QSerialport with arduino problem

[lotin]

Hi,
i have a problem with comunication between pc and arduino uno.
I have this code for communicating:
<code>

serial->write(data_char);    
int waitTimeout = 1000;
if (serial->waitForBytesWritten(waitTimeout)) {      
    if (serial->waitForReadyRead(waitTimeout)){
        QByteArray response =  serial->readAll();
        qDebug() << "response" << response;
    } else {
        qDebug() <<"Wait read response timeout %1";
    }
} else {
    qDebug() << "Wait write request timeout %1";
}

</code>
I want to send data and wait until arduino answers.
Ok, it send data and waiting for response, but i getting the actual response and the previous response to.

For example:
I will connect the program with serial port and send first "message" , for example 12, and the first response is ok, i get 12.
But when now i send, for example 78, the response is "1278".
And then when i send for example 3, the response is "783".
.
.
.

I´ve tried lots of possibilities, but nothing were good. Can you help me please. Thank you.

Program in arduino works fine in terminal.

[kuzulis]

You can try to check it with the Terminal example which comes with the QSerialPort

[lotin]

Yes, i made this program by the terminal example.

I solve it. I use QStringList to delete the first response.

But, i thank you for for answer.