Discussion in 'Probleme / Fehler' started by Oceanflyer, Jun 21, 2014.

  1. Oceanflyer

    Oceanflyer New Member

    Problem with Silicon Labs CP210x USB to UART Bridge in Windows XP and the Solution:

    In case you connect a second Charger, Windows XP tries to install it and says that there has been a problem and that the device will not work correctly. In Device Manager, you see the problematic device with a yellow question mark in the "Ports (COM & LPT)" category (that replaced the first one and appears as Silicon Labs CP210x USB to UART Bridge (COMxx)") and when you double click on it, it says : Windows can not load the device driver for this hardware because there is a duplicate device already running in the system (code 42)". Then none of the two are working anymore.

    Reason & Solution:
    A Windows PC cannot install more than one CP210x device if they have the same VID (Vendor ID), PID (Product ID), and Serial Number. The VID/PID/Serial number combination act as an address for the device. In order to use multiple CP210x devices on the same PC, you will need to change the serial number in the device from the default value using the CP21xxCustomizationUtility in AN721: Download here: http://www.silabs.com/Support Documents/Software/an721sw.zip
    This utility may not be compatible with all versions of the driver, so you may need to upgrade your driver to the latest version: http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx
    After downloading the software, open the utility and connect one CP210x device to the PC. Then, hit the Refresh button in the utility, and the device should appear. Change the serial number to another value other than 0001, and hit the Program Device button. You should then be able to connect multiple CP210x devices to the PC.
    There might come a Failure-message:"java.lang.UnsatisfiedLinkError: Unable to load library 'slab_usb_spi': The specified module could not be found." Here the problem is that the SLAB_USB_SPI.dll requires WinUSB, which is not native to Windows XP.
    Please download "winusb.dll" from the Net (e.g. http://downloads.tether.com/winusb.dll ) and save in your Folder "\WINDOWS\system32". then the CP21xxCustomizationUtility should work as planned.

    We figured this our yesterday and found it worth to summarize here.

    Brgds, Andreas

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