AnsweredAssumed Answered

USB OTG CDC Device busy when trying to send

Question asked by Moll.Benjamin on Sep 17, 2016
Latest reply on Oct 26, 2016 by FTITI.Walid
hey guys,

so I am using an STM32F411 as an USB device. It's connected via VCOM to a PC. I am using HAL V2.4.1 from 19-June-2015. 
In general it works good, but when I quickly connect and disconnect the usb plug on the device for a few times in a row and then re-connect with my terminal PC tool the device is no longer sending data because
USBD_CDC_TransmitPacket
 returns USBD_BUSY only!

I have no idea how handle this case. Should I somehow reset the USB driver? Is this an indication that s/t is messed up with my implementation? Why is it busy? What can cause such a state?

Any help is appreciated. Let me know if you need more information on this.

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