10 months, 2 weeks ago.
Access to USB Port with external program
I am using a LPC1768 as pulse detector (kind of like an oscilloscope). When the unit is attached using a USB cable to a USB 2.0 or USB 3.0 port (COM3) on my Laptop, the port appears to be attached to a program called , WUDFHOST.EXE'. I can not programmatically open the port since it is being used by this driver host and I get the message "COM3 does not exist" using either visual basic, C++, or Labview. I have debugged the LPC1768 program using Hyperterminal so know it is functioning properly and communicating with the terminal emulator. What does Hypererminal do internally to access the port? How do I detach the unit from the driver host so that I can communicate use the virtual USB port on the LPC1768 while the system is running?
10 months, 1 week ago.
We're glad you were able to make some headway and thanks for clarifying the problem. Presumably you are using an Mbed enabled LPC1768 board - such as this one:
If so - your host computer is actually communicating to the LPC1768 through an interface chip that is responsible for handling the board programming and standard i/o. If all is good, your board will show up as a USB mass storage device and if you check your computer's Device Manager you'll see an "mbed Composite Device" under the USB area.
If you're having problems on the laptop you can see if updating the board's firmware will help:
Ralph, Team Mbed
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