USB with 3 virtual com ports in 1 physical Connection

[SBaum.1]

Hello, i try to get USB working with the EG91 Modul from Quectel. Is there anywhere a tutorial what steps are to do? Ive read the USB Host Documentation but my device is still in Application idle Mode.

Im using the USB_Host Driver and the CDC Middleware driver.

There are 3 virtual Com Ports in the GSM Modul.

 MX_USB_HOST_Init(); and MX_USB_HOST_Process(); are called

[Pavel A.]

So you need to implement USB host working with a multi-functional device.

Read the descriptors, find and configure all endpoints for the 3 CDC functions, then drive all needed endpoints (read and write).

Maybe start from driving one function, then add others.

ST does not provide complete example for this; you may want to get a good, commercial USB library, or find a consultant.

-- pa