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  1. #1
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    Default quint16 to QByteArray Conversion

    Hello All,

    I begin to work with Qt so sorry if the answer is easy for you.
    I am working on a software which communicates with a device.
    I use the QextSerialPort librairie and it is working fine.

    In fact, it is working fine when I send to my device a constant frame.
    Qt Code:
    1. /* Erasing Command */
    2. static const char eraseCmd[] = {0x11, 0x02, 0x00, 0x00, 0x00, 0x02 };
    3. QByteArray Command = QByteArray::fromRawData(eraseCmd, sizeof(eraseCmd));
    To copy to clipboard, switch view to plain text mode 

    But it is not working when I want to add in the frame a counter as an idFrame;
    For example, if I send the 499th frame, I would like to send :
    {beginning if the frame....,0x01, 0xF3,...end of the frame }.

    I try a lot of functions, but maybe not the good one, like setNum(idFrame,16) but it returns :
    Frame[X] = 3 ;
    Frame[X+1] = F ;
    Frame[X+2] = 1 ;

    The best way for me will be to get :
    Frame[X] = "0x01" ;
    Frame[X+1] = "0xF3" ;

    Can someone help me ?
    Thank you in advance for your support.

    Zidoune

  2. #2
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    Default Re: quint16 to QByteArray Conversion

    Something like this (frame_no is 2 byte unsigned integer) :
    Qt Code:
    1. Frame[X+2] = frame_no % 0xFF ;//lower byte
    2. Frame[X+1] = frame_no / 0xFF ;//higher byte
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  3. #3
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    Default Re: quint16 to QByteArray Conversion

    Thank you for your help Lesiok !

  4. #4
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    Default Re: quint16 to QByteArray Conversion

    You need to understand the difference between the one byte number 0xF3 (243 in decimal) and the 5 byte string "0xF3" or to understand why setNum() was not the correct approach.

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