USB device detection in win mobile 6.5 RRS feed

  • Question

  • Hello,

    We have an issue in which the USB connection is not properly made between a printer and an handheld computer (using win mobile 6.5). The printer use USB to emulate serial printing. We usually find the right COM port to use in the registry but, in some cases, the port cannot be found (and connection cannot be established with any of them). Theses cases I refer to are either when the device reboot while in the printer or when it goes to sleep (and came back while in the printer).

    I wrote to the printer manufacturer (datamax; which also made the USB CDC driver) but did not get an answer. Do you think this is a driver issue or is it more related to the OS? Is there any way to fix this?


    Wednesday, October 29, 2014 1:16 PM

All replies

  • Hi adumoulin,

    From your description, you can't find the right COM port to use either when the device reboot while in the printer or when it goes to sleep. Maybe it is related with the driver of printer due to this issue will happen when then printer reboot or goes to sleep. Maybe it doesn't support the re-connect in the above condition. You can re-read the usb when the situation happens.

    Or you take the suggestion there: , using Bluetooth. 

    "looking into more realistic scenarios such as using Bluetooth with BT to serial port adapter connected to uC."

    Best regards,

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    Thursday, October 30, 2014 10:04 AM
  • More precisely, we read the registry at 'Drivers\\USB\\ClientDrivers\\USBCDC_Template_Default' to find to right COM port. In this situation, the registry entry does not even exists.

    Also, we don't read the USB, we only use a 'CreateFile' on the COM port. Could you point me in the right direction about 'reading the usb'?


    Thursday, October 30, 2014 8:38 PM