How to read ? QSerialPort

lordumuzca

Arduino send me "degreevalue,distancevalue." .constantly sending different values. I have to write two different places.as the submitted values change, the displayed value must change as well.
for example:
place1 = degreevalue
place2 = distancevalue
how can i write

lordumuzca

Actually i want code like this. i tried different types but i couldn't write

void serialEvent (Serial myPort) { // starts reading data from the Serial Port
  // reads the data from the Serial Port up to the character '.' and puts it into the String variable "data".
  data = myPort.readStringUntil('.');
  data = data.substring(0,data.length()-1);
  
  index1 = data.indexOf(","); // find the character ',' and puts it into the variable "index1"
  angle= data.substring(0, index1); // read the data from position "0" to position of the variable index1 or thats the value of the angle the Arduino Board sent into the Serial Port
  distance= data.substring(index1+1, data.length()); // read the data from position "index1" to the end of the data pr thats the value of the distance
  
  // converts the String variables into Integer
  iAngle = int(angle);
  iDistance = int(distance);
}

mostefa

Hi @lordumuzca

Maybe you can get inspired from Qt Serial Port Examples

SGaist

Hi,

To add to @mostefa, type casting a string to an it like that is wrong. QString provides dedicated methods for conversion from string to int and other numeric types.

lordumuzca

#include "dialog.h"
#include "ui_dialog.h"
#include <QSerialPort>
#include <QSerialPortInfo>
#include <QDebug>
#include <QtWidgets>
#include <QString>
#include <string>


Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    ui->degree_lcdNumber->display("---");
    ui->distance_lcdNumber->display("---");
    arduino_is_available = false;
    arduino_port_name = "";
    arduino =new QSerialPort;
    serialBuffer = "";

    foreach (const QSerialPortInfo &serialPortInfo, QSerialPortInfo::availablePorts()) {
        if(serialPortInfo.hasVendorIdentifier() &&serialPortInfo.hasProductIdentifier()){
            if(serialPortInfo.vendorIdentifier() == arduino_uno_vendor_id){
                if(serialPortInfo.productIdentifier()== arduino_uno_product_id){
                    arduino_port_name = serialPortInfo.portName();
                    arduino_is_available = true;

                }
            }
        }

    }
    if(arduino_is_available){
        //open and configure the port
        arduino->setPortName(arduino_port_name);
        arduino->open(QSerialPort::ReadWrite);
        arduino->setBaudRate(QSerialPort::Baud9600);
        arduino->setDataBits(QSerialPort::Data8);
        arduino->setParity(QSerialPort::NoParity);
        arduino->setStopBits(QSerialPort::OneStop);
        arduino->setFlowControl(QSerialPort::NoFlowControl);
        QObject::connect(arduino,SIGNAL(readyRead()),this,SLOT(serialReceived()));

    }else{
        //give error message
        QMessageBox::warning(this,"Port Error","Couldn't find the Arduino!");
    }
}


Dialog::~Dialog()
{
    if(arduino->isOpen()){
        arduino->close();
    }
    delete ui;
}

void Dialog::serialReceived(){

     QStringList bufferSplit = serialBuffer.split(".");

        serialData = arduino->readAll();
        serialBuffer += QString::fromStdString(serialData.toStdString());

//      serialBuffer  = ",";
                      qDebug()<<bufferSplit;
}
void Dialog::updateLCD(const QString sensor_reading){
//    ui->degree_lcdNumber->display(sensor_reading);
}

my output
alt text

i want to display before comma in LCD1, after comman is in LCD2. i tried different things but i cant.
maybe each double is new line like this.maybet better
"xx,xx"
"xx,xx"

SGaist

You can use a regexp to retrieve both numbers from your string.

Also note that your conversion to std string are useless, QString already provides handling fro QByteArray.