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Associate
Mar 12, 2025 3:34 PM UTC
Question

STM32F103RBT6 USB problem

Hello, 

I have a problem with communication between my PC and MCU. I have connected my project according to this diagram (with external 12MHz oscillator): 

radekklepal99_0-1741793253915.png

radekklepal99_0-1741794688405.pngradekklepal99_1-1741794719699.png

 

I attempted to connecting the 1,5k GPIO pin (PA10) to control the pull up. Then I connected a 1,5K resistore to 3V3.

Additionally, I experimented with connecting the VBUS with resistor devider (33k and 82k) to the PA9 and then I tried to connecting VBUS directly to PA9.

Furthermore, I installing the STM32 Virtual COM Port Driver on win7 32bit and win10 (win8 64bit). Both have the same result: 

prtscr1.jpg

Same result: DeviceFailedEnumeration : Unknown Device.

Do you have any idea why this enumeration issue is occurring?

 

Thank you very much.

 

Sincerely

Radek

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1 reply

Pavel A.
Mar 13, 2025 1:31 AM UTC

Hardware USB analyzer is your friend. It will show what the host sends and how the STM32 responds. Trace messages in the STM32 device firmware can be helpful too.