iot-sensortag: Allow reconnect after a failed connection attempt

A disconnected sensor tag can be tried to be reconnected by clicking
on the chart area or starting rescan from the Sensor settings menu.
During a (re)connection process a progress indicator is shown to
the user.

The user has a possibility to disconnect (and reconnect) a
currently connect SensorDataProvider

A new state, 'NotFound' is added in SensorTagDataProvider to
distinguish between states when a Sensor Tag has not been discovered
at all, and when it has already been discovered but is has been
disconnected.

Change-Id: I54eea72d8c92a67a5ccbb3bc192ac8f33ada1c39
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>

22 files changed, 561 insertions, 178 deletions

diff --git a/tradeshow/iot-sensortag/base.qrc b/tradeshow/iot-sensortag/base.qrc
index f0fddae..db038ef 100644
--- a/tradeshow/iot-sensortag/base.qrc
+++ b/tradeshow/iot-sensortag/base.qrc
@@ -21,5 +21,6 @@
         <file>resources/base/images/bg_blue.jpg</file>
         <file>resources/base/RotationPage.qml</file>
         <file>resources/base/AltitudeChart.qml</file>
+        <file>resources/base/BlinkingIcon.qml</file>
     </qresource>
 </RCC>
diff --git a/tradeshow/iot-sensortag/bluetoothdataprovider.cpp b/tradeshow/iot-sensortag/bluetoothdataprovider.cpp
index e3c746c..0987d0d 100644
--- a/tradeshow/iot-sensortag/bluetoothdataprovider.cpp
+++ b/tradeshow/iot-sensortag/bluetoothdataprovider.cpp
@@ -57,32 +57,42 @@ Q_DECLARE_LOGGING_CATEGORY(boot2QtDemos)
 
 BluetoothDataProvider::BluetoothDataProvider(QString id, QObject *parent)
     : SensorTagDataProvider(id, parent)
-    , activeDevice(Q_NULLPTR)
+    , m_btDevice(Q_NULLPTR)
     , m_smaSamples(0)
     , m_zeroAltitudeSamples(0)
     , gyroscopeX_calibration(0)
     , gyroscopeY_calibration(0)
     , gyroscopeZ_calibration(0)
 {
+    m_state = NotFound;
     intervalRotation = SENSORTAG_RAPID_TIMER_TIMEOUT_MS;
 }
 
 BluetoothDataProvider::~BluetoothDataProvider()
 {
-
+    if (m_btDevice)
+        delete m_btDevice;
 }
 
 bool BluetoothDataProvider::startDataFetching()
 {
     qCDebug(boot2QtDemos) << Q_FUNC_INFO;
-    if (activeDevice) {
-        connect(activeDevice, &BluetoothDevice::statusUpdated, this, [](const QString& statusMsg) { qCDebug(boot2QtDemos) << "----------" << statusMsg; });
-        connect(activeDevice, &BluetoothDevice::stateChanged, this, &BluetoothDataProvider::updateState);
-        connect(activeDevice, &BluetoothDevice::temperatureChanged, this, &BluetoothDataProvider::temperatureReceived);
-        connect(activeDevice, &BluetoothDevice::barometerChanged, this, &BluetoothDataProvider::barometerReceived);
-        connect(activeDevice, &BluetoothDevice::humidityChanged, this, &BluetoothDataProvider::humidityReceived);
-        connect(activeDevice, &BluetoothDevice::lightIntensityChanged, this, &BluetoothDataProvider::lightIntensityReceived);
-        connect(activeDevice, &BluetoothDevice::motionChanged, this, &BluetoothDataProvider::motionReceived);
+    if (m_btDevice) {
+        connect(m_btDevice, &BluetoothDevice::statusUpdated, this, [=](const QString& statusMsg) {
+            qCDebug(boot2QtDemos) << id() << "----------" << statusMsg;
+        });
+        connect(m_btDevice, &BluetoothDevice::stateChanged,
+                this, &BluetoothDataProvider::updateState);
+        connect(m_btDevice, &BluetoothDevice::temperatureChanged,
+                this, &BluetoothDataProvider::temperatureReceived);
+        connect(m_btDevice, &BluetoothDevice::barometerChanged,
+                this, &BluetoothDataProvider::barometerReceived);
+        connect(m_btDevice, &BluetoothDevice::humidityChanged,
+                this, &BluetoothDataProvider::humidityReceived);
+        connect(m_btDevice, &BluetoothDevice::lightIntensityChanged,
+                this, &BluetoothDataProvider::lightIntensityReceived);
+        connect(m_btDevice, &BluetoothDevice::motionChanged,
+                this, &BluetoothDataProvider::motionReceived);
         timer.setInterval(1000);
         timer.setSingleShot(true);
         connect(&timer, &QTimer::timeout, this, &BluetoothDataProvider::startServiceScan);
@@ -98,8 +108,10 @@ void BluetoothDataProvider::endDataFetching()
 void BluetoothDataProvider::startServiceScan()
 {
     qCDebug(boot2QtDemos)<<Q_FUNC_INFO;
-    if (activeDevice)
-        activeDevice->scanServices();
+    if (m_btDevice) {
+        setState(Scanning);
+        m_btDevice->scanServices();
+    }
 }
 
 void BluetoothDataProvider::temperatureReceived(double newAmbientTemperature, double newObjectTemperature)
@@ -213,9 +225,9 @@ QString BluetoothDataProvider::versionString() const
 
 void BluetoothDataProvider::updateState()
 {
-    switch (activeDevice->state()) {
+    switch (m_btDevice->state()) {
     case BluetoothDevice::Disconnected:
-        setState(Disconnected);
+        unbindDevice();
         break;
     case BluetoothDevice::Scanning:
         setState(Scanning);
@@ -262,11 +274,21 @@ void BluetoothDataProvider::recalibrateZeroAltitude()
 
 void BluetoothDataProvider::bindToDevice(BluetoothDevice *device)
 {
-    activeDevice = device;
-    startDataFetching();
+    if (m_btDevice)
+        delete m_btDevice;
+    m_btDevice = device;
+}
+
+void BluetoothDataProvider::unbindDevice()
+{
+    if (m_btDevice) {
+        delete m_btDevice;
+        m_btDevice = 0;
+        setState(NotFound);
+    }
 }
 
