My win7 system, why can't I find the serial port of the MCU development board burning program? Is this the case?
Right-click my computer properties hardware device manager to find the port, and see if your microcontroller serial port corresponds correctly. If the correspondence is correct, it can be adjusted. If the correspondence is correct, you can see if the serial port of your serial port debugging assistant is closed. If it is open, it should be these two situations.