QtGui Serial Port & Arduino Serial Flow [SOLVED]

cherault

Hi All,

I am new on Qt, and I would like to build a simple project.
This project consists to READ the serial flow of an Arduino, which send two float values.
I would like to read these values through two LCD provided by Qt Creator and that's it !

I suppose it is possible...I read tons of informations, but I am unable to write the code.
Could you help me please ?

Thank you for your time and help.

Kind regards and cheers for this new year to you all.

Chris

kuzulis

Use QtSerialPort, read documentation, see examples.

cherault

Thanks Kuzulis for your reply.

I read the docs and examples, but it doesn't work for my case...
Anyway, I will try one more time to do the job.

Thanks again.

Regards,

SGaist

Hi and welcome to devnet,

Why doesn't it work for you case ?

Can you describe your setup ?

cherault

Hi SGait,

Thanks for your reply.

I don't really have problems, because today I am just learning Qt5.
It's a fantastic tool, but I am just a little bit disapointed when I saw all we need to do to just to print on a widget a serial flow...
It's amazing !

Well, I follow my search to see how to set my *.pro and the QSerial lib.

The main goal for me is pretty simple:

Sending some flow on the serial port /dev/tty (Linux) and show them through the widget LCD of Qt, and that's it :-)

Cheers,

SGaist

/dev/tty is generally not a serial port but the default console.

Then you didn't try to write it 100% natively ;)

I must say that it doesn't require that much:
QSerialPort + QLCDNumber and a slot for processing the data coming from your Arduino

cherault

Hi,

Thank you a lot, I will try it.

Have a nice day.

Cheers,

cherault

Hi,

Ok, I did some test, and this my files:

.pro

@
QT += core gui serialport

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = Pitot
TEMPLATE = app

SOURCES += main.cpp
mainwindow.cpp

HEADERS += mainwindow.h

FORMS += mainwindow.ui
@

This is the header file:
@#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private slots:

void on_lcdNumber_overflow();

private:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H
@

And the mainwindows.cpp:
@
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QSerialPort>
#include <QDebug>

QSerialPort serial;

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
serial= new QSerialPort(this);
serial->setPortName("/dev/ttyACM0");
serial->setBaudRate(QSerialPort::Baud9600);
serial->setDataBits(QSerialPort::Data8);
serial->setParity(QSerialPort::NoParity);
serial->setStopBits(QSerialPort::OneStop);
serial->setFlowControl(QSerialPort::NoFlowControl);
serial->open(QIODevice::ReadOnly);
connect(serial, SIGNAL(readyRead()),this,SLOT(serialReceived()));

}

MainWindow::~MainWindow()
{
delete ui;
serial->close();
}

void MainWindow::on_lcdNumber_overflow()
{
QByteArray qb;
qb=serial->readAll();
ui->lcdNumber->setDecMode(qb);
qDebug() << qb;
}
@

and the compilator says:

!file:///home/tux/Capture du 2014-12-26 10:18:28.png()!

cherault

Could you help me to solve this problem ?

Thanks in advance for your time and support.

Regards,

cherault

Ok, don't take in account my last post.
I solve a problem due to a pointer.

So, the only problem I have is the next, and this is the mainwindows.cpp:

@#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QSerialPort>
#include <QDebug>

QSerialPort *serial;

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
serial=new QSerialPort(this);
serial->setPortName("/dev/ttyACM0");
serial->setBaudRate(QSerialPort::Baud9600);
serial->setDataBits(QSerialPort::Data8);
serial->setParity(QSerialPort::NoParity);
serial->setStopBits(QSerialPort::OneStop);
serial->setFlowControl(QSerialPort::NoFlowControl);
serial->open(QIODevice::ReadOnly);
connect(serial, SIGNAL(readyRead()),this,SLOT(serialReceived()));

}

MainWindow::~MainWindow()
{
delete ui;
serial->close();
}

void MainWindow::on_lcdNumber_overflow()
{
QByteArray qb;
qb=serial->readAll();
ui->lcdNumber->setDecMode(qb);
qDebug() << qb;
}
@

So everything is fine but a line 35, I have a compilator problem.
It says:

/mainwindow.cpp:35: erreur : no matching function for call to 'QLCDNumber::setDecMode(QByteArray&)'
ui->lcdNumber->setDecMode(qb);
^
Could you tell me why it doesn't compile ?
I really don't understand.

Thanks for your help.

Regards,

cherault

Hi all,

Finally, I finished the job ! ;-)
The reason why I had some problems was the ByteArray, but now it works fine.
The modifications I did was:

void MainWindow::serialReceived()
{
QByteArray valeur;
valeur = serial->readAll();
float nb = valeur.toFloat();
ui->lcdNumber->display(nb);
}

And everythings lokk fine :-)

So thanks for your support.

Regards,

SGaist

Nice !

Since you have it working now, please update the thread title prepending [solved] so other forum users may know a solution has been found :)

Happy coding !