 BluetoothDevice *BluetoothDataProvider::device()
 {
-    return activeDevice;
+    return m_btDevice;
 }
diff --git a/tradeshow/iot-sensortag/bluetoothdataprovider.h b/tradeshow/iot-sensortag/bluetoothdataprovider.h
index f4c4b15..691b94c 100644
--- a/tradeshow/iot-sensortag/bluetoothdataprovider.h
+++ b/tradeshow/iot-sensortag/bluetoothdataprovider.h
@@ -70,6 +70,7 @@ public:
     QString versionString() const;
 
     void bindToDevice(BluetoothDevice *device);
+    void unbindDevice();
     BluetoothDevice* device();
 
 public slots:
@@ -88,7 +89,7 @@ protected:
 private:
     void updateState();
     float countRotationDegrees(double degreesPerSecond, quint64 milliseconds);
-    BluetoothDevice* activeDevice;
+    BluetoothDevice *m_btDevice;
     QTimer timer;
     int m_smaSamples;
     int m_zeroAltitudeSamples;
diff --git a/tradeshow/iot-sensortag/bluetoothdevice.cpp b/tradeshow/iot-sensortag/bluetoothdevice.cpp
index bc1fc0a..667e7a2 100644
--- a/tradeshow/iot-sensortag/bluetoothdevice.cpp
+++ b/tradeshow/iot-sensortag/bluetoothdevice.cpp
@@ -84,6 +84,17 @@ BluetoothDevice::BluetoothDevice()
 {
     m_lastMilliseconds = QDateTime::currentMSecsSinceEpoch();
     statusUpdated("Device created");
+
+    m_serviceDetailsTimer = new QTimer(this);
+    m_serviceDetailsTimer->setInterval(5000);
+    m_serviceDetailsTimer->setSingleShot(true);
+    connect(m_serviceDetailsTimer, &QTimer::timeout, [=]() {
+        qCDebug(boot2QtDemos) << "Service details timer timeout. No more services details found";
+        if (isDeviceReady())
+            setState(Connected);
+        else
+            setState(Disconnected);
+    });
 }
 
 BluetoothDevice::BluetoothDevice(const QBluetoothDeviceInfo &d)
@@ -94,8 +105,12 @@ BluetoothDevice::BluetoothDevice(const QBluetoothDeviceInfo &d)
 
 BluetoothDevice::~BluetoothDevice()
 {
-    delete m_controller;
+    if (m_controller) {
+        m_controller->disconnect();
+        delete m_controller;
+    }
 }
+
 QString BluetoothDevice::getAddress() const
 {
 #if defined(Q_OS_DARWIN)
@@ -114,6 +129,7 @@ QString BluetoothDevice::getName() const
 
 void BluetoothDevice::scanServices()
 {
+    setState(Scanning);
     if (!m_controller) {
         statusUpdated("(Connecting to device...)");
         // Connecting signals and slots for connecting to LE services.
@@ -131,6 +147,8 @@ void BluetoothDevice::scanServices()
 
         m_controller->setRemoteAddressType(QLowEnergyController::PublicAddress);
         m_controller->connectToDevice();
+    } else {
+        deviceConnected();
     }
 }
 
@@ -209,6 +227,8 @@ void BluetoothDevice::serviceScanDone()
 
     if (!m_motionService)
         qCDebug(boot2QtDemos) << "Motion service not found.";
+
+    m_serviceDetailsTimer->start();
 }
 
 void BluetoothDevice::temperatureDetailsDiscovered(QLowEnergyService::ServiceState newstate)
@@ -247,8 +267,7 @@ void BluetoothDevice::temperatureDetailsDiscovered(QLowEnergyService::ServiceSta
         }
 
         m_temperatureMeasurementStarted = true;
-        if (isDeviceReady())
-            setState(DeviceState::Connected);
+        m_serviceDetailsTimer->start();
     }
 }
 
@@ -287,8 +306,7 @@ void BluetoothDevice::barometerDetailsDiscovered(QLowEnergyService::ServiceState
         }
 
         m_barometerMeasurementStarted = true;
-        if (isDeviceReady())
-            setState(DeviceState::Connected);
+        m_serviceDetailsTimer->start();
     }
 }
 
@@ -328,8 +346,7 @@ void BluetoothDevice::humidityDetailsDiscovered(QLowEnergyService::ServiceState
         }
 
         m_humidityMeasurementStarted = true;
-        if (isDeviceReady())
-            setState(DeviceState::Connected);
+        m_serviceDetailsTimer->start();
     }
 }
 
@@ -369,8 +386,7 @@ void BluetoothDevice::lightIntensityDetailsDiscovered(QLowEnergyService::Service
         }
 
         m_lightIntensityMeasurementStarted = true;
-        if (isDeviceReady())
-            setState(DeviceState::Connected);
+        m_serviceDetailsTimer->start();
     }
 }
 
@@ -412,8 +428,7 @@ void BluetoothDevice::motionDetailsDiscovered(QLowEnergyService::ServiceState ne
             m_motionService->writeCharacteristic(characteristic, QByteArray::fromHex(SENSORTAG_RAPID_TIMER_TIMEOUT_STR), QLowEnergyService::WriteWithResponse);
         }
         m_motionMeasurementStarted = true;
-        if (isDeviceReady())
-            setState(DeviceState::Connected);
+        m_serviceDetailsTimer->start();
     }
 }
 
@@ -461,10 +476,14 @@ double BluetoothDevice::convertIrTemperatureAPIReadingToCelsius(quint16 rawReadi
 
 bool BluetoothDevice::isDeviceReady() const
 {
-    return m_temperatureMeasurementStarted
-        && m_humidityMeasurementStarted
-        && m_lightIntensityMeasurementStarted
-        && m_motionMeasurementStarted;
+    if (m_temperatureMeasurementStarted
+            || m_barometerMeasurementStarted
+            || m_humidityMeasurementStarted
+            || m_lightIntensityMeasurementStarted
+            || m_motionMeasurementStarted) {
+        return true;
+    }
+    return false;
 }
 
 void BluetoothDevice::irTemperatureReceived(const QByteArray &value)
@@ -552,9 +571,13 @@ void BluetoothDevice::motionReceived(const QByteArray &value)
 
 void BluetoothDevice::deviceConnected()
 {
-    setState(DeviceState::Scanning);
-    statusUpdated("(Discovering services...)");
-    m_controller->discoverServices();
+    if (isDeviceReady()) {
+        setState(Connected);
+    } else {
+        setState(DeviceState::Scanning);
+        statusUpdated("(Discovering services...)");
+        m_controller->discoverServices();
+    }
 }
 
 void BluetoothDevice::errorReceived(QLowEnergyController::Error /*error*/)
diff --git a/tradeshow/iot-sensortag/bluetoothdevice.h b/tradeshow/iot-sensortag/bluetoothdevice.h
index 1a37448..6a75a67 100644
--- a/tradeshow/iot-sensortag/bluetoothdevice.h
+++ b/tradeshow/iot-sensortag/bluetoothdevice.h
@@ -185,6 +185,8 @@ private:
     QBluetoothDeviceInfo m_deviceInfo;
 
