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Recycling Com port numbers while testing MicroZed boards

Former Member

Hi,

I have an application using a MicroZed board and a custom carrier board. Now that it is almost ready I would like to test multiple combinations of these two.
Some of the initial testing is done buy means of the USB <=> serial port bridge chip.

That works just fine but every time I connect a different MicroZed board a different driver is installed and an individual com port number is assigned.

How could I arrange things so that it always uses the same com port number when I connect to a MicroZed board.

It would make life a bit easier so any suggestion/idea would be much appreciated.

  • 0

    The CP2104 USB-UART used on the MicroZed has a unique serial number for each device. This is normally a good feature in that you can connect multiple MicroZed SOMs to a host at the same time and each will automatically be assigned an individual driver/com port.

     

    In the case of testing though it can be annoying. We ran into this issue with testing at our CM (Contract Manufacturer) and determined that there were 3 options:

     

    1.       CM has to uninstall the COM after each test

    2.       CM has to specifically assign the COM during each test

    3.       CM lets the PC increment the COM, and likewise has to increment their Terminal connection. After 50+ tests, they’ll have to go in and delete all the unused COM ports.

     

    There might be one other possibility if you have a limited number of unique MicroZeds that you wanted to exchange repeatedly. This app note from SiLabs indicates that you can reprogram the ID in the CP2104:

     http://www.silabs.com/support%20documents/technicaldocs/an144.pdf

     

    You might be able to program all of your MicroZed CP2104s to the same ID number, as long as you never plan to have more than one attached to the host at the same time. I have not tried this.

     

    -Gary