QLCDnumber, slots, and my own complete loss of mental function...

[Aesgarth]

@mrjj

yes please, i'll have a look at a sample and see if i can work it out.

[mrjj]

@Aesgarth
Hi
Here is a very basic sample.
I has LCD in mainwindow and pops a dialog where u can enter number to have it display that.
It as basic as it can get as i try to have as little code as possible to focus on the signal and slot thing.

Test Project
https://www.dropbox.com/s/u94zqx9v9c8xfdf/LCDOtherClass.zip?dl=0

(sorry its c++. I wish i could do python :)

Even its a MainWindow, the concept is 100% the same.
So slot in class that has LCD and signal in controller.

[Aesgarth]

@mrjj
Excellent, that helps... I think i understand what's going on there...
however.... this bit...

void MainWindow::on_pushButton_released()
{
    Dialog dia;
    connect( &dia, &Dialog::SetLCD, this, &MainWindow::SetLCD  );
    dia.exec();
}

i'm not sure where to put it in my version.

relaycontroller.h is where pretty much everything happens - switching of things and the counter...

#ifndef RELAYCONTROLLER_H
#define RELAYCONTROLLER_H

#include <QObject>
#include <QTimer>
#include <wiringPi.h>
#include <QDebug>

class RelayController : public QObject
{
    Q_OBJECT
public:
    explicit RelayController(int pin, int delay, QObject *parent = 0):QObject(parent){
        timer = new QTimer(this);
        state = false;
        timer->setInterval(delay);
        mPin = pin;
        //old style
        connect(timer, SIGNAL(timeout()), this, SLOT(onTimeout()));
        //new style
        //connect(timer, &QTimer::timeout, this, &RelayController::onTimeout);
        pinMode (mPin, OUTPUT);
        relayLow();
    }
    void start(){
        qDebug()<<"start";
        timer->start();
		//zero counter
		cntState = 0;
		//send to LCD
        emit setLCD(0);
    }
    void stop(){
        qDebug()<<"stop";
        timer->stop();
    }

    void relayLow(){
        digitalWrite (mPin, LOW);
        qDebug()<<"low";
    }
    void relayHigh(){
        //code here: relay on
        digitalWrite(mPin, HIGH);
        qDebug()<<"high";
    }
signals:
    void setLCD(int number);
	
private slots:
    void onTimeout(){
        if(state){
            relayHigh();
			//increment counter
			cntState++;
			//send to LCD
            emit setLCD(cntState);
			qDebug()<<cntState;
        }
        else
            relayLow();
        state = !state;
    }
private:
    QTimer *timer;
    bool state;
    int mPin;
	int cntState;
};


#endif // RELAYCONTROLLER_H

and RelayFrame is where the LCD is...

#include "relayframe.h"
#include "ui_relayframe.h"

#include <QPushButton>


//relayframe is a box with buttons and an LCD widget in it,
//created for each individual output pin. relayframe.ui is an XML
//file determining layout, code is in relayframe.h
RelayFrame::RelayFrame(int pin, QWidget *parent) :
    QFrame(parent),
    ui(new Ui::RelayFrame)
{
    ui->setupUi(this);
    //power cycle controller, 750ms delay
    controller = new RelayController(pin, 750);
    //heat cycle controller, 2 hour (5400000ms) delay
    controller2 = new RelayController(pin,5400000);
}

RelayFrame::~RelayFrame()
{
    delete ui;
}
// Power cycle button button
// While clicked controller initialised above, found in relaycontroller.h
// runs, when unchecked it stops (only one button per frame can be clicked
// at once, buttons auto toggle on)
void RelayFrame::on_powerBrtn_toggled(bool checked)
{
    if(checked)
        controller->start();
    else controller->stop();
}
// On button - turns on the pin relevant to this frame
void RelayFrame::on_onBtn_clicked()
{
    controller->relayHigh();
    //Set LCD to 1 while on...
    ui->lcdNumber->display(1);
}
// Off button - turns off the pin relevant to this frame
void RelayFrame::on_offBtn_clicked()
{
    controller->relayLow();
	ui->lcdNumber->display(0);
}
// Heat cycle button
// While clicked controller2 initialised above, found in relaycontroller.h
// runs, when unchecked it stops (only one button per frame can be clicked
// at once, buttons auto toggle on.
void RelayFrame::on_heatBtn_toggled(bool checked)
{
    if(checked)
        controller2->start();
    else controller2->stop();
}
//
void RelayFrame::SetLCD(int value) 
{
  ui->lcdNumber->display( QString::number(value)  );
}

This compiles and runs - but obviously as setLCD in the 2 places are not connected as yet the LCD number doesn't update...