     SensorTagDataProvider *m_dataProvider;
+
+    QTimer *m_serviceDetailsTimer;
 };
 
 #endif // BLUETOOTHBLUETOOTHDEVICE_H
diff --git a/tradeshow/iot-sensortag/dataproviderpool.cpp b/tradeshow/iot-sensortag/dataproviderpool.cpp
index 040809d..77c4514 100644
--- a/tradeshow/iot-sensortag/dataproviderpool.cpp
+++ b/tradeshow/iot-sensortag/dataproviderpool.cpp
@@ -84,6 +84,11 @@ SensorTagDataProvider *DataProviderPool::getProvider(SensorTagDataProvider::TagT
     return p;
 }
 
+void DataProviderPool::disconnectProvider(QString id)
+{
+    Q_UNUSED(id)
+}
+
 QQmlListProperty<SensorTagDataProvider> DataProviderPool::dataProviders()
 {
    return QQmlListProperty<SensorTagDataProvider>(this, m_dataProviders);
diff --git a/tradeshow/iot-sensortag/dataproviderpool.h b/tradeshow/iot-sensortag/dataproviderpool.h
index e8d50e6..9c14504 100644
--- a/tradeshow/iot-sensortag/dataproviderpool.h
+++ b/tradeshow/iot-sensortag/dataproviderpool.h
@@ -65,6 +65,7 @@ public:
     Q_INVOKABLE virtual void startScanning();
     Q_INVOKABLE virtual void stopScanning();
     Q_INVOKABLE virtual SensorTagDataProvider* getProvider(SensorTagDataProvider::TagType type) const;
+    Q_INVOKABLE virtual void disconnectProvider(QString id);
 
     QQmlListProperty<SensorTagDataProvider> dataProviders();
 
@@ -75,6 +76,7 @@ signals:
     void providerDisconnected(QString id);
     void providerInError(QString id);
     void providersUpdated();
+    void scanStarted();
     void scanFinished();
     void providerForCloudChanged();
     void dataProvidersChanged();
diff --git a/tradeshow/iot-sensortag/demodataproviderpool.cpp b/tradeshow/iot-sensortag/demodataproviderpool.cpp
index ccaf7fd..92c5e41 100644
--- a/tradeshow/iot-sensortag/demodataproviderpool.cpp
+++ b/tradeshow/iot-sensortag/demodataproviderpool.cpp
@@ -49,6 +49,7 @@
 ****************************************************************************/
 #include "demodataproviderpool.h"
 #include "mockdataprovider.h"
+#include "bluetoothdataprovider.h"
 
 DemoCloudProvider::DemoCloudProvider(QObject *parent)
     : SensorTagDataProvider(parent)
@@ -261,15 +262,16 @@ DemoDataProviderPool::DemoDataProviderPool(QObject *parent)
     : SensorTagDataProviderPool("Demo", parent)
     , m_mockData(false)
     , m_cloudProvider(0)
+    , m_initialized(false)
 {
 }
 
 void DemoDataProviderPool::startScanning()
 {
-    qDeleteAll(m_dataProviders);
-    m_dataProviders.clear();
-
     if (m_mockData) {
+        qDeleteAll(m_dataProviders);
+        m_dataProviders.clear();
+
         MockDataProvider* p = new MockDataProvider("MOCK_PROVIDER_1", this);
         p->setTagType(SensorTagDataProvider::ObjectTemperature | SensorTagDataProvider::AmbientTemperature | SensorTagDataProvider::Rotation);
         m_dataProviders.push_back(p);
@@ -287,6 +289,42 @@ void DemoDataProviderPool::startScanning()
         finishScanning();
     }
     else {
+        if (!m_initialized) {
+            // Create a DataProvider objects early on for UI to be able to
+            // show all data providers as available. The BT device information
+            // will be added later on when the Bluetooth device has been found
+            for (const QString& id : m_macFilters) {
+                BluetoothDataProvider *p = new BluetoothDataProvider(id, this);
+                m_dataProviders.push_back(p);
+            }
+            // Fake that we have set of sensors with different capabilities
+            // by removing some of the sensor data types from each sensor tag
+            if (m_dataProviders.length() > 0) {
+                SensorTagDataProvider *p = m_dataProviders.at(0);
+                p->setTagType(SensorTagDataProvider::ObjectTemperature |
+                              SensorTagDataProvider::Light |
+                              SensorTagDataProvider::Magnetometer |
+                              SensorTagDataProvider::Accelometer);
+                emit dataProvidersChanged();
+                if (m_dataProviders.length() > 1) {
+                    p = m_dataProviders.at(1);
+                    p->setTagType(SensorTagDataProvider::AmbientTemperature |
+                                  SensorTagDataProvider::Altitude |
+                                  SensorTagDataProvider::Humidity |
+                                  SensorTagDataProvider::Rotation |
+                                  SensorTagDataProvider::AirPressure);
+                    emit dataProvidersChanged();
+                }
+            }
+            m_initialized = true;
+        }
+        // Set initial state to Scanning for UI to be
+        // able to show "Connecting.." information
+        for (SensorTagDataProvider *p : m_dataProviders) {
+            if (p->state() == SensorTagDataProvider::NotFound) {
+                p->setState(SensorTagDataProvider::Scanning);
+            }
+        }
         SensorTagDataProviderPool::startScanning();
     }
 }
@@ -299,25 +337,13 @@ void DemoDataProviderPool::finishScanning()
         m_cloudProvider = m_dataProviders.at(0);
         emit providerForCloudChanged();
     } else {
-        // Fake that we have set of sensors with different capabilities
-        // by removing some of the sensor data types from each sensor tag
-        for (SensorTagDataProvider *p : m_dataProviders) {
-            if (p->id() == QStringLiteral("A0:E6:F8:B6:5B:86")) {
-                p->setTagType(SensorTagDataProvider::ObjectTemperature |
-                              SensorTagDataProvider::Light |
-                              SensorTagDataProvider::Magnetometer |
-                              SensorTagDataProvider::Accelometer);
-            }
-            else if (p->id() == QStringLiteral("A0:E6:F8:B6:44:01")) {
-                p->setTagType(SensorTagDataProvider::AmbientTemperature |
-                              SensorTagDataProvider::Altitude |
-                              SensorTagDataProvider::Humidity |
-                              SensorTagDataProvider::Rotation |
-                              SensorTagDataProvider::AirPressure);
-            }
-        }
         m_cloudProvider = new DemoCloudProvider(this);
         static_cast<DemoCloudProvider*>(m_cloudProvider)->setDataProviders(m_dataProviders);
+        for (SensorTagDataProvider *p : m_dataProviders) {
+            // If BluetoothDevice object is not attached, the device has not been found
+            if (!static_cast<BluetoothDataProvider*>(p)->device())
+                p->setState(SensorTagDataProvider::NotFound);
+        }
     }
     emit dataProvidersChanged();
     emit scanFinished();
@@ -332,4 +358,3 @@ SensorTagDataProvider *DemoDataProviderPool::providerForCloud() const
 {
     return m_cloudProvider;
 }
-
diff --git a/tradeshow/iot-sensortag/demodataproviderpool.h b/tradeshow/iot-sensortag/demodataproviderpool.h
index 24a2136..7d2e939 100644
--- a/tradeshow/iot-sensortag/demodataproviderpool.h
+++ b/tradeshow/iot-sensortag/demodataproviderpool.h
@@ -70,9 +70,9 @@ protected:
     void finishScanning() override;
 
