bidirectional communication via QTcpSocket

Question

I'm writing an application that communicates via QTcpSocket between Server and Client.

Server is an application with gui on standard pc.

Client is a console application on Raspberry pi.

client.cpp

#include "client.h"
#include <QHostAddress>
#include <cstdio>
Client::Client() :
    QObject()
{
    socket = new QTcpSocket(this);
    printf("try to connect.\n");
    connect(socket, SIGNAL(connected()),
            this, SLOT(onConnected()));
    connect(socket, SIGNAL(readyRead()),
            this, SLOT(readyRead()));
}

void Client::onConnected()
{
    printf("Connection established.\n");
//    char buffer[1024];
//    forever
//    {
//        while(socket->canReadLine())
//        {
//            QByteArray ba = socket->readLine();
//            printf("from server: %s", ba.constData());
//        }
//        printf(">> ");
//        gets(buffer);
//        int len = strlen(buffer);
//        buffer[len] = '\n';
//        buffer[len+1] = '\0';
//        socket->write(buffer);
//        socket->flush();
//    }
}
void Client::readyRead(){
    if(socket->canReadLine())
    {
        QByteArray ba = socket->readLine();
        printf("from server: %s", ba.constData());
    }else{
        printf(":(");
    }
}

void Client::connectToServer()
{
    socket->connectToHost(QString("192.168.0.103"), 5100);
}

server.cpp

#include "server.h"
#include <QTcpServer>
#include <QTcpSocket>
#include <cstdio>
#include <QtDebug>

Server::Server(int listenPort)
    :QObject()
{
    port = listenPort;
    server = new QTcpServer(this);
    connect(server, SIGNAL(newConnection()),
            this, SLOT(onNewConnection()));
}

void Server::listen()
{
    server->listen(QHostAddress::Any, port);
}
void Server::sendMessage(QString message){
    qDebug() << message;
    QByteArray response;
    response.append(message);
  qDebug() <<   socket->peerAddress() ;
    socket->write(response);
    socket->flush();
}

void Server::onNewConnection()
{
    socket = server->nextPendingConnection();

    if(socket->state() == QTcpSocket::ConnectedState)
    {

        qDebug()<<socket->peerAddress();\
        emit onConnectionEstablished(socket->peerAddress().toString());

    }
    connect(socket, SIGNAL(disconnected()),
            this, SLOT(onDisconnected()));
    connect(socket, SIGNAL(readyRead()),
            this, SLOT(onReadyRead()));
}

void Server::onReadyRead()
{

    if(socket->canReadLine())
    {
        QByteArray ba = socket->readLine();

        emit onMessageRecieved(QString(ba));



        QByteArray response("maslO!");

        // some code which parses arrived message
        // and prepares response

        socket->write(response);
        socket->flush();
    }
    //else just wait for more data
}

void Server::onDisconnected()
{
    printf("Connection disconnected.\n");
    disconnect(socket, SIGNAL(disconnected()));
    disconnect(socket, SIGNAL(readyRead()));
    socket->deleteLater();
}

This is the code. So now the problem description:

I'm starting Server application and then Client application on Raspberry. Both apps are connecting I see it in "onNewConnection" method in Server.cpp.

But when I try to send something to Client using "sendMessage" in server.cpp, Client shows nothing. I should recieve data from server in "readyRead" method in client.cpp but it is never called. What did i wrong?

My friend told me to check if i got same version of QT on both platforms. So i checked and it is not but maybe it is the problem?

Raspberry pi, Arch linux without x server

QMake version 3.0
Using Qt version 5.2.1 in /usr/lib

Server, linux mint

QMake version 3.0
Using Qt version 5.2.0 in /home/adam/Qt/5.2.0/gcc_64/lib

Can you also give me some tips to improve this code?