QSerialPort detecting lost connection - qt

Question

My setup is as follows: Arduino Mega UART3 <--> Voltage Level shifter <--> Rpi4
All the code can be found here
Data is being sent synchronously from the Arduino to the Rpi at 100ms and 1000ms (depending on the importance of the data). And also data is being sent from the Rpi back to the Arduino asynchronously on GUI input (There is also a sync sent at 1000ms in case some frames are lost/corrupted).
Coms are handled in a separate thread than the GUI to provide the best user experience.
Well, all is working fine but I have been trying unsuccessfully to detect if the Rpi has lost connection with the Arduino. (In the other direction is covered with a serial watchdog.)
I wanted to avoid the use of another watchdog in the Qt part but I cannot find a suitable signal to detect the lost serial connection as the QSerialPort keeps reporting a Timeout error randomly... and there are no other methods that detect successfully the disconnection.
Here below is the workaround that I am trying to use without much success: (Probably it needs a major rewrite... but I need to be pointed in the right direction first)
// Serial Port Initialization
m_Serial = new QSerialPort();
m_Serial->setPortName("ttyS0");
//m_Serial->setPortName("ttyUSB0");
m_Serial->setBaudRate(QSerialPort::Baud115200);
m_Serial->setDataBits(QSerialPort::Data8);
m_Serial->setParity(QSerialPort::NoParity);
m_Serial->setStopBits(QSerialPort::OneStop);
m_Serial->setFlowControl(QSerialPort::NoFlowControl);
m_Serial->open(QIODevice::ReadWrite);
qDebug() << "SerialPort Status: " << m_Serial->isOpen();
emit serialConnected(m_Serial->isReadable());
while(!abort)
{
QThread::msleep(5);
while (!isConected(m_Serial)){
emit serialConnected(false);
isSerialConected = false;
QThread::sleep(1);
qDebug() << "Serial Error: ";
//qDebug() << "Is readable?: " << m_Serial->isReadable();
//qDebug() << "Bytes availiable?: " << m_Serial->bytesAvailable();
mutex.lock();
abort = _abort;
mutex.unlock();
}
if (!isSerialConected){
emit serialConnected(true);
isSerialConected=true;
}
mutex.lock();
abort = _abort;
mutex.unlock();
if(!m_outFrameQueue->isEmpty())
{
//qDebug() << "Frame empty";
{ *sendData*}
} else
{
if (m_Serial->waitForReadyRead(10) )
{ *readData*}
And the function that I am trying to use to detect if is actually connected:
bool SerialWorker::isConected(QSerialPort *m_Serial){
// qDebug() << "SerialPort Error: " << m_Serial->error();
// qDebug() << "SerialPort isReadable: " << m_Serial->isReadable();
// qDebug() << "SerialPort isReadable: " << m_Serial->bytesAvailable();
if (m_Serial->error() == QSerialPort::SerialPortError::NoError){
return true;
}
else if (m_Serial->error() == QSerialPort::SerialPortError::TimeoutError){
m_Serial->clearError();
//m_Serial->reset();
return true;
}else{
m_Serial->reset();
m_Serial->close();
m_Serial->clearError();
QThread::sleep(1);
m_Serial->open(QIODevice::ReadWrite);
return false;
}
}