How to read serial data from Qt5 - qt

Question

I am making a Qt5 an application to read data from the ESP32 microcontroller which I am programming with the Arduino framework using PlatformIO.
The problem I'm having is that I can't get the data to be received in uniform numbers of bytes. Sometimes I receive 1 byte, other times 2 bytes. Is this normal or is there a way to receive a complete buffer every time?
Qt Code:
void Dialog::on_connect_clicked()
{
if(esp_available){
esp->setPortName(espPortName);
esp->open(QSerialPort::ReadWrite);
esp->setBaudRate(9600);
esp->setDataBits(QSerialPort::Data8);
esp->setParity(QSerialPort::NoParity);
esp->setStopBits(QSerialPort::OneStop);
esp->setFlowControl(QSerialPort::NoFlowControl);
connect(esp, SIGNAL(readyRead()), this, SLOT(on_startStream_clicked()));
}
void Dialog::on_ledOn_clicked()
{
if(esp->isOpen()){
esp->write("1");
}
}
void Dialog::on_startStream_clicked()
{
QByteArray ba;
if(esp->isOpen()){
ba = esp->readAll();
qDebug() << ba;
}
}
Arduino Code:
#include <Arduino.h>
void setup()
{
Serial.begin(9600);
}
void loop()
{
while (Serial.available() > 0)
{
int val = Serial.read() - '0';
if (val == 1)
{
Serial.write("Hello");
}
}
Serial.flush();
}
Clicking the button 3 times sends the following output:
H
e
ll
o
H
e
l
lo
H
e
l
lo
What I would like to see in the output is either the individual characters, or the entire packet/buffer in one line,
Any suggestions?

Answer 1

It is normal to receive bytes of different sizes, in these cases a simple way to find a delimiter is better. For example in your case it is better to use endline ("\n") as delimiter:
Serial.println("Hello");
// or
// Serial.write("Hello\n");
void Dialog::on_startStream_clicked()
{
QByteArray ba;
while(esp->canReadLine()){
ba = esp->readLine();
qDebug() << ba;
}
}