and in some cases only discovered the problem after many hours of debugging device communications on the uploaded sketch..... Only to find that TTL comms are broken due to clock calculation issues from incorrect CPU type setting. This wasted a lot of time for me, more than once.