UnoDueTre:
As regards your sketch not working at 115200, could it be that at 20MHz there is no division ratio that will generate that baudrate closely enough?
Looks like 230400 is the only bad choice...
http://www.wormfood.net/avrbaudcalc.php
UnoDueTre:
As regards your sketch not working at 115200, could it be that at 20MHz there is no division ratio that will generate that baudrate closely enough?
Looks like 230400 is the only bad choice...
http://www.wormfood.net/avrbaudcalc.php