Missing Data Read From Qt

[MG33]

Hi, ı am ne in Qt. I was trying to send data from STM32f407vg to Qt. The data is produced by RTC module and gives time, date (for example, 2024-03-11T17:01:24+08:00Monday). However the data read by Qt is not full in text edit always. It is like a loop below and repeated always.

2
2
2
20
20
20
202
202
202
2024
2024
2024
2024-
2024-
2024-
2024-0
2024-0
2024-0
2024-03
2024-03
2024-03
2024-03-
2024-03-
2024-03-
2024-03-1
2024-03-1
2024-03-1
2024-03-11
2024-03-11
2024-03-11
2024-03-11T
2024-03-11T
2024-03-11T
2024-03-11T1
2024-03-11T1
2024-03-11T1
2024-03-11T17
2024-03-11T17
2024-03-11T17
2024-03-11T17:
2024-03-11T17:
2024-03-11T17:
2024-03-11T17:0
2024-03-11T17:0
2024-03-11T17:0
2024-03-11T17:01
2024-03-11T17:01
2024-03-11T17:01
2024-03-11T17:01:
2024-03-11T17:01:
2024-03-11T17:01:
2024-03-11T17:01:1
2024-03-11T17:01:1
2024-03-11T17:01:1
2024-03-11T17:01:17
2024-03-11T17:01:17
2024-03-11T17:01:17
2024-03-11T17:01:17+
2024-03-11T17:01:17+
2024-03-11T17:01:17+
2024-03-11T17:01:17+0
2024-03-11T17:01:17+0
2024-03-11T17:01:17+0
2024-03-11T17:01:17+08
2024-03-11T17:01:17+08
2024-03-11T17:01:17+08
2024-03-11T17:01:17+08:
2024-03-11T17:01:17+08:
2024-03-11T17:01:17+08:
2024-03-11T17:01:17+08:0
2024-03-11T17:01:17+08:0
2024-03-11T17:01:17+08:0
2024-03-11T17:01:17+08:00
2024-03-11T17:01:17+08:00
2024-03-11T17:01:17+08:00
2024-03-11T17:01:17+08:00M
2024-03-11T17:01:17+08:00M
2024-03-11T17:01:17+08:00M
2024-03-11T17:01:17+08:00Mo
2024-03-11T17:01:17+08:00Mo
2024-03-11T17:01:17+08:00Mo
2024-03-11T17:01:17+08:00Mon
2024-03-11T17:01:17+08:00Mon
2024-03-11T17:01:17+08:00Mon
2024-03-11T17:01:17+08:00Mond
2024-03-11T17:01:17+08:00Mond
2024-03-11T17:01:17+08:00Mond
2024-03-11T17:01:17+08:00Monda
2024-03-11T17:01:17+08:00Monda
2024-03-11T17:01:17+08:00Monda
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
(the loop always repeated)

When ı tested in termit terminal, the data is read properly like

2024-03-11T17:01:17+08:00Monday

The data is transmitted in stm32

sprintf(buffer, "%04d-%02d-%02dT%02d:%02d:%02d%+03d:%02d%s\n",
	  	  	  year, month, date, hour, minute, second, zone_hr, zone_min, DAYS_OF_WEEK[dow]);

HAL_UART_Transmit(&huart3, buffer, strlen(buffer), 1000);

The data is read by qt code

void Widget::Read_Data()
{

     //to make debug:
    serialData = serialPort.readAll();
    serialBuffer += QString::fromStdString(serialData.toStdString());
    qDebug() << serialBuffer;


    QStringList bufferSplit = serialBuffer.split("\n"); 
    if(bufferSplit.length() < 3)
    {
        serialData = serialPort.readAll();
        serialBuffer += QString::fromStdString(serialData.toStdString());
    }

    else //bufferSplit[0] is a good value
    {
        qDebug() << bufferSplit;
        serialBuffer = "";
    }

    ui->display_line->append(bufferSplit[0]);

}

The data is splitted (according to \n) and stored in the buffer to be read.

The bufferlist is below and ı have taken 0. index

QList("2024-03-11T17:01:24+08:00Monday", "2024-03-11T17:01:25+08:00Monday", "")

[jsulm]

@MG33 said in Missing Data Read From Qt:

QStringList bufferSplit = serialBuffer.split("\n");
if(bufferSplit.length() < 3)
{
serialData = serialPort.readAll();
serialBuffer += QString::fromStdString(serialData.toStdString());
}

What's the point to call readAll() again here? You already read all available data above.
You will get more data next time Read_Data is called. And you only should set the data in UI if you got complete data, currently you always set it, doesn't matter whether you got everything or not.