 private:
-
     bool m_mockData;
     SensorTagDataProvider* m_cloudProvider;
+    bool m_initialized;
 };
 
 // Internal class to provide sensor data for cloud update from demo setup
diff --git a/tradeshow/iot-sensortag/main.cpp b/tradeshow/iot-sensortag/main.cpp
index f2cf849..0925a5a 100644
--- a/tradeshow/iot-sensortag/main.cpp
+++ b/tradeshow/iot-sensortag/main.cpp
@@ -110,10 +110,10 @@ int main(int argc, char *argv[])
     else if (sensorSource == QString("sensor").toLower()) {
         qCDebug(boot2QtDemos) << "Running in sensor mode";
         dataProviderPool = new DemoDataProviderPool;
-        // List of devices used at EW: "A0:E6:F8:B6:44:01", "A0:E6:F8:B6:5B:86"
+        // List of devices used in Embedded World
         static_cast<SensorTagDataProviderPool*>(dataProviderPool)->setMacFilterList(QStringList() <<
-                                                                                    "A0:E6:F8:B6:44:01" <<
-                                                                                    "A0:E6:F8:B6:5B:86");
+                                                                                    "24:71:89:BF:3B:82" <<
+                                                                                    "24:71:89:BC:44:82");
     }
 #endif
     else if (sensorSource == QString("mock").toLower()){
diff --git a/tradeshow/iot-sensortag/mockdataprovider.cpp b/tradeshow/iot-sensortag/mockdataprovider.cpp
index 4991e43..060cd70 100644
--- a/tradeshow/iot-sensortag/mockdataprovider.cpp
+++ b/tradeshow/iot-sensortag/mockdataprovider.cpp
@@ -238,6 +238,11 @@ void MockDataProvider::rapidTimerExpired()
     emit gyroscopeDegPerSecChanged();
 }
 
+void MockDataProvider::startServiceScan()
+{
+
+}
+
 void MockDataProvider::reset()
 {
     rotation_x = 0;
diff --git a/tradeshow/iot-sensortag/mockdataprovider.h b/tradeshow/iot-sensortag/mockdataprovider.h
index 7f2c032..0a2ee19 100644
--- a/tradeshow/iot-sensortag/mockdataprovider.h
+++ b/tradeshow/iot-sensortag/mockdataprovider.h
@@ -71,6 +71,7 @@ public:
 public slots:
     void slowTimerExpired();
     void rapidTimerExpired();
+    void startServiceScan();
 
 protected:
     void reset() override;
diff --git a/tradeshow/iot-sensortag/resources/base/BaseChart.qml b/tradeshow/iot-sensortag/resources/base/BaseChart.qml
index 58549b5..d144916 100644
--- a/tradeshow/iot-sensortag/resources/base/BaseChart.qml
+++ b/tradeshow/iot-sensortag/resources/base/BaseChart.qml
@@ -61,9 +61,17 @@ Item {
     property bool rightSide: false
     property alias titlePaneHeight: titleIcon.height
     property bool hasData: baseChart.sensor ? baseChart.sensor.state === SensorTagData.Connected : false
+    property int sensorState: sensor ? sensor.state : SensorTagData.NotFound
 
     signal clicked
 
+    onSensorStateChanged: {
+        if (sensorState === SensorTagData.Scanning)
+            sensorIcon.startBlinking();
+        else
+            sensorIcon.stopBlinking();
+    }
+
     Image {
         id: titleIcon
 
@@ -89,6 +97,42 @@ Item {
         anchors.bottomMargin: 16
         anchors.left: parent.left
         anchors.right: parent.right
+        visible: sensorState === SensorTagData.Connected
+    }
+
+    Item {
+        anchors.top: titleIcon.bottom
+        anchors.bottom: separator.bottom
+        anchors.bottomMargin: 16
+        anchors.left: parent.left
+        anchors.right: parent.right
+        visible: sensorState === SensorTagData.Scanning ||
+                 sensorState === SensorTagData.Disconnected ||
+                 sensorState === SensorTagData.Error ||
+                 sensorState === SensorTagData.NotFound
+
+        Column {
+            anchors.centerIn: parent
+            spacing: 20
+
+            BlinkingIcon {
+                id: sensorIcon
+
+                source: pathPrefix + "Toolbar/icon_topbar_sensor.png"
+                anchors.horizontalCenter: parent.horizontalCenter
+                visible: sensorState === SensorTagData.Scanning
+            }
+
+            Text {
+                id: stateText
+
+                color: "white"
+                text: sensorState === SensorTagData.Scanning ? "Connecting to sensor..."
+                        : sensorState === SensorTagData.Disconnected ? "Disconnected"
+                        : sensorState === SensorTagData.NotFound ? "Device not found"
+                        : ""
+            }
+        }
     }
 
