QSerialPort Writing issue

Vishu1236

Hi,
I have written a simple serial port writing code as follows :```
//your code here

**#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtSerialPort/QSerialPort>
QSerialPort serial;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    serial.setPortName("com1");
    serial.open(QIODevice::ReadWrite);
    serial.setBaudRate(QSerialPort::Baud9600);
    serial.setDataBits(QSerialPort::Data8);
    serial.setParity(QSerialPort::NoParity);
    serial.setStopBits(QSerialPort::OneStop);
    serial.setFlowControl(QSerialPort::NoFlowControl);

    serial.write("OK");

}

my COM1 is connected to a hardware.
Now the issue is i am not able to recieve this data at hardware end, but if i am sending same data with different app like docklite , i am getting correct data at hardware end.
Also i am able to see this data in serial port monitor,but not at hardware end.
What can be the issue:

[Edit: fixed coding tags SGaist]

J.Hilk

@Vishu1236
two points.

first, set the settings of the serial port before you call open().
second open returns a bool if opening was successful or not. You should check that.

Vishu1236

Hi,
thanx for your reply
i have changed my code to :

//your code here

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtSerialPort/QSerialPort>
QSerialPort *serial;

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
serial = new QSerialPort(this);
serial->setPortName("com1");
connect(serial,SIGNAL(readyRead()),this,SLOT(serialReceived()));
serial->setBaudRate(QSerialPort::Baud9600);
serial->setDataBits(QSerialPort::Data8);
serial->setParity(QSerialPort::NoParity);
serial->setStopBits(QSerialPort::OneStop);
serial->setFlowControl(QSerialPort::NoFlowControl);
serial->open(QIODevice::WriteOnly);

serial->setDataTerminalReady(false);
if (serial->isOpen() && serial->isWritable())
{
    serial->write("OK");
}

}

still able to see data at serial port monitor but not at my harware.
serial port monitor is showing :

Port opened by process "serialport.exe" (PID: 8120)

Request: 11/12/2018 11:30:41 AM.24564 (+314.5910 seconds)

4F 4B OK

Port closed

Vishu1236

@J.Hilk
Hi
i tried printing errors and found "unknown error" errorno. 22 in setStopBits() ,setFlowControl.

any sugesstions??

SGaist

Hi,

22 ? It's not part of the QSerialPort:: SerialPortError enum values.