How to modify timing in readyRead of QextSeriaport



  • Dear All,

    I've a problem with the QExtSerialPort in QT. I'm developing for an IMX6UL CPU under a linux based operating system.

    I've noticed that, at baud 9600, SIGNAL readyRead is "active" about 35ms after having sent my serial string (which is composed of 3 characters, so about 3ms)

    In this way, if I try to communicate with the CPU, I can use a maximum frequency of about 30Hz, which is too low for my application.

    Furthermore, if I use lower baudrates, the time of 35 ms becomes bigger ( 80ms for 4800, 175 ms for 2400).

    My goal is that readyReady becomes active when I'm not transmitting for a time of 3,5 characters (i.e. or baud of 9600, a time of 3,5 / 4 ms).

    Should I modify the readyread funcion?

    I'd like to keep this library because I've already wrote a lot of code.

    Thank you in advance


  • Moderators

    @mattiad Is there a reason why you don't use http://doc.qt.io/qt-5/qserialport.html ?



  • Dear @jsulm , if I use QSerialport will I be able to reduce this time?


  • Moderators

    @mattiad I don't know. But you could try and see whether it makes any difference.



  • I'll try. I haven't use it because its libraries were not included in the kernel


  • Moderators

    @mattiad What kernel do you mean?



  • Sorry, I meant in the file system . Now I'll try adding the Libqt5serialport.so.5.



  • @mattiad Because this thread is in the category Mobile and Embedded I'll mention, that QSerialPort is not a 100%
    supported for Android and IOS, info: here and here

    For the partial android support take a look here.



  • Dear @J-Hilk thank you for the information. I'm using yocto so I suppose it's fully compatible



  • @jsulm I've tried but I have the same problem. It takes too much time before havin bytes available in the buffer


  • Qt Champions 2016

    @mattiad
    Its not possible to just use higher baud than 9600 ?
    To get better speed i mean.



  • @mrjj yes, I've already tried and verified that it works with higher baud my application must work with a baud of 9600


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