Use SAMD21 instead of SAMD11
The SAMD11 is a bit too constraining when it comes to computing the PLL parameters / register values for the Si5351C. Let's upgrade to a SAMD21 to get more flash + RAM.
- Status changed from Stalled to In Progress
- % Done changed from 10 to 30
SAM D21E inserted, proper supply connections ongoing. UEXT UART is now different from the one on the debug header (UEXT on SERCOM1; 2.5mm jack and TagConnect UART on SERCOM3) - I think we must go on with a 4-layer-PCB, given the requested features #3858 and esp. #3857. #3905 only needs more PCB space and a header but must follow the other tasks, as the pins needed for #3857 have priority.