Display changes of integer variable to lcd number

[micmec]

Thanks for the reply stampede.
I will learn about QUdpSocket. One more question. Do I have to use timer to make it always be updated until I close it? I have already learned some about timer.

[stampede]

Do I have to use timer to make it always be updated until I close it?

I don't know how this robot works, but if it's constantly broadcasting packets, then it's enough to connect to a "readyRead()" signal of the QUdpSocket object. Your slot will be called each time a new data arrives on the socket. So it should be enough to do the ui update in this slot.

[micmec]

Thanks a lot for giving so much help.
I have tried some examples with QUdpSocket, but the data was updated too fast. Is there a way to slow it down? And the example I tried is sending and receiving data with a type like String or char. Is there a way to send and receive integer or float value?

This is the example code.

main.cpp

#include "udp.h"
#include <QApplication>
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
 
    UDP w;
    UDP Server;
    UDP client;
    QByteArray ba("Hello world");
    char *data = ba.data();
    while (*data) {
        client.SayHello(*data);
        ++data;
    }
    w.show();
 
    return a.exec();
}

#include "udp.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    UDP w;
    UDP Server;
    UDP client;
    QByteArray ba("Hello world");
    char *data = ba.data();
    while (*data) {
        client.SayHello(*data);
        ++data;
    }
    w.show();
    
    return a.exec();
}

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udp.cpp

#include "myudp.h"
 
MyUDP::MyUDP(QObject *parent) :
    QObject(parent)
{
    socket = new QUdpSocket(this);
    socket->bind(QHostAddress::LocalHost,1234);
    connect(socket,SIGNAL(readyRead()),this,SLOT(ReadyRead()));
 
}
 
void MyUDP::SayHello()
{
    QByteArray Data;
    Data.append("Hello from UDP Land");
    socket->writeDatagram(Data,QHostAddress::LocalHost,1234);
}
 
void MyUDP::ReadyRead()
{
    QByteArray Buffer;
    Buffer.resize(socket->pendingDatagramSize());
 
    QHostAddress sender;
    quint16 senderPort;
    socket->readDatagram(Buffer.data(),Buffer.size(),&sender,&senderPort);
 
    qDebug() << "Message from: " << sender.toString();
    qDebug() << "Message port: " << senderPort;
    qDebug() << "Message: " << Buffer;
}

#include "myudp.h"

MyUDP::MyUDP(QObject *parent) :
    QObject(parent)
{
    socket = new QUdpSocket(this);
    socket->bind(QHostAddress::LocalHost,1234);
    connect(socket,SIGNAL(readyRead()),this,SLOT(ReadyRead()));

}

void MyUDP::SayHello()
{
    QByteArray Data;
    Data.append("Hello from UDP Land");
    socket->writeDatagram(Data,QHostAddress::LocalHost,1234);
}

void MyUDP::ReadyRead()
{
    QByteArray Buffer;
    Buffer.resize(socket->pendingDatagramSize());

    QHostAddress sender;
    quint16 senderPort;
    socket->readDatagram(Buffer.data(),Buffer.size(),&sender,&senderPort);

    qDebug() << "Message from: " << sender.toString();
    qDebug() << "Message port: " << senderPort;
    qDebug() << "Message: " << Buffer;
}

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[Lesiok]

Update is very fast because You are receiving all data after start QApplication (line 19). Remember that the signals and slots only works when event loop is working which is run by the QApplication::exec(). Thus, all the QUdpSocket::readyRead signals be handled only after line 19.