main.cpp Example File

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  #include <QtBluetooth/qlowenergyadvertisingdata.h>
  #include <QtBluetooth/qlowenergyadvertisingparameters.h>
  #include <QtBluetooth/qlowenergycharacteristic.h>
  #include <QtBluetooth/qlowenergycharacteristicdata.h>
  #include <QtBluetooth/qlowenergydescriptordata.h>
  #include <QtBluetooth/qlowenergycontroller.h>
  #include <QtBluetooth/qlowenergyservice.h>
  #include <QtBluetooth/qlowenergyservicedata.h>
  #include <QtCore/qbytearray.h>
  #include <QtCore/qcoreapplication.h>
  #include <QtCore/qlist.h>
  #include <QtCore/qscopedpointer.h>
  #include <QtCore/qtimer.h>

  int main(int argc, char *argv[])
  {
      QCoreApplication app(argc, argv);

      QLowEnergyAdvertisingData advertisingData;
      advertisingData.setDiscoverability(QLowEnergyAdvertisingData::DiscoverabilityGeneral);
      advertisingData.setIncludePowerLevel(true);
      advertisingData.setLocalName("HeartRateServer");
      advertisingData.setServices(QList<QBluetoothUuid>() << QBluetoothUuid::HeartRate);

      QLowEnergyCharacteristicData charData;
      charData.setUuid(QBluetoothUuid::HeartRateMeasurement);
      charData.setValue(QByteArray(2, 0));
      charData.setProperties(QLowEnergyCharacteristic::Notify);
      const QLowEnergyDescriptorData clientConfig(QBluetoothUuid::ClientCharacteristicConfiguration,
                                                  QByteArray(2, 0));
      charData.addDescriptor(clientConfig);

      QLowEnergyServiceData serviceData;
      serviceData.setType(QLowEnergyServiceData::ServiceTypePrimary);
      serviceData.setUuid(QBluetoothUuid::HeartRate);
      serviceData.addCharacteristic(charData);

      const QScopedPointer<QLowEnergyController> leController(QLowEnergyController::createPeripheral());
      const QScopedPointer<QLowEnergyService> service(leController->addService(serviceData));
      leController->startAdvertising(QLowEnergyAdvertisingParameters(), advertisingData,
                                     advertisingData);

      QTimer heartbeatTimer;
      quint8 currentHeartRate = 60;
      enum ValueChange { ValueUp, ValueDown } valueChange = ValueUp;
      const auto heartbeatProvider = [&service, &currentHeartRate, &valueChange]() {
          QByteArray value;
          value.append(char(0)); // Flags that specify the format of the value.
          value.append(char(currentHeartRate)); // Actual value.
          QLowEnergyCharacteristic characteristic
                  = service->characteristic(QBluetoothUuid::HeartRateMeasurement);
          Q_ASSERT(characteristic.isValid());
          service->writeCharacteristic(characteristic, value); // Potentially causes notification.
          if (currentHeartRate == 60)
              valueChange = ValueUp;
          else if (currentHeartRate == 100)
              valueChange = ValueDown;
          if (valueChange == ValueUp)
              ++currentHeartRate;
          else
              --currentHeartRate;
      };
      QObject::connect(&heartbeatTimer, &QTimer::timeout, heartbeatProvider);
      heartbeatTimer.start(1000);

      auto reconnect = [&leController, advertisingData]() {
          leController->startAdvertising(QLowEnergyAdvertisingParameters(), advertisingData,
                                         advertisingData);
      };
      QObject::connect(leController.data(), &QLowEnergyController::disconnected, reconnect);

      return app.exec();
  }