QBluetoothDeviceDiscoveryAgent#
The QBluetoothDeviceDiscoveryAgent
class discovers the Bluetooth devices nearby. More…
Synopsis#
Functions#
def
discoveredDevices
()def
error
()def
errorString
()def
isActive
()def
lowEnergyDiscoveryTimeout
()def
setLowEnergyDiscoveryTimeout
(msTimeout)
Slots#
Signals#
def
canceled
()def
deviceDiscovered
(info)def
deviceUpdated
(info, updatedFields)def
errorOccurred
(error)def
finished
()
Static functions#
def
supportedDiscoveryMethods
()
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description#
Warning
This section contains snippets that were automatically translated from C++ to Python and may contain errors.
To discover the nearby Bluetooth devices:
create an instance of
QBluetoothDeviceDiscoveryAgent
,connect to either the
deviceDiscovered()
orfinished()
signals,and call
start()
.def startDeviceDiscovery(self): # Create a discovery agent and connect to its signals discoveryAgent = QBluetoothDeviceDiscoveryAgent(self) connect(discoveryAgent, SIGNAL(deviceDiscovered(QBluetoothDeviceInfo)), self, SLOT(deviceDiscovered(QBluetoothDeviceInfo))) # Start a discovery discoveryAgent.start() #... # In your local slot, read information about the found devices def deviceDiscovered(self, device): print("Found device():", device.name(), '(', device.address().toString(), ')')
To retrieve results asynchronously, connect to the deviceDiscovered()
signal. To get a list of all discovered devices, call discoveredDevices()
after the finished()
signal.
This class can be used to discover Classic and Low Energy Bluetooth devices. The individual device type can be determined via the coreConfigurations()
attribute. In most cases the list returned by discoveredDevices()
contains both types of devices. However not every platform can detect both types of devices. On platforms with this limitation (for example iOS only suports Low Energy discovery), the discovery process will limit the search to the type which is supported.
Note
Since Android 6.0 the ability to detect devices requires ACCESS_COARSE_LOCATION.
Note
The Win32 backend currently does not support the Received Signal Strength Indicator (RSSI), as well as the Manufacturer Specific Data, or other data updates advertised by Bluetooth LE devices after discovery.
- class PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent([parent=None])#
PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent(deviceAdapter[, parent=None])
- Parameters:
deviceAdapter –
PySide6.QtBluetooth.QBluetoothAddress
parent –
PySide6.QtCore.QObject
Constructs a new Bluetooth device discovery agent with parent parent
.
Constructs a new Bluetooth device discovery agent with parent
.
It uses deviceAdapter
for the device search. If deviceAdapter
is default constructed the resulting QBluetoothDeviceDiscoveryAgent
object will use the local default Bluetooth adapter.
If a deviceAdapter
is specified that is not a local adapter error()
will be set to InvalidBluetoothAdapterError
. Therefore it is recommended to test the error flag immediately after using this constructor.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.Error#
Indicates all possible error conditions found during Bluetooth device discovery.
Constant
Description
QBluetoothDeviceDiscoveryAgent.NoError
No error has occurred.
QBluetoothDeviceDiscoveryAgent.PoweredOffError
The Bluetooth adaptor is powered off, power it on before doing discovery.
QBluetoothDeviceDiscoveryAgent.InputOutputError
Writing or reading from the device resulted in an error.
QBluetoothDeviceDiscoveryAgent.InvalidBluetoothAdapterError
The passed local adapter address does not match the physical adapter address of any local Bluetooth device.
QBluetoothDeviceDiscoveryAgent.UnsupportedPlatformError
Device discovery is not possible or implemented on the current platform. The error is set in response to a call to
start()
. An example for such cases are iOS versions below 5.0 which do not support Bluetooth device search at all.QBluetoothDeviceDiscoveryAgent.UnsupportedDiscoveryMethod
One of the requested discovery methods is not supported by the current platform.
QBluetoothDeviceDiscoveryAgent.LocationServiceTurnedOffError
The location service is turned off. Usage of Bluetooth APIs is not possible when location service is turned off.
QBluetoothDeviceDiscoveryAgent.MissingPermissionsError
The operating system requests permissions which were not granted by the user.
QBluetoothDeviceDiscoveryAgent.UnknownError
An unknown error has occurred.