Edit: there's something odd going on with the indentation when i copy and paste - but it looks ok before i do that, and seems to work. The last few lines of RelayFrame are where the relevant code is...

[mrjj]

Hi

the Dialog is the controller and
mainwindow is relayframe

RelayFrame::RelayFrame(int pin, QWidget *parent) :
    QFrame(parent),
    ui(new Ui::RelayFrame)
{
    ui->setupUi(this);

    controller = new RelayController(pin, 750);
// connect here !

    controller2 = new RelayController(pin,5400000);
// and HERE too

}

[Aesgarth]

@mrjj

OK, so i've probably done this wrong, but i have the following errors:

/home/pi/LampTesterV2/relayframe.cpp:17: error: ‘void RelayController::SetLCD(int)’ is protected within this context
  connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD  );
                            ^~~~~~

/home/pi/LampTesterV2/relayframe.cpp:17: error: no matching function for call to ‘RelayFrame::connect(void (RelayController::*)(int), RelayFrame*, void (RelayFrame::*)(int))’
  connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD  );
                                                               ^

in this bit...

RelayFrame::RelayFrame(int pin, QWidget *parent) :
    QFrame(parent),
    ui(new Ui::RelayFrame)
{
    ui->setupUi(this);
    //power cycle controller, 750ms delay
    controller = new RelayController(pin, 750);
	connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD  );
    //heat cycle controller, 2 hour (5400000ms) delay
    controller2 = new RelayController(pin,5400000);
	connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD  );
}

which doesn't look right to me anyway as i have the exact same thing twice...

[mrjj]

@Aesgarth

ahh c+11

change
signals:
to public signals:

i think

[Aesgarth]

@mrjj

That considerably reduced the error count, however....

/usr/include/qt4/QtCore/qobjectdefs.h:69: error: expected ‘:’ before ‘protected’
 #   define signals protected
                    ^

/home/pi/LampTesterV2/relaycontroller.h:47: in expansion of macro ‘signals’
 public signals:
        ^~~~~~~

Edited to include the next line.

[mrjj]

@Aesgarth

please look at sample. should be the same.

[Aesgarth]

@mrjj

I think the problem is with how i'm trying to connect the 2 - since using public signals: i get the same error with the connect lines commented out, but just using signals: (as per the example) works until i try to connect the signal and slot...

does this look right?
connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD);

[Aesgarth]

OK... i'm totally convinced the above is not right as i should be trying to connect the signal from controller or controller2 to the slot in RelayFrame, rather than the signal from RelayController...

[mrjj]

@Aesgarth
you miss the first part
connect(controller, &RelayController::SetLCD, this, &RelayFrame::SetLCD);
and
connect(controller2, &RelayController::SetLCD, this, &RelayFrame::SetLCD);

the syntax is

connect ( pointer to object, function address , pointer to object, function address )

(unless you are using lambdas)

[Aesgarth]

Thanks, that looks better but i'm back to

/home/pi/LampTesterV2/relayframe.cpp:17: error: ‘void RelayController::SetLCD(int)’ is protected within this context
  connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD  );
                            ^~~~~~

/home/pi/LampTesterV2/relayframe.cpp:17: error: no matching function for call to ‘RelayFrame::connect(void (RelayController::*)(int), RelayFrame*, void (RelayFrame::*)(int))’
  connect(&RelayController::SetLCD, this, &RelayFrame::SetLCD  );
                                                               ^

And i only have access to the device for the next hour, so... I think i'll have a bit of a practice at home over Christmas and see if i can improve any, and come back to this next year. Thanks for all the help @mrjj and @J.Hilk

[mrjj]

Hi
i think it says your RelayController::SetLCD is PROTECTED and not public.
Since you are in another class, you cant use a protected member.

Ok. we nail it in 2018 ;)