Easylogger not enumerated on one computer

General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
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iphi
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Easylogger not enumerated on one computer

Post by iphi » Tue Jan 06, 2009 11:31 pm

Hi,

I have a problem with Easylogger on one specific computer:

While the device works fine on most computers, it is not recognized/not enumerated on any of 8 USB outlets on one specific computer (WinXP like all other tested ones). All outlets work fine with other USB devices like a mouse.

Strange thing:
When I leave the device connected and I reboot the machine, then it is recognized. But unplugging and replugging it then will cause detect failure again.

Does anybody have a clue for the reason and for remedy?

Thanks,
Tom

iphi
Rank 2
Rank 2
Posts: 68
Joined: Mon Jun 25, 2007 11:37 am

Post by iphi » Sun Jan 11, 2009 11:25 am

I'm still desperately searching for the reason why this happens.
Can't anybody give a hint on a search strategy for the cause of the enumeration failure?

What can be learned from the fact that enumeration works if the system is rebooted with the device plugged in, but not when un- and replugged?

Thanks, Tom

christian
Objective Development
Objective Development
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Joined: Thu Nov 09, 2006 11:46 am

Post by christian » Wed Jan 21, 2009 7:45 pm

This is most likely a voltage level problem. Please check the voltage level on D- in idle mode.

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