蓝牙断开连接

Question

我有一个与BLE设备通信的应用程序。它运作良好，但一段时间后我得到错误：

qt.bluetooth.bluez: void QBluetoothSocketPrivate::_q_readNotify() 22
error: -1 "Function not implemented" 
Controller 
Error: 1 Remote device disconnected

我的设备已断开连接。 从设备接收值时会发生此错误

我找不到问题。我在Ubuntu 16.04（Qt 5.4）下的两台计算机上运行应用程序。该问题仅发生在第二台计算机上。我比较了两台计算机的包装，但没有发现任何差异。

我的bluez版本是：5.37-0ubuntu5

#include "myapp.h"
#include <QCoreApplication>

MyApp::MyApp()
    : m_deviceDiscoveryAgent(0)
    , m_controller(0)
    , m_service(0)
    , num(0)
{
    m_deviceDiscoveryAgent = new QBluetoothDeviceDiscoveryAgent(this);

    connect(m_deviceDiscoveryAgent, SIGNAL(deviceDiscovered(const QBluetoothDeviceInfo&)),
            this, SLOT(addDevice(const QBluetoothDeviceInfo&)));
    connect(m_deviceDiscoveryAgent, SIGNAL(error(QBluetoothDeviceDiscoveryAgent::Error)),
            this, SLOT(deviceScanError(QBluetoothDeviceDiscoveryAgent::Error)));
    connect(m_deviceDiscoveryAgent, SIGNAL(finished()), this, SLOT(scanFinished()));
    connect(m_deviceDiscoveryAgent, SIGNAL(canceled()), this, SLOT(scanCancel()));

    qDebug()<<("Scanning for devices...");
    m_deviceDiscoveryAgent->start();
}

MyApp::~MyApp()
{
    delete m_deviceDiscoveryAgent;
    delete m_controller;
    delete m_service;
}

void MyApp::addDevice(const QBluetoothDeviceInfo &device)
{
    if (device.coreConfigurations() & QBluetoothDeviceInfo::LowEnergyCoreConfiguration) {
        qDebug()<<device.address().toString();
    }
}

void MyApp::scanServices(const QString &address)
{
    qDebug()<<"scan service"<<address;

    QBluetoothDeviceInfo device;
    for(int i=0; i<m_deviceDiscoveryAgent->discoveredDevices().length(); i++) {
        if(m_deviceDiscoveryAgent->discoveredDevices().at(i).address().toString()
                == address) {
            qDebug()<<"I find my service";
            device = m_deviceDiscoveryAgent->discoveredDevices().at(i);
        }
    }

    if (m_controller) {
        qDebug()<<m_controller<<m_controller->remoteAddress() <<device.address();
        if(m_controller->remoteAddress() != device.address()) {
            m_controller->disconnectFromDevice();
            delete m_controller;
            m_controller = 0;
        }
    }
    if (!m_controller) {
        // Connecting signals and slots for connec    DeviceInfo m_currentDevice;
        m_controller = new QLowEnergyController(device.address());
        connect(m_controller, SIGNAL(connected()),
                this, SLOT(deviceConnected()));
        connect(m_controller, SIGNAL(error(QLowEnergyController::Error)),
                this, SLOT(controllerError(QLowEnergyController::Error)));
        connect(m_controller, SIGNAL(disconnected()),
                this, SLOT(deviceDisconnected()));
        connect(m_controller, SIGNAL(serviceDiscovered(QBluetoothUuid)),
                this, SLOT(serviceDiscovered(QBluetoothUuid)));
        connect(m_controller, SIGNAL(discoveryFinished()),
                this, SLOT(serviceScanDone()));
    }
    m_controller->connectToDevice();
}

void MyApp::scanFinished()
{
    qDebug()<<"scanFinished()";

     scanServices("xx:xx:xx:xx:xx:xx");
}

void MyApp::scanCancel()
{
    qDebug()<<"scan cancel";
}

void MyApp::deviceScanError(QBluetoothDeviceDiscoveryAgent::Error error)
{
    if (error == QBluetoothDeviceDiscoveryAgent::PoweredOffError)
        qDebug()<<("The Bluetooth adaptor is powered off, power it on before doing discovery.");
    else if (error == QBluetoothDeviceDiscoveryAgent::InputOutputError)
        qDebug()<<("Writing or reading from the device resulted in an error.");
    else
        qDebug()<<("An unknown error has occurred.");
}

void MyApp::serviceDiscovered(const QBluetoothUuid &gatt)
{
    qDebug()<<"serviceDiscovered"<<gatt<<UUID_AUDIO_SERVICE;
    if (gatt.toString().contains(UUID_AUDIO_SERVICE) ){
        qDebug()<<("Audio service discovered. Waiting for service scan to be done...");
        m_service = m_controller->createServiceObject(gatt);
    }
}