     Image {
diff --git a/tradeshow/iot-sensortag/resources/base/BlinkingIcon.qml b/tradeshow/iot-sensortag/resources/base/BlinkingIcon.qml
new file mode 100644
index 0000000..fc29fc9
--- /dev/null
+++ b/tradeshow/iot-sensortag/resources/base/BlinkingIcon.qml
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of Qt for Device Creation.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+import QtQuick 2.0
+
+Image {
+    id: icon
+
+    property bool activeBlink: false
+
+    function startBlinking() {
+        if (!activeBlink) {
+            activeBlink = true;
+            mainWindow.startBlink();
+        }
+    }
+
+    function stopBlinking() {
+        if (activeBlink) {
+            activeBlink = false;
+            mainWindow.stopBlink();
+        }
+    }
+
+    opacity: activeBlink ? mainWindow.globalBlinkOpacity: 1
+}
diff --git a/tradeshow/iot-sensortag/resources/base/RotationPage.qml b/tradeshow/iot-sensortag/resources/base/RotationPage.qml
index 347a886..eee47c1 100644
--- a/tradeshow/iot-sensortag/resources/base/RotationPage.qml
+++ b/tradeshow/iot-sensortag/resources/base/RotationPage.qml
@@ -56,55 +56,101 @@ Item {
     property var sensor
     property var rotationUpdateInterval: sensor ? sensor.rotationUpdateInterval : 0
 
-    focus: true
+    property int sensorState: sensor ? sensor.state : SensorTagData.Disconnected
 
-    Image {
-        id: ring
-        anchors.centerIn: parent
-        source: pathPrefix + "Gyro/gyro_outer.png"
+    onSensorStateChanged: {
+        if (sensorState === SensorTagData.Scanning)
+            sensorIcon.startBlinking();
+        else
+            sensorIcon.stopBlinking();
     }
-    Image {
-        id: outerRing
-        anchors.centerIn: parent
-        source: pathPrefix + "Gyro/gyro_ring3.png"
-        rotation: sensor ? sensor.rotationX : 0
-        Behavior on rotation {
-            RotationAnimator {
-                easing.type: Easing.Linear
-                duration: rotationUpdateInterval
-                direction: RotationAnimator.Shortest
+
+    Item {
+        anchors.fill: parent
+
+        visible: sensorState === SensorTagData.Connected
+
+        Image {
+            id: ring
+            anchors.centerIn: parent
+            source: pathPrefix + "Gyro/gyro_outer.png"
+        }
+        Image {
+            id: outerRing
+            anchors.centerIn: parent
+            source: pathPrefix + "Gyro/gyro_ring3.png"
+            rotation: sensor ? sensor.rotationX : 0
+            Behavior on rotation {
+                RotationAnimator {
+                    easing.type: Easing.Linear
+                    duration: rotationUpdateInterval
+                    direction: RotationAnimation.Shortest
+                }
             }
         }
-    }
-    Image {
-        id: largeRing
-        anchors.centerIn: parent
-        source: pathPrefix + "Gyro/gyro_ring2.png"
-        rotation: sensor ? sensor.rotationY : 0
-        Behavior on rotation {
-            RotationAnimator {
-                easing.type: Easing.Linear
-                duration: rotationUpdateInterval
-                direction: RotationAnimator.Shortest
+        Image {
+            id: largeRing
+            anchors.centerIn: parent
+            source: pathPrefix + "Gyro/gyro_ring2.png"
+            rotation: sensor ? sensor.rotationY : 0
+            Behavior on rotation {
+                RotationAnimator {
+                    easing.type: Easing.Linear
+                    duration: rotationUpdateInterval
+                    direction: RotationAnimation.Shortest
+                }
             }
         }
-    }
-    Image {
-        id: mediumRing
-        anchors.centerIn: parent
-        source: pathPrefix + "Gyro/gyro_ring1.png"
-        rotation: sensor ? sensor.rotationZ : 0
-        Behavior on rotation {
-            RotationAnimator {
-                easing.type: Easing.Linear
-                duration: rotationUpdateInterval
-                direction: RotationAnimator.Shortest
+        Image {
+            id: mediumRing
+            anchors.centerIn: parent
+            source: pathPrefix + "Gyro/gyro_ring1.png"
+            rotation: sensor ? sensor.rotationZ : 0
+            Behavior on rotation {
+                RotationAnimator {
+                    easing.type: Easing.Linear
+                    duration: rotationUpdateInterval
+                    direction: RotationAnimation.Shortest
+                }
             }
         }
+        Image {
+            id: centerRing
+            anchors.centerIn: parent
+            source: pathPrefix + "Gyro/gyro_center.png"
+        }
     }
-    Image {
-        id: centerRing
-        anchors.centerIn: parent
-        source: pathPrefix + "Gyro/gyro_center.png"
+
+    Item {
+        id: connectingNote
+
+        anchors.fill: parent
+        visible: sensorState === SensorTagData.Scanning ||
+                 sensorState === SensorTagData.Disconnected ||
+                 sensorState === SensorTagData.Error ||
+                 sensorState === SensorTagData.NotFound
+
+        Column {
+            anchors.centerIn: parent
+            spacing: 20
+
+            BlinkingIcon {
+                id: sensorIcon
+
+                source: pathPrefix + "Toolbar/icon_topbar_sensor.png"
+                anchors.horizontalCenter: parent.horizontalCenter
+                visible: sensorState === SensorTagData.Scanning
+            }
+
+            Text {
+                id: stateText
+
+                color: "white"
+                text: sensorState === SensorTagData.Scanning ? "Connecting to sensor..."
+                        : sensorState === SensorTagData.Disconnected ? "Disconnected"
+                        : sensorState === SensorTagData.NotFound ? "Device not found"
+                        : ""
+            }
+        }
     }
 }
diff --git a/tradeshow/iot-sensortag/resources/base/SensorSettings.qml b/tradeshow/iot-sensortag/resources/base/SensorSettings.qml
index a2a8202..5aace2c 100644
--- a/tradeshow/iot-sensortag/resources/base/SensorSettings.qml
+++ b/tradeshow/iot-sensortag/resources/base/SensorSettings.qml
@@ -57,8 +57,8 @@ Rectangle {
 
     property alias listModelCount: list.count
 
-    width: 360
-    height: 252
+    width: 620
+    height: 480
     color: "black"
 
