The USB HOST CDC class test questions from the STM32F411 Discovery Board.

[Jong-il Lee]

​

Hello, I’m porting USB HOST CDC function on stm32f411 discovery board, but it is not working.

​Test environment. I connect the STM32F411 Discovery Board and CH340 USB serial Module, and send it repeatedly about 100 bytes in 5 sec.

​​Test procedure. 1. USB Host_Only, Communication Host Class setting in CUBEMX.

​

​2. After download, when I connect the USB serial module, the message "USB Device Attached" is printed and "USB Device disconnected" is printed when removed.

​

​3. After HOST_DEV_ATTACHED on USBH_Process(), ENUMERATION does not work.("Enumeration done.“ message isn’t printed)

​4. No voltage is applied to the VBUS signal.

​

​

​Please tell me how to solve this problem.

​

​