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btscanner example does not work, cannot find BLE host device

  • Hi,

    I am a newbie working on BLE examples; however none of the BLE examples work on both of my desktop with CyPress BLE dongle and my laptop.

    Could anyone help me and tell what is happening?

    I did a little modification on the btscanner example, and here is my own codes:

    QString localDeviceName;
    QBluetoothAddress dongleAddress;
    QBluetoothHostInfo dongleHostInfo;

    // Check if Bluetooth is available on this device
    QList<QBluetoothHostInfo> dongleHostInfoList = QBluetoothLocalDevice::allDevices();
    if (dongleHostInfoList.count() > 1){
        QStringList dongleNameStringList;
        for (int n=0; n<dongleHostInfoList.count(); n++){
            dongleNameStringList <<;
        QString dongleNameString = QInputDialog::getItem(0, QString("Sen Dongle Select"), QString("Please select your BLE Dongle."), dongleNameStringList, 0, false);
        dongleAddress =;
    } else if(dongleHostInfoList.count() == 1){
        dongleAddress =;
    }else   {
        qDebug() << QString ("No Device Detected");
    localDevice = new QBluetoothLocalDevice(dongleAddress);

    Unfortunately, I never find my BLE host device.

    Please help me.

    Thank you!

  • Hi Sen,
    What is the OS you are running your code? Does the BT device work (in Linux commands like $hcitool dev; $hcitool scan).

  • Me too. I use the linux command line tools to scan and than Qt to manage the ble.

  • @yeckel said:

    oes the BT device work

    I just figured it out that Qt does not support windows.
    I am going to install Linux as a second OS.

    Do you have any suggestion?

    Thank you!

  • Yep It's not supported on Windows. Easiest is to use Ubuntu. You should be able to install it in for example VirtualBox and share the USB device there.