EMBO does USB (not mentioned in README.md)

[msalat]

These boards seem to support USB with EMBO:

STM32F103C8
STM32F103RE
STM32F303RE
STM32F401CC
STM32G431KB
STM32L412KB

I've tested STM32F303RE with PA11 (USB_DM) & PA12 (USB_DP) (PA12 with 1.5 kOhm pullup to 3.3 V).
→ much faster sample transfer to PC, USB "Serial Port" has no "baud rate" like physical serial ports.

→ individual setting of baud rate would be nice. Perhaps initial communication with 115200 baud and then change speed?

[msalat]

PS1: build instructions would be nice.
PS2: to compile using actual stm32cube, you have to set -fcommon, otherwise there will be an error with GCC11 and later (or use extern or static or whatever).