Qt 5.3 Can’t make QCompass (QSensor) work on Windows 8.1

[bestel74]

Hi everybody !

I put a copy on my post here because I don't know if it concern mobility or not : It don't work on Windows 8.1, but it's on a tablet, but it's on Windows 8.1... :)

I can't make sensors works on my Asus Transformer T100.

Magnetometer and Compass don't start, and I have fake value from the accelerometer (always x=0, y=9.8, z=0).

I always get the same result, even with my laptop :

@ven. juin 6 14:56:41 2014
Acceleration: x = 0
y = 9.8
z = 0

Compass: UNAVAILABLE
QMagnetometer: UNAVAILABLE@

And this code :

@QList<QByteArray> sensorList = QSensor::sensorTypes();
ui->init->append("Sensor list length: " + QString::number(sensorList.size()).toUtf8());
foreach( QByteArray sensorName, sensorList ) {
ui->init->append("Sensor: " + sensorName);
}@

Give me :

@Sensor: QAmbientLightSensor
Sensor: QAccelerometer
Sensor: QTiltSensor
Sensor: QOrientationSensor
Sensor: QRotationSensor@

Where is QCompass ? QMagnetometer ? Why QAccelerometer is faked ? :'(

Here is my simplified test-code, only with QCompass :

header:

@#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

#include <QCompass>
#include <QCompassReading>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

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

public slots:
void update();
void error(int);

private:
Ui::MainWindow *ui;

QCompass *compass;
QCompassReading *compass_reading;

};

#endif // MAINWINDOW_H@

code :

@#include <QDateTime>
#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QMessageBox>

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

ui->init->setText("Initialisation...");

compass = new QCompass(this);
connect(compass, SIGNAL(readingChanged()), this, SLOT(update()));
connect(compass, SIGNAL(sensorError(int)), this, SLOT(error(int)));
compass->setDataRate(1);
compass->start();
if (compass->isBusy()) {
    ui->init->append("QCompass is busy...");
}
if(compass->isConnectedToBackend()) {
    ui->init->append("QCompass is connected to backend...");
}
if(compass->isActive()) {
    ui->init->append("QCompass isActive...");
}

ui->init->append("Waiting for sensors...");

}

MainWindow::~MainWindow()
{
delete compass;
delete ui;
}

void MainWindow::update()
{
QString text_compass;

ui->textEdit->clear();

accel_reading = accel->reading();

compass_reading = compass->reading();
if(compass_reading != 0) {
    text_compass = QDateTime::currentDateTime().toString() +
            + "\nCompass:  azimuth = " + QString::number(compass_reading->azimuth());
            + "\ncalibration level = " + QString::number(compass_reading->calibrationLevel());

    ui->textEdit->append(text_compass);
}
else {
    text_compass = "\nCompass: UNAVAILABLE";
    ui->textEdit->append(text_compass);
}

}

void MainWindow::error(int erreur) {
QMessageBox::critical(this, "Erreur", "Erreur num : " + QString::number(erreur).toUtf8());
}@

My QCompass's never active / didn't start :(

[bestel74]

A new bug has been created : ref QTBUG-39590

The patch allow sensors to be used under a standard Windows desktop application.