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morgan23
Visitor II
February 27, 2011
Question

STM32 USB Virtual COM port driver Win7

  • February 27, 2011
  • 8 replies
  • 2887 views
Posted on February 27, 2011 at 10:15

STM32 USB Virtual COM port driver Win7

    This topic has been closed for replies.

    8 replies

    Nickname12657_O
    Associate III
    May 17, 2011
    ColdWeather
    Senior
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    USB Communication Device Class (CDC), or Virtual COM Port, is a standart USB device class supported by any modern Windows without any additional user driver.

    Plug and Play: as soon as the CDC/Virtual COMport demo is started and the ST board is connected via USB cable to the PC running Win7, the system recognizes the new device and shows it in the Device Manager.

    Nickname12657_O
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    Hi ,

    Could You please let me know and if possible to attach me the failing Screenshots.  It is quite strange that W7 is not working fine as we have already Certified it at Microsoft WHQL : either x86 and x64 versions.

    Cheers,

    STOne-32.

    greg_t
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    It will not work with Windows 7

    Clifford1
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    I have experienced problems with Windows 7 x64 using the x64 version of the driver.  Device Manager shows the device, but no connection can be made.

    [edit]Further testing on Windows 7 32bit reveals the same problem. See Device Manager screen-shot below.  The target remains permanently stuck in the USB interrupt context.  The target in this case is an STM32F105VC (connectivity line)

    0690X00000604vfQAA.png

    greg_t
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    when connecting my board to PC with winXP the usb is recognized but when connected to win7 the usb is not recognized

    Clifford1
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    I appear to have fixed this issue, it was a problem with the target device implementation not the driver.

    My implementation modifies the rather basic example VCP code to make it more general, to have the same API as my USAT driver, and to integrate it with Keil RTX RTOS kernel.  Getting that right was key to the port being correctly recognised it seems; though it was working on XP.

    It is a shame that the example code is so specialised and poorly documented that adapting it for one's own needs risks breaking it.
    Clifford1
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 14:26

    I appear to have fixed this issue, it was a problem with the target device implementation not the driver.

    My implementation modifies the rather basic example VCP code to make it more general, to have the same API as my USAT driver, and to integrate it with Keil RTX RTOS kernel.  Getting that right was key to the port being correctly recognised it seems; though it was working on XP.

    It is a shame that the example code is so specialised and poorly documented that adapting it for one's own needs risks breaking it.