void MyApp::serviceScanDone()
{
    qDebug()<<"service scan done";

    if (!m_service) {
        qDebug()<<("Service not found.");
        return;
    }

    connect(m_service, SIGNAL(stateChanged(QLowEnergyService::ServiceState)),
            this, SLOT(serviceDetailsDiscovered(QLowEnergyService::ServiceState)));
    connect(m_service, SIGNAL(characteristicChanged(QLowEnergyCharacteristic,QByteArray)),
            this, SLOT(updateAudioValue(QLowEnergyCharacteristic,QByteArray)));
    connect(m_service, SIGNAL(descriptorWritten(QLowEnergyDescriptor,QByteArray)),
            this, SLOT(confirmedDescriptorWrite(QLowEnergyDescriptor,QByteArray)));

    qDebug()<<"start discover details";
    m_service->discoverDetails();

}

void MyApp::controllerError(QLowEnergyController::Error error)
{
    qDebug()<<("Cannot connect to remote device.");
    qWarning() << "Controller Error:" << error;
}

void MyApp::deviceConnected()
{
    qDebug()<<"deviceConnected, request discoverServices";
    m_controller->discoverServices();
}

void MyApp::deviceDisconnected()
{
    qWarning() << "Remote device disconnected";
}

void MyApp::serviceDetailsDiscovered(QLowEnergyService::ServiceState s)
{
    qDebug()<<"service state changed"<<s;
    if (s != QLowEnergyService::ServiceDiscovered) {
        return;
    }

    QLowEnergyService *service = qobject_cast<QLowEnergyService *>(sender());
    if (!service) {
        qDebug()<<"service not found";
        return;
    }
    qDebug()<<"service found"<<service->serviceUuid()<<m_service->serviceUuid();

    const QList<QLowEnergyCharacteristic> chars = service->characteristics();
    foreach (const QLowEnergyCharacteristic &ch, chars) {
        if(ch.uuid().toString() == UUID_CHARACT_1) {
            foreach (const QLowEnergyDescriptor &d, ch.descriptors()) {
                qDebug()<<"\tdescriptor"<<d.name()<<d.uuid();
                if(d.uuid().toString() == UUID_DESC_1) {
                    qDebug()<<"j'écris sur mon descriptor";
                    service->writeDescriptor(d, QByteArray::fromHex("0100"));
                }
            }
        }
        if(ch.uuid().toString() == UUID_CHARACT_2) {
            foreach (const QLowEnergyDescriptor &d, ch.descriptors()) {
                qDebug()<<"\tdescriptor"<<d.name()<<d.uuid();
                if(d.uuid().toString() == UUID_DESC_2) {
                    qDebug()<<"j'écris sur mon descriptor";
                    service->writeDescriptor(d, QByteArray::fromHex("0100"));
                }
            }
        }
    }
}

void MyApp::updateAudioValue(const QLowEnergyCharacteristic &c, const QByteArray &value)
{
    qDebug()<<"updateAudioValue"<<c.uuid()<<value<<"->"<<num;
}

void MyApp::confirmedDescriptorWrite(const QLowEnergyDescriptor &d, const QByteArray &value)
{
    qDebug()<<"confirmedDescriptorWrite();";
}

void MyApp::serviceError(QLowEnergyService::ServiceError e)
{
    switch (e) {
    case QLowEnergyService::DescriptorWriteError:
        qDebug()<<("Cannot obtain HR notifications");
        break;
    default:
        qWarning() << "HR service error:" << e;
    }
}

void MyApp::connectDevice(const QBluetoothDeviceInfo& device)
{
    qDebug()<<"connectDevice";

    if (m_controller!=NULL) {
        m_controller->disconnectFromDevice();
        delete m_controller;
        m_controller = 0;
    }

    m_controller = new QLowEnergyController(device.address(),
                                            this);
    connect(m_controller, SIGNAL(error(QLowEnergyController::Error)),
            this, SLOT(controllerError(QLowEnergyController::Error)));
    connect(m_controller, SIGNAL(connected()),
            this, SLOT(deviceConnected()));
    connect(m_controller, SIGNAL(disconnected()),
            this, SLOT(deviceDisconnected()));
    connect(m_controller, SIGNAL(serviceDiscovered(QBluetoothUuid)),
            this, SLOT(serviceDiscovered(QBluetoothUuid)));
    connect(m_controller, SIGNAL(discoveryFinished()),
            this, SLOT(serviceScanDone()));
    m_controller->connectToDevice();
}