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.