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Bluetooth RFCOMM Connection Problems with socket
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Hello guys. I have to communicate with device via Bluetooth Classic. I can connect to device and send command. If I switch GUI Page, the connection does not lost but socket->state() show me that is unconnected state. What is not correct here? beepBuzzor is in the socketConnected() SLOT and it works after connectToService call. But if I clos my scanningpage in qml and click on the button startMotor from other qml page, the state is unconnected but why? If I put the startMotor button in scanningPage where I have selected the right device, it works. but not on other pages.
BluetoothManager::BluetoothManager(QObject *parent) : QObject(parent) { socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol); } void BluetoothManager::startDiscovery() { // Check if Bluetooth is available on this device if (localDevice.isValid()) { qDebug() << "Bluetooth is available on this device"; //Turn BT on localDevice.powerOn(); // Make it visible to others localDevice.setHostMode(QBluetoothLocalDevice::HostDiscoverable); //Read local device name & address qDebug() << "Local Device:" << localDevice.name() << "(" << "Address:" << localDevice.address() << ")"; // Create a discovery agent and connect to its signals discoveryAgent = new QBluetoothDeviceDiscoveryAgent(this); connect(discoveryAgent, SIGNAL(finished()), this, SLOT(deviceDiscoverFinished())); // Start a discovery // Trick: da es kein DiscoveryTimer für Classic gibt, suchen wir nach LE devices, da BT121 BLE unterstützt. // Die Verbindung erfolgt jedoch über RFCOMM sobald man sich mit dem Gerät verbindet. discoveryAgent->setLowEnergyDiscoveryTimeout(5000); discoveryAgent->start(QBluetoothDeviceDiscoveryAgent::LowEnergyMethod); qDebug() << "Device discover started"; } else { qDebug() << "Bluetooth is not available on this device"; } } //SLOT for the finish of device Discovery void BluetoothManager::deviceDiscoverFinished() { qDebug() << "Device discover finished"; listOfDevices = discoveryAgent->discoveredDevices(); qDebug() << "Found new devices:"; for (int i = 0; i < listOfDevices.size(); i++) { //Q_OS_IOS / MAC do not need here cuz the run is on android device, delete later //We do not find galileo device on MacBook #if defined (Q_OS_IOS) || defined (Q_OS_MAC) // On MacOS and iOS we get no access to device address, // only unique UUIDs generated by Core Bluetooth. qDebug() << "getting address from deviceUuid()" << listOfDevices.at(i).name().trimmed() << " ( " << listOfDevices.at(i).deviceUuid().toString().trimmed() << " ) "; setDevice(listOfDevices.at(i).name().trimmed() + " (" + listOfDevices.at(i).deviceUuid().toString().trimmed() + ")"); #else qDebug() << listOfDevices.at(i).name().trimmed() << " (" << listOfDevices.at(i).address().toString().trimmed() << ")"; setDevice(listOfDevices.at(i).name().trimmed() + " (" + listOfDevices.at(i).address().toString().trimmed() + ")"); #endif } } /** * In GUI (QML) user select a device with index i. * Create a new socket, using Rfcomm protocol to communicate */ void BluetoothManager::deviceSelected(int i) { selectedDevice = listOfDevices.at(i); #if defined (Q_OS_IOS) || defined (Q_OS_MAC) qDebug() << "User select a device: " << selectedDevice.name() << " (" << selectedDevice.deviceUuid().toString().trimmed() << ")"; #else qDebug() << "User select a device: " << selectedDevice.name() << " (" << selectedDevice.address().toString().trimmed() << ")"; #endif if (localDevice.pairingStatus(selectedDevice.address())== QBluetoothLocalDevice::Paired) { qDebug() << "Pairing is allready done"; } else { qDebug() << "Not paired. Please do pairing first for communication with device!"; } selecDevAdress = selectedDevice.address(); connectToSvc(); //Connect SIGNALS with SLOTS connect(socket, SIGNAL(error(QBluetoothSocket::SocketError)), this, SLOT(socketError(QBluetoothSocket::SocketError))); connect(socket, SIGNAL(connected()), this, SLOT(socketConnected())); connect(socket, SIGNAL(disconnected()), this, SLOT(socketDisconnected())); connect(socket, SIGNAL(readyRead()), this, SLOT(socketRead())); connect(socket, SIGNAL(stateChanged(QBluetoothSocket::SocketState)), this, SLOT(socketStateChanged())); } void BluetoothManager::connectToSvc() { qDebug() << "Create socket"; //socket->connectToService(selecDevAdress, QBluetoothUuid(QString("00001101-0000-1000-8000-00805F9B34FB")), QIODevice::ReadWrite); //static const QString serviceUuid(QStringLiteral("00001101-0000-1000-8000-00805F9B34FB")); socket->connectToService(selectedDevice.address(), QBluetoothUuid(QString("00001101-0000-1000-8000-00805F9B34FB")), QIODevice::ReadWrite); //Also works with this line instead of the two above (with declaration of serviceUuid) //socket->connectToService(QBluetoothAddress(selectedDevice.address()),QBluetoothUuid(QBluetoothUuid::SerialPort)); socket->open(QIODevice::ReadWrite); } //SLOT wenn Socket verbunden ist void BluetoothManager::socketConnected() { //qDebug() << ("Connected to: "+socket->peerAddress().toString() +":"+socket->peerPort()); qDebug() << ("Connected to: "+socket->peerAddress().toString()); qDebug() << "Socket connected"; qDebug() << "Local: " << socket->localName() << socket->localAddress().toString() << socket->localPort(); qDebug() << "Peer: " << socket->peerName() << socket->peerAddress().toString() << socket->peerPort(); //Do "beep" sound commando after succesfull connection to Galileo device beepBuzzor(); } /** * Socket disconnected. * Delete socket, free the memory. */ //SLOT für Verbindungsabbruch von Socket void BluetoothManager::socketDisconnected() { qDebug() << "Socket disconnected"; socket->deleteLater(); } void BluetoothManager::socketError(QBluetoothSocket::SocketError error) { qDebug() << "Socket error: " << error; } void BluetoothManager::socketStateChanged() { int socketState = socket->state(); if(socketState == QAbstractSocket::UnconnectedState) { qDebug() << "unconnected"; } else if(socketState == QAbstractSocket::HostLookupState) { qDebug() << "host lookup"; } else if(socketState == QAbstractSocket::ConnectingState ) { qDebug() << "connecting"; } else if(socketState == QAbstractSocket::ConnectedState) { qDebug() << "connected"; } else if(socketState == QAbstractSocket::BoundState) { qDebug() << "bound"; } else if(socketState == QAbstractSocket::ClosingState) { qDebug() << "closing"; } else if(socketState == QAbstractSocket::ListeningState) { qDebug() << "listening"; } } // SLOT when data ready on bluetooth socket void BluetoothManager::socketRead() { qDebug() << "socketRead()"; QByteArray recievedData = socket->readAll(); emit dataRecieved(recievedData); } /** * Get a string with device info */ const QString &BluetoothManager::device() const { return deviceInfo; } void BluetoothManager::setDevice(const QString &newDevice) { if (newDevice != deviceInfo) { deviceInfo = newDevice; emit deviceChanged(); } } void BluetoothManager::beepBuzzor() { QByteArray beep; beep.append(QByteArray::fromRawData("\x04\x00\x09\xD0\x07\x32\x00", 7)); command(beep); } void BluetoothManager::startMotor() //this slot I call from qml but nothing happens cuz state unconnected but the connection is established to device! Whats not correct? { qDebug() << "startMotor slot"; if(socket->state() == QBluetoothSocket::UnconnectedState){ qDebug() << "Socket Unconnected"; } else{ qDebug() << "Socket Unonnected"; } socketStateChanged(); //command(start); }void BluetoothManager::command(QByteArray &cmdBuf)
{
socket->write(cmdBuf);
}