The original nano uses a dedicated purpose FT232RL USB to Serial chip instead of the general purpose SAMD11D14 micro chip. AFAIK, there is no custom firmware for the FT232RL and I don't find any reference in the datasheet for how it adapts to serial parameter changes. So my guess is the FT232RL will change immediately with any USB descriptor changes. Where as, the SAMD11 needs a DTR trigger. However, the FT232RL does store some configuration data in an on-board eeprom. FTDI has a tool available to customize the eeprom values, https://www.ftdichip.com/Support/Utilities.htm#FT_PROG but again, I do not see any reference to serial port speed. As such, it seems odd that the original nano suffers the same malady.
For the nano every, you could change the default baud rate in the firmware source, recompile and reprogram the SAMD11.
On 1/6/21 8:31 PM, Dean Souleles wrote: