USB detected as Unknown Device

aanantha · ‎2008-06-03

Posted on June 04, 2008 at 00:15

aanantha · ‎2011-05-17

Posted on May 17, 2011 at 12:34

Enabled Pin9 on STM32 eval kit and Host detects the device as Unknown device. Host says USB Device not recognized. Could some one tell what USB initializations i need to do to get my board detected and host can install a drive for the same.

16-32micros · ‎2011-05-17

Posted on May 17, 2011 at 12:34

Hi aanantha,

What is your STM32 Eval kit manufacturer and reference ? Depending on your hardware you should ensure that you have the clocks well configured and pull-up of D+ Pin at high state when plugging USB Cable.

Cheers,

STOne-32.

faris · ‎2011-05-17

Posted on May 17, 2011 at 12:34

Hi,

I have the same problem too. My eval kit is STM32 from Keil.

Which clock configuration should I check to rectify this problem?

Could you please precise the pull-up of D+ pin?

Thank you

janislaw · ‎2011-05-17

Posted on May 17, 2011 at 12:34

Hi, similar problem here.

I checked out the USB developer kit and compiled the CDC (Virtual COM to USART1 connection) project under RIDE7. I had made the necessary changes in source code to fit the board of mine, which is Olimex H103 - just changing the USB enable pin. It worked nice, but just once. After reset I got the ''Unknown device'' error. The same on each other USB socket. The same after numerous resets and driver reinstalls. I am really not fond of reinstalling my Windows XP to check if the drivers would then cooperate with the STM.

Any ideas?

lanchon · ‎2011-05-17

Posted on May 17, 2011 at 12:34

hi janislaw,

are you using usb kit 1 or 2? there's a ''stdio via usb'' post around with code based on usb kit 1 for the olimex header board. maybe you'd like to try it and tell us what happens...

janislaw · ‎2011-05-17

Posted on May 17, 2011 at 12:34

Quote:

are you using usb kit 1 or 2?

The second (recent) version.

Quote:

there's a ''stdio via usb'' post around with code based on usb kit 1 for the olimex header board. maybe you'd like to try it and tell us what happens...

Negative, but the idea was good. I fetched the source. This time it was tailored to my board, so I compiled without changes. It worked, but the same as before, only once. After following resets my Windows gave me ''Unknown Device''

So, then I had two binaries for my board that worked just once. Switching between them didn't help.

What could be the reason for this hysterisis in Windows (I don't suspect the embedded soft)? Maybe there are some registry keys which, once written, block another recognitions of USB devices...

Any ideas this time?

[ This message was edited by: janislaw on 04-06-2008 01:56 ]

lanchon · ‎2011-05-17

Posted on May 17, 2011 at 12:34

I don't have a clue. with the device attached, have you tried to remove the device at the device manager and then scan for new hardware or unplug/replug? does it work again for one time? there's a cache in windows for devices that failed the MOD query (microsoft OS descriptor). I included a *.reg file in the thing you downloaded to remove the cache entry of the stdio vcom. does it make it work again?