USB CDC device on STM32F042 getting ''Device Descriptor Request Failed''

[Henrik Sandaker Palm]

Posted on January 07, 2017 at 23:15

I'm struggling getting a STM32F042G6 to enumerate as CDC device. I'm getting the Device Descriptor Request Failed in device manager. Did it enumerate right away with only CubeMX generated code for you? I'm running the mcu crystal-less, tried both with and without 1.5K pullup on D+ and 22R series termination resistors. just trying my luck here, thinking I'm about to start my own thread soon.

[Imen.D]

Posted on January 09, 2017 at 12:37

Dear

Sandaker_Palm.He

‌, Please, avoid mixing new discussion in the many old threads (

https://community.st.com/0D50X00009XkeGNSAZ

,

https://community.st.com/0D50X00009Xkfy0SAB

,

https://community.st.com/0D50X00009XkftBSAR

) and creating a new one for your issue, this will be more easy for user forum.

What is the OS version of you computer (windows 8? 10 .. )?Which version of CubeMx are you using ?

You may use and get inspired from working CDC example available in the STM32CubeF0 firmware packageto identify what is going wrong in your case and confirm if the problem here seems related to the hardware or software environment:

STM32Cube_FW_F0_V1.7.0\Projects\STM32072B_EVAL\Applications\USB_Device\CDC_Standalone

Best Regards

Imen

[Henrik Sandaker Palm]

Posted on January 09, 2017 at 13:27

Dear Imen,

Yes, I'm aware what I did. Sometimes when you know of someone that has accomplished what you also need to accomplish, you feel like asking the person directly, instead of putting an ad in the newspaper and hoping that the person will see it and reply. But I will try to contain myself in the future.

I was about to start my own thread actually when I for one last time decided to check the actual hardware. I had switched D+ and D- in belief the could be wired directly to a PCB mount USB A male connector. This is actually something I have double checked twice before. They can be wired directly, if the USB connector is mounted from the bottom . Or else they have to cross each other. Which I now have done and my hardware enumerates just fine!

[Imen.D]

Posted on January 09, 2017 at 16:05

Hi

Sandaker_Palm.He

‌,

It's a great pleasure to know that you have enumerates your hardware .

Thanks for your contribution and a

ll your feedback are welcome.

Best Regards

Imen