CH32F103C8T6 chip is compatible with STM32F103C8T6 series chips, all pins are compatible, all registers
are compatible, but the USB function is enhanced. There are 2 USBs, one HOST, and one Device, which
have stronger functions and lower cost. However, the flash download algorithm is different from the
compatibility of internal BootLoader and st company. ST's download software cannot be used, but the
official software download is also very convenient. You can use both serial port and USB methods.
The USB method is faster and is not required. Develop additional BootLoader.