Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QSerialPort strange behaviour
Qt 6.11 is out! See what's new in the release blog

QSerialPort strange behaviour

Scheduled Pinned Locked Moved Unsolved General and Desktop
3 Posts 2 Posters 328 Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • ocgltdO Offline
    ocgltdO Offline
    ocgltd
    wrote on last edited by
    #1

    My code uses QSerialPort to talk to a serial device (/dev/rfcomm1) - which in fact a bluetooth using SPP protocol.

    Sometimes my program runs fine, but sometimes I can't get the serial device to respond. I try to open/close/open/close to see if I can get my device to respond but it does not.

    However, if I stop my program and restart it then my connection will work. Why would this be? What's the difference between open/close/open and a restart then open? Anything I can do programmatically to simulate a power off to make my device respond?

    J.HilkJ 1 Reply Last reply
    0
    • ocgltdO ocgltd

      My code uses QSerialPort to talk to a serial device (/dev/rfcomm1) - which in fact a bluetooth using SPP protocol.

      Sometimes my program runs fine, but sometimes I can't get the serial device to respond. I try to open/close/open/close to see if I can get my device to respond but it does not.

      However, if I stop my program and restart it then my connection will work. Why would this be? What's the difference between open/close/open and a restart then open? Anything I can do programmatically to simulate a power off to make my device respond?

      J.HilkJ Offline
      J.HilkJ Offline
      J.Hilk
      Moderators
      wrote on last edited by
      #2

      @ocgltd very hard to tell, without seeing your actual code.

      Potential issue I see is that you have two instances of your serialport. The old one is still open, but not connected to your slots anymore and you try to open/close the old one and nothing happens


      Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


      Q: What's that?
      A: It's blue light.
      Q: What does it do?
      A: It turns blue.

      ocgltdO 1 Reply Last reply
      1
      • J.HilkJ J.Hilk

        @ocgltd very hard to tell, without seeing your actual code.

        Potential issue I see is that you have two instances of your serialport. The old one is still open, but not connected to your slots anymore and you try to open/close the old one and nothing happens

        ocgltdO Offline
        ocgltdO Offline
        ocgltd
        wrote on last edited by
        #3

        @J-Hilk I'm sure there is only one instance of QSerialPort. As well, I can successfully open the device (/dev/rfcomm1) so that suggests the port is not in use (or open by another copy) since attempting to open an already open port would fail - i assume.

        Something else must be going on

        1 Reply Last reply
        0

        • Login

        • Login or register to search.
        • First post
          Last post
        0
        • Categories
        • Recent
        • Tags
        • Popular
        • Users
        • Groups
        • Search
        • Get Qt Extensions
        • Unsolved