How to enumerate Bluetooth devices using Qt

Question

I want to search bluetooth devices available and list them but the code I am following from documenation doesn't work.

BluetoothDevices::BluetoothDevices(QObject *parent) : QObject(parent)
{

}

// search Bluetooth devices
void BluetoothDevices::startDeviceDiscovery()
{
    qDebug() << "Bluetooth discovery started";

    // Create a discovery agent and connect to its signals
    //QBluetoothDeviceDiscoveryAgent *discoveryAgent = new QBluetoothDeviceDiscoveryAgent(this);
    discoveryAgent = new QBluetoothDeviceDiscoveryAgent(this);
    connect(discoveryAgent, SIGNAL(deviceDiscovered(QBluetoothDeviceInfo)),
            this, SLOT(deviceDiscovered(QBluetoothDeviceInfo)));

    // Start a discovery
    discoveryAgent->start();
}

void BluetoothDevices::deviceDiscovered(const QBluetoothDeviceInfo &device)
{
     qDebug() << "Found new device:" << device.name() << '(' << device.address().toString() << ')';
}

In main window I start the search:

void MainWindow::on_pushButtonSearchBluetooth_clicked()
{
    bluetoothDevices.startDeviceDiscovery();
}

I expect the deviceDiscovered() slot to get called with the device names as it gets found but this slot never gets called. I never hear anything back after initiating discovery. When I do search bluetooth devices manually from control panel, it does find couple of laptops. What else do I need to do to find them through my app?

I am using windows 7 and Qt 5.5.

Answer 1

I have the same problem. You can connect signal connect(m_discoveryAgent, SIGNAL(error(QBluetoothServiceDiscoveryAgent::Error)), this, SLOT(error(QBluetoothServiceDiscoveryAgent::Error))); and you can see that slot emitted with error InvalidBluetoothAdapterError. I try it on WIN7 and WIN10 and it not worked. In Ubuntu the same code work properly.

Answer 2

It seems that bluetooth not supported in windows platforms.

Currently, the API is supported on the following platforms: Android, iOS, Linux (BlueZ 4.x/5.x) and OS X. from http://doc.qt.io/qt-5/qtbluetooth-index.html