Unable to write in serial port using QSerialPort - c++

Question

I am currently trying to make a video games using a controller made of an arduino. I am making the GUI with Qt since I found it really cool that it has an integrated serial port library. So right now i'm trying to set-up the communication of the arduino and the pc with QSerial port, so far I'm able to open the port (not a big deal but it took me hours lol), when I try to write in it it get this error :
<3,2,2,>QObject::startTimer: Timers can only be used with threads started with QThread
Here's the com.h file
#include <QSerialPort>
#include <iostream>
using namespace std;
class Comunication
{
public:
void openSerial();
Comunication();
void closeSerial();
bool sendData(int module, int* tabData, uint8_t tabSize);
private:
QSerialPort* serial;
};
And here's the com.cpp file
#include "com.h"
Comunication::Comunication() {
serial = new QSerialPort;
}
void Comunication::openSerial() {
serial->setPortName("COM5");
serial->setBaudRate(QSerialPort::Baud9600, QSerialPort::AllDirections);
serial->setDataBits(QSerialPort::Data8);
serial->setParity(QSerialPort::NoParity);
serial->setFlowControl(QSerialPort::NoFlowControl);
serial->setReadBufferSize(5000);
serial->open(QIODevice::ReadWrite);
if (serial->isOpen()) {
cout << "opened" << endl;
}
}
void Comunication::closeSerial() {
serial->close();
}
bool Comunication::sendData(int module, int* tabData, uint8_t tabSize)
{
char txData[30];
int index = 0;
txData[index++] = '<';
txData[index++] = module + '0';
for (int i = 0; i < tabSize; i++)
{
txData[index++] = ',';
if (tabData[i] != 'I') {
char tempTab[15];
int sizeTempTab = sprintf(tempTab, "%d", tabData[i]);
for (int j = 0; j < sizeTempTab; j++)
{
txData[index++] = tempTab[j];
}
}
else
txData[index++] = 'I';
}
txData[index++] = ',';
txData[index++] = '>';
txData[index] = '\0';
cout << txData;
if (serial->isOpen()) {
serial->write(txData, index);
}
return 0;
}
I'm sure that the port is open... I dont understand what's wrong, is it because it is running in the main thread ?, If so, how do I correct the situation...
If anyone could help it would be much appreciated.
Have a great day/evening
PS: im using 6.2.3