     Text {
@@ -73,68 +73,129 @@ Rectangle {
 
     Image {
         id: icon
-        width: 60
-        height: 60
+
         anchors.top: titleText.bottom
         anchors.horizontalCenter: parent.horizontalCenter
         anchors.margins: 8
         source: pathPrefix + "Toolbar/icon_topbar_sensor.png"
-
-        MouseArea {
-            anchors.fill: parent
-            onClicked: dataProviderPool.startScanning()
-        }
     }
 
     ListView {
         id: list
         anchors.top: icon.bottom
         anchors.topMargin: 16
-        height: 150
-        width: parent.width
-        clip: true
+        anchors.left: parent.left
+        anchors.leftMargin: 30
+        anchors.right: parent.right
+        anchors.rightMargin: 30
         orientation: ListView.Horizontal
         model: dataProviderPool.dataProviders
+        height: parent.height
+        clip: true
+        snapMode: ListView.SnapToItem
+        boundsBehavior: Flickable.StopAtBounds
+
+        function getTagTypeStr(tagType) {
+            var tagStr = "";
+            if (tagType & SensorTagData.AmbientTemperature)
+                tagStr += "Ambient Temperature\n";
+            if (tagType & SensorTagData.ObjectTemperature)
+                tagStr += "Object Temperature\n";
+            if (tagType & SensorTagData.Humidity)
+                tagStr += "Humidity\n";
+            if (tagType & SensorTagData.Altitude)
+                tagStr += "Altitude\n";
+            if (tagType & SensorTagData.Light)
+                tagStr += "Light\n";
+            if (tagType & SensorTagData.Rotation)
+                tagStr += "Gyroscope\n";
+            if (tagType & SensorTagData.Magnetometer)
+                tagStr += "Magnetometer\n";
+            if (tagType & SensorTagData.Accelometer)
+                tagStr += "Accelometer\n";
+
+            return tagStr;
+        }
 
         delegate: Item {
             id: listItem
             width: mainRect.width / 3
+            height: childrenRect.height
+
             ColumnLayout {
                 spacing: 8
-                Item {
-                    width: listItem.width
-                    height: 40
-                    Text {
-                        anchors.top: parent.top
-                        anchors.left: parent.left
-                        anchors.right: parent.right
-                        anchors.margins: 4
-                        horizontalAlignment: Text.AlignHCenter
-                        text: providerId.toUpperCase()
-                        color: "white"
-                        font.pixelSize: 16
-                        elide: Text.ElideMiddle
-                        clip: true
-                    }
+
+                Text {
+                    anchors.top: parent.top
+                    anchors.left: parent.left
+                    anchors.right: parent.right
+                    horizontalAlignment: Text.AlignHCenter
+                    text: providerId
+                    color: "white"
+                    font.pixelSize: 16
+                    elide: Text.ElideMiddle
                 }
-                Image {
-                    Layout.alignment: Qt.AlignHCenter
-                    width: 40
-                    height: 40
+
+                BlinkingIcon {
+                    id: sensorIcon
+
+                    property bool canBlink: modelData.state === SensorTagData.Scanning
+
+                    onCanBlinkChanged: {
+                            if (canBlink)
+                                sensorIcon.startBlinking();
+                             else
+                                sensorIcon.stopBlinking();
+                    }
+
                     source: pathPrefix + "Toolbar/icon_topbar_sensor.png"
-                    opacity: (modelData.state === SensorTagData.Connected
-                             || modelData.state === SensorTagData.Scanning) ? 1 : 0.5
+                    anchors.horizontalCenter: parent.horizontalCenter
+
+                    Component.onDestruction: {
+                        sensorIcon.stopBlinking()
+                    }
+
+                    MouseArea {
+                        anchors.fill: parent
+                        onClicked: {
+                            if (modelData.state === SensorTagData.Connected)
+                                dataProviderPool.disconnectProvider(modelData.providerId);
+                            else if (modelData.state === SensorTagData.NotFound)
+                                dataProviderPool.startScanning();
+                            else if (modelData.state === SensorTagData.Scanning)
+                                dataProviderPool.disconnectProvider(modelData.providerId)
+                            else
+                                modelData.startServiceScan();
+                        }
+                    }
                 }
 
                 Text {
                     Layout.alignment: Qt.AlignHCenter
-                    text: modelData.state === SensorTagData.Disconnected ? "Disconnected"
-                          : (modelData.state === SensorTagData.Scanning) ? "Scanning"
-                          : (modelData.state === SensorTagData.Connected) ? "Connected"
+                    text: modelData.state === SensorTagData.NotFound ? "\nNOT FOUND"
+                          : (modelData.state === SensorTagData.Disconnected) ? "\nDISCONNECTED"
+                          : (modelData.state === SensorTagData.Scanning) ? "\nCONNECTING"
+                          : (modelData.state === SensorTagData.Connected) ? "\nCONNECTED"
                           : "Error"
                     color: "white"
                     font.pixelSize: 14
                 }
+
+                Item {
+                    height: 30
+                    width: 10
+                }
+
+                Text {
+                    color: "white"
+                    text: "Provides data for:"
+                }
+
+                Text {
+                    color: "white"
+                    lineHeight: 0.7
+                    text: list.getTagTypeStr(modelData.tagType())
+                }
             }
         }
     }
diff --git a/tradeshow/iot-sensortag/resources/base/main.qml b/tradeshow/iot-sensortag/resources/base/main.qml
index c55d8ee..2840433 100644
--- a/tradeshow/iot-sensortag/resources/base/main.qml
+++ b/tradeshow/iot-sensortag/resources/base/main.qml
@@ -58,6 +58,7 @@ Window {
     property alias contentFile: contentLoader.source
     property DataProviderPool dataProviderPool
     property SeriesStorage seriesStorage
+    property real globalBlinkOpacity: 1.0
 
     // Size defaults to the small display
     width: 1920
@@ -76,4 +77,40 @@ Window {
         anchors.fill: parent
         anchors.centerIn: parent
     }
+
+
+
+    function startBlink() {
+        flash.blinkers++;
+    }
+
+    function stopBlink() {
+        flash.blinkers--;
+    }
+
+    // Animation to allow synchronized
+    // blinking of BlinkingIcons
+    SequentialAnimation {
+        id: flash
+
+        property int blinkers: 0
+
+        running: blinkers
+        loops: Animation.Infinite
+        alwaysRunToEnd: true
+
+        PropertyAnimation {
+            target: mainWindow
+            property: "globalBlinkOpacity"
+            to: 0.3
+            duration: 700
+        }
+
+        PropertyAnimation {
+            target: mainWindow
+            property: "globalBlinkOpacity"
+            to: 1
+            duration: 700
+        }
+    }
 }
diff --git a/tradeshow/iot-sensortag/resources/small/MainSmall.qml b/tradeshow/iot-sensortag/resources/small/MainSmall.qml
index df4a868..83835e3 100644
--- a/tradeshow/iot-sensortag/resources/small/MainSmall.qml
+++ b/tradeshow/iot-sensortag/resources/small/MainSmall.qml
@@ -54,25 +54,31 @@ import "../base"
 Item {
     id: main
 
