• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 30 subscribers
  • Views 1025 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ftdi driver receiver stops

Richard Bland
Expert 2050 points

Hi E2E,

I have a LM4F120 launchpad. I am making extensive use of the virtual com port and I find it's receiver (data sending from LM4F to PC) will just stop for some reason. If I connect up an rs232 interface and use a real com port, the exact same code runs fine. It doesn't much matter as my target design will use a real com port, but I wondered if anyone else had this problem. Also how do I check if I haver the latest FTDI driver and where would I get it from?

Thanks, Richard

  • 0
    Guru 117855 points

    Richard Bland said:
    how do I check if I haver the latest FTDI driver and where would I get it from?

    Surprisingly - the FTDI site appears a good first start...

  • 0 in reply to cb1_mobile
    Expert 2050 points

    Well yes, thanks, I've been there of course, but the version numbers don't make sense. Perhaps I should have said where do I find the latest "stellaris virtual serial port" drivers? The one on my pc says v2.0.9270.0 dated 3/8/2012, which sounds old to me. I have great difficulty with the TI site just not responding so searching is almost impossible for some annoying reason.

    Thanks, Richard

  • 0 in reply to Richard Bland
    TI__Guru**** 244400 points

    Richard,

    I may have seen this issue earlier. Is this a Windows7 PC? There is an option in the device manager (in case it is a Windows7 PC), where the USB port gets powered/disabled if let idle. The option is selected by default as a Power Saving Option. Unselecting this may help if my hunch is correct.

    Amit

  • 0 in reply to Amit Ashara
    Expert 2050 points

    Thanks Amit, this is a Windows7 PC. I can't find the setting you refer to but there's no evidence of the power going off ie the launchpad stays running, but it's a good idea, I'll keep looking around the power options. Eventually I found by uninstalling and ticking the delete files box I could change the version of the "Stellaris virtual Serial port" driver, but all the versions I have (from the various Stellarisware and Tivaware that I have) behave the same. I did also find the place to download them from on the TI site too, although these appear to be older still!

    Richard

  • 0 in reply to Richard Bland
    TI__Guru**** 244400 points

    Hi Richard

    The option would be in Device Manager -> Universal Serial Bus controllers -> USB Root Hub -> Power Management

    So far I have not seem a problem with FTDI drivers on WinXP, but on Win7 this did happen. I agree the Power to the board used to be turned off in my case, which got restored if at any time I moved the mice/keyboard, but Serial Port did not recover. It is worth the effort to eliminate this before checking for the FTDI driver versions.

    Amit

  • 0 in reply to Amit Ashara
    Expert 2050 points

    Thanks Amit - found these and unticked them so they cannot get switched off. Will see if this improves reliability.

    During development, usually due to programming errors, one has to reset, repower, go to beginning of main in debugger etc. many times. As you say, sometimes the virtual serial port does not stand up to this treatment and stops working. It can be very frustrating hunting for a software problem which turns out to be the serial port driver. I now usually leave my scope monitoring the rx and tx lines to be sure.

    I was hoping someone would point me at a more robust driver that didn't suffer from this!

    Thanks anyway - Richard