I am using QCanBus for reading CAN data. I am tring to convert QString to QByteArray and hence convert them to decimal values.? The code is not efficient ?any suggestions?

[rmk1842]

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QCanBus>
#include <QCanBusFrame>
#include <QtDebug>
#include<iostream>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    if (QCanBus::instance()->plugins().contains(QStringLiteral("socketcan")))
    {
        qWarning() << "plugin available";
    }

    QString errorString;
    QCanBusDevice *device = QCanBus::instance()->createDevice(
        QStringLiteral("socketcan"), QStringLiteral("can0"), &errorString);
    if (!device)
    {
        qWarning() << errorString;
    } else
    {
        device->connectDevice();
        std::cout << "connected can0" << std::endl;

        device->connect(device, &QCanBusDevice::framesReceived, [device]()
        {
        QCanBusFrame frame = device->readFrame();
        QString testV = frame.toString();
        QString text = testV.toUtf8().constData();
        QByteArray tempArray = text.toLatin1();
        QList<QByteArray>qbList = tempArray.split(' ');
        QByteArray dataBytes;
        dataBytes.reserve(qbList.count());
        int dbIndex = qbList.count() - 1;
        bool ok;
        for (int i = 0; i < qbList.count(); i++, dbIndex --) {
          unsigned char c;
          c = qbList.at(i).toUInt(&ok, 16) & 0xff; // guard against sign extension
          dataBytes[dbIndex] = c;
        }
        // check the values in dataBytes
        for (int i = 0; i < dataBytes.count(); i++)
        {
          printf("0x%02x\n", dataBytes[i] & 0xff);

        }


        });
    }
}

MainWindow::~MainWindow()
{
    delete ui;
}

Edit aha_1980: added code tags

[aha_1980]

Hi @rmk1842,

If I get it correctly, your code:

device->connect(device, &QCanBusDevice::framesReceived, device
{
QCanBusFrame frame = device->readFrame();
QString testV = frame.toString();
QString text = testV.toUtf8().constData();
QByteArray tempArray = text.toLatin1();
QList<QByteArray>qbList = tempArray.split(' ');
QByteArray dataBytes;
...

can be simplified to.

device->connect(device, &QCanBusDevice::framesReceived, [device]() {
   const QCanBusFrame frame = device->readFrame();
   QByteArray dataBytes = frame.payload();
   std::reverse(dataBytes.begin(), dataBytes.end());

   // check the values in dataBytes
   for (int i = 0; i < dataBytes.count(); i++)
   {
      printf("0x%02x\n", dataBytes.at(i) & 0xff);
   }
});

Edit: I just saw you want the databytes in reverse order. Fixed my example

Regards

[rmk1842]

how to print in the qdebug and view them? printf is taking too much buffer time to view them and also i want to convert them to decimal values.