+    function startRescan(sensor) {
+        if (sensor.state === SensorTagData.NotFound)
+            dataProviderPool.startScanning();
+        else if (sensor.state === SensorTagData.Scanning)
+            dataProviderPool.disconnectProvider(sensor.providerId)
+        else if (sensor.state !== SensorTagData.Connected)
+            sensor.startServiceScan();
+    }
+
     anchors.fill: parent
 
     Component.onCompleted: {
-        dataProviderPool.startScanning()
-    }
-
-    Connections {
-        target: dataProviderPool
-        onScanFinished: {
-            ambientTemp.sensor = dataProviderPool.getProvider(SensorTagData.AmbientTemperature);
-            objectTemp.sensor = dataProviderPool.getProvider(SensorTagData.ObjectTemperature);
-            humidity.sensor = dataProviderPool.getProvider(SensorTagData.Humidity);
-            airPressure.sensor = dataProviderPool.getProvider(SensorTagData.AirPressure);
-            light.sensor = dataProviderPool.getProvider(SensorTagData.Light);
-            magnetometer.sensor = dataProviderPool.getProvider(SensorTagData.Magnetometer);
-            rotation.sensor = dataProviderPool.getProvider(SensorTagData.Rotation);
-            accelometer.sensor = dataProviderPool.getProvider(SensorTagData.Accelometer);
-            rotationMain.sensor = dataProviderPool.getProvider(SensorTagData.Rotation);
-        }
+        dataProviderPool.startScanning();
+
+        // UI gets information about the intended setup of the
+        // sensor even though they have not been really discovered yet
+        ambientTemp.sensor = dataProviderPool.getProvider(SensorTagData.AmbientTemperature);
+        objectTemp.sensor = dataProviderPool.getProvider(SensorTagData.ObjectTemperature);
+        humidity.sensor = dataProviderPool.getProvider(SensorTagData.Humidity);
+        airPressure.sensor = dataProviderPool.getProvider(SensorTagData.AirPressure);
+        light.sensor = dataProviderPool.getProvider(SensorTagData.Light);
+        magnetometer.sensor = dataProviderPool.getProvider(SensorTagData.Magnetometer);
+        rotation.sensor = dataProviderPool.getProvider(SensorTagData.Rotation);
+        accelometer.sensor = dataProviderPool.getProvider(SensorTagData.Accelometer);
+        rotationMain.sensor = dataProviderPool.getProvider(SensorTagData.Rotation);
     }
 
     Column {
@@ -92,6 +98,7 @@ Item {
 
             width: leftPane.width
             height: leftPane.indicatorHeight
+            onClicked: main.startRescan(sensor)
         }
 
         ObjectTemperatureChart {
@@ -99,6 +106,7 @@ Item {
 
             width: leftPane.width
             height: leftPane.indicatorHeight
+            onClicked: main.startRescan(sensor)
         }
 
         HumidityChart {
@@ -106,6 +114,7 @@ Item {
 
             width: leftPane.width
             height: leftPane.indicatorHeight
+            onClicked: main.startRescan(sensor)
        }
 
         AltitudeChart {
@@ -113,6 +122,7 @@ Item {
 
             width: leftPane.width
             height: leftPane.indicatorHeight
+            onClicked: main.startRescan(sensor)
         }
     }
 
@@ -131,6 +141,7 @@ Item {
 
             width: rightPane.width
             height: rightPane.height / 4
+            onClicked: main.startRescan(sensor)
         }
 
         MagnetometerChart {
@@ -138,6 +149,7 @@ Item {
 
             width: rightPane.width
             height: rightPane.height * 0.3 - 30
+            onClicked: main.startRescan(sensor)
         }
 
         GyroChart {
@@ -145,6 +157,7 @@ Item {
 
             width: rightPane.width
             height: rightPane.height * 0.3 - 60
+            onClicked: main.startRescan(sensor)
         }
 
         AccelChart {
@@ -152,6 +165,7 @@ Item {
 
             width: rightPane.width
             height: rightPane.height - light.height - magnetometer.height - rotation.height - 3 * rightPane.spacing
+            onClicked: main.startRescan(sensor)
         }
     }
 
@@ -167,7 +181,6 @@ Item {
         onSensorChanged: if (sensor) sensor.recalibrate()
     }
 
-
     TopToolbar {
         id: topToolbar
 
diff --git a/tradeshow/iot-sensortag/sensortagdataprovider.cpp b/tradeshow/iot-sensortag/sensortagdataprovider.cpp
index 4ca749c..f5defa3 100644
--- a/tradeshow/iot-sensortag/sensortagdataprovider.cpp
+++ b/tradeshow/iot-sensortag/sensortagdataprovider.cpp
@@ -101,7 +101,7 @@ SensorTagDataProvider::SensorTagDataProvider(QString id, QObject* parent)
     altitude(0),
     m_tagType(AmbientTemperature | ObjectTemperature | Humidity | AirPressure | Light | Magnetometer | Rotation | Accelometer | Altitude),
     m_id(id),
-    m_state(Disconnected)
+    m_state(NotFound)
 {
 }
 
diff --git a/tradeshow/iot-sensortag/sensortagdataprovider.h b/tradeshow/iot-sensortag/sensortagdataprovider.h
index 3f55386..605c5d0 100644
--- a/tradeshow/iot-sensortag/sensortagdataprovider.h
+++ b/tradeshow/iot-sensortag/sensortagdataprovider.h
@@ -98,7 +98,7 @@ public:
                   Rotation = 1 << 6,
                   Accelometer = 1 << 7,
                   Altitude = 1 << 8};
-    enum ProviderState {Disconnected = 0, Scanning, Connected, Error};
+    enum ProviderState {NotFound = 0, Disconnected, Scanning, Connected, Error};
 
