STM32F47VITX6 USB identifies but does not send data

[lbrendel]

I have an STM32F4227 that identifies its USB port to a host PC and all information looks correct but no data is sent or received. Looking with the debugger the microcontroller is running task scheduler but does not recognize messages being sent.

Is there a register i should be looking at to determine if the USB interface is indeed operating correctly? That it would identify itself but not be able to detect any messages?

[TDK]

There is no dummy light or indicator that says everything is working correctly. I suggest following from an existing example or posting and debugging the code you are working with and providing more information about your use case--what you expect to happen vs what actually happens.

??

Also be aware some terminal programs may buffer until they get or need to send a newline.

[lbrendel]

Apologies on the label, I corrected that. I should also clarify that the code I am using has worked on hundreds of other units already. Essentially when i plug in the USB of my unit to a PC and provide power, Windows recognizes the device and shows up in Device Manager with all of the correct information, to me that would point to a successful data connection. The USB lines feed directly to the micro. But if i then use a terminal connection on the PC to send a message the microcontroller never detects that a message was received. Using same serial settings as all other units.

Even if all serial settings are the same and repeated across all units and all units identify themselves is there a register or setting or event of the USB peripheral that would cause it to not accept/detect a message but appear to be active? Is there an internal disconnect from the peripheral recognition to the data transmission?

[FBL]

Hi @lbrendel 

Did you check STM32CubeF4 examples? Check examples implementing CDC ACM.