Device can't be found after wake up from Windows sleep mode

General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
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Stephen
Posts: 6
Joined: Mon Apr 07, 2008 7:20 am

Device can't be found after wake up from Windows sleep mode

Post by Stephen » Mon Apr 14, 2008 10:26 am

(Solved, problem come from 2005 LibUSB-Win32 driver, after update to 2007 version. No problem. Thanks.)

hi,

I have got two desktop computer for checking my AVR-USB device.

Computer I: USB 5V power would be cut off from the host automatically at Windows sleep mode.

Observation: Application running and control the device -> Application stop (not ended)and device power off (Windows sleep mode) -> device reset (Window wake up, device reset due to from power off to power on) -> Application still running and control the device as 1st stage

Computer II: USB 5V power wouldn't be cut off at Windows sleep mode.

Problem: Application running and control the device -> Application stop (not ended) and device's AVR is still running (Windows sleep mode) -> device hasn't got reset (Window wake up, since device's power is continues and hasn't turn off ) -> Application still running , but can't find the device

My question: (1) Why my device's connection to the host was lost. I can't see any problem for my other usb device such as card reader and hubs. (2) It seems it is not a problem of re-enumeration. It is because my device hasn't got any reset. Thanks.

DavidSimacek
Posts: 1
Joined: Fri Sep 13, 2013 5:57 pm

Re: Device can't be found after wake up from Windows sleep m

Post by DavidSimacek » Sat Oct 12, 2013 1:52 pm

Hi,
I´m struggling with a someting similar. I have AVR-USB device based on VUSB. On the site of PC I´m ussing tool based on usbGenericHidCommunication library. Everyting works fine until I do a restart of computer. The PC tool is among autostart applications, so it starts automatically. Problem is, that sometimes communication between PC tool and AVR-USB device works after restart and somatimes not. Any suggestions?

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