     explicit SensorTagDataProvider(QObject *parent = 0);
     SensorTagDataProvider(QString id, QObject *parent = 0);
diff --git a/tradeshow/iot-sensortag/sensortagdataproviderpool.cpp b/tradeshow/iot-sensortag/sensortagdataproviderpool.cpp
index f9edad0..987e8b3 100644
--- a/tradeshow/iot-sensortag/sensortagdataproviderpool.cpp
+++ b/tradeshow/iot-sensortag/sensortagdataproviderpool.cpp
@@ -74,16 +74,22 @@ SensorTagDataProviderPool::SensorTagDataProviderPool(QString poolName, QObject*
 
 void SensorTagDataProviderPool::startScanning()
 {
-    qDeleteAll(m_dataProviders);
-    m_dataProviders.clear();
-
-    m_discoveryAgent->start();
+    m_discoveryAgent->start(QBluetoothDeviceDiscoveryAgent::LowEnergyMethod);
 
     if (m_discoveryAgent->isActive()) {
-        m_deviceScanState = true;
+        emit scanStarted();
     }
 }
 
+void SensorTagDataProviderPool::disconnectProvider(QString id)
+{
+    SensorTagDataProvider *p = findProvider(id);
+    if (BluetoothDataProvider *btp = qobject_cast<BluetoothDataProvider*>(findProvider(id)))
+        btp->unbindDevice();
+    else if (p)
+        p->setState(SensorTagDataProvider::Disconnected);
+}
+
 void SensorTagDataProviderPool::setMacFilterList(const QStringList &addressList)
 {
     m_macFilters = addressList;
@@ -118,7 +124,6 @@ void SensorTagDataProviderPool::updateProviderForCloud()
 
 void SensorTagDataProviderPool::deviceDiscoveryFinished()
 {
-    m_deviceScanState = false;
     finishScanning();
     emit scanFinished();
 }
@@ -130,8 +135,6 @@ void SensorTagDataProviderPool::finishScanning()
 
 void SensorTagDataProviderPool::btDeviceFound(const QBluetoothDeviceInfo &info)
 {
-    qCDebug(boot2QtDemos) << "Found a Bluetooth device. Name:" << info.name() << ", addr:" << info.address().toString();
-
     if (info.coreConfigurations() & QBluetoothDeviceInfo::LowEnergyCoreConfiguration) {
         bool filtered = m_macFilters.length() || m_nameFilters.length();
         bool found = filtered ? false : true;
@@ -142,14 +145,24 @@ void SensorTagDataProviderPool::btDeviceFound(const QBluetoothDeviceInfo &info)
             found = true;
 
         if (found) {
-            qCDebug(boot2QtDemos) << "   Adding to the available devices";
-            BluetoothDataProvider* dataProvider = new BluetoothDataProvider(info.address().toString(), this);
-            BluetoothDevice *d = new BluetoothDevice(info);
-            dataProvider->bindToDevice(d);
-            m_dataProviders.append(dataProvider);
-            emit providerConnected(d->getAddress());
-            emit dataProvidersChanged();
-            connect(dataProvider, &SensorTagDataProvider::stateChanged, this, &SensorTagDataProviderPool::handleStateChange);
+            BluetoothDataProvider *dataProvider = static_cast<BluetoothDataProvider *>(findProvider(info.address().toString()));
+            if (!dataProvider) {
+                qCDebug(boot2QtDemos) << "Found a new Sensor tag. Name:" << info.name() << ", addr:" << info.address().toString() ;
+                dataProvider = new BluetoothDataProvider(info.address().toString(), this);
+                m_dataProviders.append(dataProvider);
+                emit dataProvidersChanged();
+            }
+            if (!dataProvider->device()) {
+                qCDebug(boot2QtDemos) << "Attach BluetoothDevice info for an existing Sensor Tag:" << info.name();
+                BluetoothDevice *d = new BluetoothDevice(info);
+                dataProvider->bindToDevice(d);
+                connect(dataProvider, &SensorTagDataProvider::stateChanged, this, &SensorTagDataProviderPool::handleStateChange);
+                dataProvider->startDataFetching();
+            }
+            else if (dataProvider->state() != SensorTagDataProvider::Connected) {
+                qCDebug(boot2QtDemos) << "Start service scan for already attached Sensor Tag" << dataProvider->id();
+                dataProvider->startServiceScan();
+            }
         }
     }
 }
@@ -184,6 +197,14 @@ void SensorTagDataProviderPool::deviceScanError(QBluetoothDeviceDiscoveryAgent::
     else
         qCDebug(boot2QtDemos) << "An unknown error has occurred.";
 
-    m_deviceScanState = false;
     emit scanFinished();
 }
+
+SensorTagDataProvider* SensorTagDataProviderPool::findProvider(QString id) const
+{
+    for (SensorTagDataProvider *p : m_dataProviders) {
+        if (id == p->id())
+            return p;
+    }
+    return 0;
+}
diff --git a/tradeshow/iot-sensortag/sensortagdataproviderpool.h b/tradeshow/iot-sensortag/sensortagdataproviderpool.h
index d7ac740..fe8b30f 100644
--- a/tradeshow/iot-sensortag/sensortagdataproviderpool.h
+++ b/tradeshow/iot-sensortag/sensortagdataproviderpool.h
@@ -66,6 +66,7 @@ public:
     explicit SensorTagDataProviderPool(QObject *parent = 0);
 
     void startScanning() override;
+    void disconnectProvider(QString id) override;
 
     // setMacFilterList takes presence over name filter
     Q_INVOKABLE void setMacFilterList(const QStringList& addressList);
@@ -77,9 +78,11 @@ public:
 protected:
     SensorTagDataProviderPool(QString poolName, QObject *parent = 0);
     virtual void finishScanning();
-
     void updateProviderForCloud();
 
+    QStringList m_macFilters;
+    QStringList m_nameFilters;
+
 private slots:
     void deviceDiscoveryFinished();
     void btDeviceFound(const QBluetoothDeviceInfo &info);
@@ -87,9 +90,8 @@ private slots:
     void deviceScanError(QBluetoothDeviceDiscoveryAgent::Error error);
 
 private:
-    QStringList m_macFilters;
-    QStringList m_nameFilters;
-    bool m_deviceScanState;
+    SensorTagDataProvider *findProvider(QString id) const;
+
     QBluetoothDeviceDiscoveryAgent *m_discoveryAgent;
     SensorTagDataProvider *m_providerForCloud;
 };