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Problem opening Virtual COM Port on Windows 7/PuTTY

I have a DK-LM3S9B96 dev kit attached to a Win7 box.  I want to try some of the TI-RTOS examples which use the virtual com port created when I plug in the dev board. 

My problem is that PuTTY does not open the virtual com port (COM4) so I cannot get any System_printf() messages on the PC. 

I have downloaded the latest version of PuTTY and verified the windows_driver is the latest version. 

Is there something else I should be doing?

  • Hi,

    Which version of TI-RTOS are you using? Which example are you trying to run?

    I'm assuming the emulation is working properly since you can load the device. Just to make sure, you realize the UART goes through the same USB. Have you opened Window's Device Manager to verify that COM4 is the correct port? What config parameters are you using in PuTTY (e.g. 115200, etc.).

    Todd

  • Hi Todd,

    I am running TI-RTOS_01_01_00_25.  I successfully ran the gpiointerrupt example. 

    I got the COM4 port number from the DeviceManager.  It does not matter what I put into the PuTTY config, it does not open the port window.  It just beeps when I click OPEN.

    I am running on an ASUS laptop with no comm ports.  Only when I plug in the DK-LM3S9B96 board do I see the virtual com port.

    Bill

  • The output for the gpioInterrupt example does not go out the UART. Please read the output in the CCS console window. The first System output goes to the console and the rest can be viewed in ROV->SysMin. The UART Console example uses the UART to output the System_printf output (and printf also).

    Todd

  • Thank you for the info about using the UART console example instead of the GPIO interrupt example to see the serial output.  However, that only answers half of my question.  I cannot get PuTTY to open the virtual COM port.  I know this does not sound like a TI problem, but the virtual COM port is created when I plug in the USB connection to the DK-LM3S9B96 kit.  When I unplug the USB connection, the virtual COM port disappears.  Has anyone seen this behavior before and, if so, how can it be fixed?

    Bill

  • Can you try uartEcho? What baudrate are you using. Below are both Device Manager and PuTTY settings that worked for me.

    Todd

  • This question is an year old. But I am answering for those who face beginner issues. 

    COM port is visible only when the device is connected. When you unplug the USB connection, it is natural for the COM port to disappear.

    Coming to the Putty problem, you are right about it not being a TI issue. Nor is it an issue with PuTTY or windows. Have you selected the serial radio button from session menu before  trying to open the COM port? I forget it sometimes and hear the bell sound and PuTTY does nothing. Your problem sounds exactly the same. 



  • hey sudhir ^^^

    just wanted to thank you for updating this. I had this exact problem, and you solved it perfect. Thanx again

    -Sincerely

    Random person behind a google search

  • Thanks Sudir. Helped me out much.
  • Now it's at least 3 years later, and this was exactly the hint I needed for something else. (I haven't used serial ports in ages). THANK YOU SO MUCH for saving me a ton of time with putty just beeping at me.

    Robin =)