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SBaum.1
SBaum.1
Visitor II
March 27, 2020
Question

USB with 3 virtual com ports in 1 physical Connection

  • March 27, 2020
  • 1 reply
  • 590 views

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

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1 reply

Pavel A.
Pavel A.
March 27, 2020

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

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