[JonB]

@MG33
As @jsulm has said. But additionally when do you call Read_Data()? Is that a slot on the readyRead() signal or called from somewhere else?

[MG33]

@jsulm i do not repat, the characters on the data is sorted one under the other. How can ı solve that ?

[JonB]

@MG33
Don't understand what you are asking now.
Let me know when you fancy answering when and how often you call Read_Data(). Your output indicates it is being called repeatedly 3 times per each byte individually received.
And no indication of any missing data.

[MG33]

@JonB ı have connect button and the signal is there

connect(&serialPort,SIGNAL(readyRead()),this,SLOT(Read_Data()));

[JonB]

@MG33
The output you display shows groups of 3 lines at a time, after each of which another single character is appended, building towards the whole string having been received. You could check how many bytes are being received by each realAll() call.

Is there any chance you have executed that connect() statement 3 times?

At this point you should make the rest of the code as minimal as possible and show it.

There shouldn't be any need of a QTextEdit or anything else in a UI to test/debug your issue, whatever it is.

[MG33]

@JonB my point is read the data like

2024-03-11T17:01:24+08:00Monday
2024-03-11T17:01:25+08:00Monday
2024-03-11T17:01:26+08:00Monday
2024-03-11T17:01:27+08:00Monday

however the data flows like that

2
2
2
20
20
20
202
202
202
2024
2024
2024
2024-
2024-
2024-
2024-0
2024-0
2024-0
2024-03
2024-03
2024-03
2024-03-
2024-03-
2024-03-
2024-03-1
2024-03-1
2024-03-1
2024-03-11
2024-03-11
2024-03-11
2024-03-11T
2024-03-11T
2024-03-11T
2024-03-11T1
2024-03-11T1
2024-03-11T1
2024-03-11T17
2024-03-11T17
2024-03-11T17
2024-03-11T17:
2024-03-11T17:
2024-03-11T17:
2024-03-11T17:0
2024-03-11T17:0
2024-03-11T17:0
2024-03-11T17:01
2024-03-11T17:01
2024-03-11T17:01
2024-03-11T17:01:
2024-03-11T17:01:
2024-03-11T17:01:
2024-03-11T17:01:1
2024-03-11T17:01:1
2024-03-11T17:01:1
2024-03-11T17:01:17
2024-03-11T17:01:17
2024-03-11T17:01:17
2024-03-11T17:01:17+
2024-03-11T17:01:17+
2024-03-11T17:01:17+
2024-03-11T17:01:17+0
2024-03-11T17:01:17+0
2024-03-11T17:01:17+0
2024-03-11T17:01:17+08
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2024-03-11T17:01:17+08:
2024-03-11T17:01:17+08:
2024-03-11T17:01:17+08:
2024-03-11T17:01:17+08:0
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2024-03-11T17:01:17+08:00
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2024-03-11T17:01:17+08:00
2024-03-11T17:01:17+08:00M
2024-03-11T17:01:17+08:00M
2024-03-11T17:01:17+08:00M
2024-03-11T17:01:17+08:00Mo
2024-03-11T17:01:17+08:00Mo
2024-03-11T17:01:17+08:00Mo
2024-03-11T17:01:17+08:00Mon
2024-03-11T17:01:17+08:00Mon
2024-03-11T17:01:17+08:00Mon
2024-03-11T17:01:17+08:00Mond
2024-03-11T17:01:17+08:00Mond
2024-03-11T17:01:17+08:00Mond
2024-03-11T17:01:17+08:00Monda
2024-03-11T17:01:17+08:00Monda
2024-03-11T17:01:17+08:00Monda
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
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2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
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2024-03-11T17:01:17+08:00Monday
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2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday
2024-03-11T17:01:17+08:00Monday

how can ı solve that ?

[JonB]

@MG33 You have repeated the same information as in your first post. I suggest you re-read my last reply and act to find your issue.

[jsulm]

@MG33 I already told you what you're doing wrong. Just read it and act accordingly instead of repeating same information again and again.
Accumulate data in a buffer until you got a complete package and then parse it and update your UI.