undefined reference on qt sensor

hi everyone,
I am using qt android 5.1.1

and I have problem even I add sensors to pro file what is problem.

Thank you for any comment.

problem is :
../sensor_test/mainwindow.cpp:9: error: undefined reference to 'QAccelerometer::QAccelerometer(QObject*)'
../sensor_test/mainwindow.cpp:19: error: undefined reference to 'QSensor::QSensor(QByteArray const&, QObject*)'
../sensor_test/mainwindow.cpp:20: error: undefined reference to 'QSensor::start()'
../sensor_test/mainwindow.cpp:21: error: undefined reference to 'QSensor::reading() const'
Makefile:146: recipe for target 'libsensor_test.so' failed
../sensor_test/mainwindow.cpp:22: error: undefined reference to 'QSensor::~QSensor()'
../sensor_test/mainwindow.cpp:22: error: undefined reference to 'QSensor::~QSensor()'
collect2.exe: error: ld returned 1 exit status
my profile:

Code:

---

#-------------------------------------------------
#
# Project created by QtCreator 2013-08-30T14:44:53
#
#-------------------------------------------------
 
QT       += core gui
 
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 
TARGET = sensor_test
TEMPLATE = app
 
 
SOURCES += main.cpp\
        mainwindow.cpp
 
HEADERS  += mainwindow.h
 
FORMS    += mainwindow.ui
 
CONFIG += mobility
MOBILITY += sensors
 
OTHER_FILES += \
    android/AndroidManifest.xml \
    android/res/layout/splash.xml \
    android/res/values/libs.xml \
    android/res/values/strings.xml \
    android/res/values-de/strings.xml \
    android/res/values-el/strings.xml \
    android/res/values-es/strings.xml \
    android/res/values-et/strings.xml \
    android/res/values-fa/strings.xml \
    android/res/values-fr/strings.xml \
    android/res/values-id/strings.xml \
    android/res/values-it/strings.xml \
    android/res/values-ja/strings.xml \
    android/res/values-ms/strings.xml \
    android/res/values-nb/strings.xml \
    android/res/values-nl/strings.xml \
    android/res/values-pl/strings.xml \
    android/res/values-pt-rBR/strings.xml \
    android/res/values-ro/strings.xml \
    android/res/values-rs/strings.xml \
    android/res/values-ru/strings.xml \
    android/res/values-zh-rCN/strings.xml \
    android/res/values-zh-rTW/strings.xml \
    android/src/org/kde/necessitas/ministro/IMinistro.aidl \
    android/src/org/kde/necessitas/ministro/IMinistroCallback.aidl \
    android/src/org/qtproject/qt5/android/bindings/QtActivity.java \
    android/src/org/qtproject/qt5/android/bindings/QtApplication.java \
    android/version.xml

---

and my code:

Code:

---

#include "mainwindow.h"
#include "ui_mainwindow.h"
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ac=new QAccelerometer(this);
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::on_pushButton_clicked()
{
    QSensor sensor("QAccelerometer");
    sensor.start();
    QSensorReading *read=sensor.reading();
    ui->lineEdit->setText(read->property("x").value<QString>());
}

---