Cant read strings with Raspberry via QtSerial

[bladekel]

Hello to all,
I'am trying to read string coming from arduino to my raspberry. On raspberry pi2, I'm using qt4 with jessie and connecting raspberry with arduino via usb.

I send data from arduino like;

void setup(){
  Serial.begin(9600);
}

void loop(){
Serial.println("123456789");
delay(2000);
}

On the raspberry I'm trying to read like;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    serial = new QSerialPort(this);
    serial->setPortName("ttyACM0");
    serial->setBaudRate(QSerialPort::Baud9600);
    serial->setDataBits(QSerialPort::UnknownDataBits);
    serial->setParity(QSerialPort::NoParity);
    serial->setStopBits(QSerialPort::OneStop);
    serial->setFlowControl(QSerialPort::NoFlowControl);
    serial->open(QIODevice::ReadWrite);
    connect(serial,SIGNAL(readyRead()),this,SLOT(data_received()));

}

void MainWindow::data_received()
{
    QByteArray incomingData;
    incomingData=serial->readAll();
    qDebug(incomingData);
}

With qt terminal example, I read the data perfect.
But with my code above;

12
1
2345
6789


123
4567
89

12
3456
789


1
2345
678
9

123
4567
89

What must I do? Any suggests?

[SGaist]

Hi,

qDebug by default will add a new line at destruction hence what you see.

If you want to modify that behaviour, take a look at this.

[bladekel]

@SGaist
Thanks for your reply.
But when I tried to change the text of a label, or check the received data, I couldnt success.
When I update the text of a label, I got 6789, 23456789, 123456 etc.
And after those tries I saw that with qdebug I couldnt read the data clearly.

And as I sad before , I can read the data clearly with QtSerial terminal example.

What I'm trying to do is, checking the received data and updating the gpio pins...

[SGaist]

The terminal example does only one thing: it appends whatever is received to the Console widget.

The usual way to ensure good communication on a serial port is to have a protocol in place that helps you know when you have received a "full frame" of data.

Then on the receiving part, you accumulate the data in a buffer until you have enough to recreate that frame and then process it.

[bladekel]

@SGaist
Can you suggest me an example ?

[kuzulis]

serial->setDataBits(QSerialPort::UnknownDataBits);

It is best solution! ))

[SGaist]

What kind of example are you looking for ?