AnsweredAssumed Answered

USB CDC problem

Question asked by JanTM on Mar 2, 2016
Latest reply on Mar 4, 2016 by JanTM
I am using the Stm32CubeL4 to generate a USB device with a CDC class. This is on a custom board. I am not using the USB ID line or VBUS.

It runs, but USBD_CDC_Init() is never called.

On the Windows side, I see an "unknown device"  with message "Windows has stopped this device because it has reported problems. (Code 43)". All driver items are marked as unknown. I tried upgrading the driver it said none found. 

I installed stsw_stm32102 the Virtual Com driver but the problem continues.

I suspect there is a low level USB problem that occurs prior to getting the VID/DID, I have not seen the USB become addressed yet.

I have not added any code to send or receive data over the port yet or to handle any events.

I also bumped the heap size to 400 to no avail. 

Is there a way to debug the USB interface with Windows and find the cause of the problem?