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.DiscoveryMethod#
(inherits enum.Flag
) This enum descibes the type of discovery method employed by the QBluetoothDeviceDiscoveryAgent
.
Constant
Description
QBluetoothDeviceDiscoveryAgent.NoMethod
The discovery is not possible. None of the available methods are supported.
QBluetoothDeviceDiscoveryAgent.ClassicMethod
The discovery process searches for Bluetooth Classic (BaseRate) devices.
QBluetoothDeviceDiscoveryAgent.LowEnergyMethod
The discovery process searches for Bluetooth Low Energy devices.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.canceled()#
This signal is emitted when device discovery is aborted by a call to stop()
.
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.deviceDiscovered(info)#
- Parameters:
This signal is emitted when the Bluetooth device described by info
is discovered.
The signal is emitted as soon as the most important device information has been collected. However, as long as the finished()
signal has not been emitted the information collection continues even for already discovered devices. This is particularly true for signal strength information (RSSI) and manufacturer data updates. If the use case requires continuous manufacturer data or RSSI updates it is advisable to retrieve the device information via discoveredDevices()
once the discovery has finished or listen to the deviceUpdated()
signal.
If lowEnergyDiscoveryTimeout()
is larger than 0 the signal is only ever emitted when at least one attribute of info
changes. This reflects the desire to receive updates as more precise information becomes available. The exception to this behavior is the case when lowEnergyDiscoveryTimeout
is set to 0
. A timeout of 0
expresses the desire to monitor the appearance and disappearance of Low Energy devices over time. Under this condition the deviceDiscovered() signal is emitted even if info
has not changed since the last signal emission.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.deviceUpdated(info, updatedFields)#
- Parameters:
updatedFields – Combination of
QBluetoothDeviceInfo.Field
This signal is emitted when the agent receives additional information about the Bluetooth device described by info
. The updatedFields
flags tell which information has been updated.
During discovery, some information can change dynamically, such as signal strength
and manufacturerData
. This signal informs you that if your application is displaying this data, it can be updated, rather than waiting until the discovery has finished.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.discoveredDevices()#
- Return type:
.list of QBluetoothDeviceInfo
Returns a list of all discovered Bluetooth devices.
Returns the last error.
Any possible previous errors are cleared upon restarting the discovery.
This signal is emitted when an error
occurs during Bluetooth device discovery. The error
parameter describes the error that occurred.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.errorString()#
- Return type:
str
Returns a human-readable description of the last error.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.finished()#
This signal is emitted when Bluetooth device discovery completes. The signal is not going to be emitted if the device discovery finishes with an error.
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.isActive()#
- Return type:
bool
Returns true if the agent is currently discovering Bluetooth devices, otherwise returns false.
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.lowEnergyDiscoveryTimeout()#
- Return type:
int
Returns a timeout in milliseconds that is applied to the Bluetooth Low Energy device search. A value of -1
implies that the platform does not support this property and the timeout for the device search cannot be adjusted. A return value of 0
implies a never-ending search which must be manually stopped via stop()
.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.setLowEnergyDiscoveryTimeout(msTimeout)#
- Parameters:
msTimeout – int
Sets the maximum search time for Bluetooth Low Energy device search to timeout
in milliseconds. If timeout
is 0
the discovery runs until stop()
is called.
This reflects the fact that the discovery process for Bluetooth Low Energy devices is mostly open ended. The platform continues to look for more devices until the search is manually stopped. The timeout ensures that the search is aborted after timeout
milliseconds. Of course, it is still possible to manually abort the discovery by calling stop()
.
The new timeout value does not take effect until the device search is restarted. In addition the timeout does not affect the classic Bluetooth device search. Depending on the platform the classic search may add more time to the total discovery process beyond timeout
.
For a reliable Bluetooth Low Energy discovery, use at least 40000 milliseconds.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.start()#
Starts Bluetooth device discovery, if it is not already started.
The deviceDiscovered()
signal is emitted as each device is discovered. The finished()
signal is emitted once device discovery is complete. The discovery utilizes the maximum set of supported discovery methods on the platform.
See also
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.start(method)
- Parameters:
method – Combination of
QBluetoothDeviceDiscoveryAgent.DiscoveryMethod
Starts Bluetooth device discovery, if it is not already started and the provided methods
are supported. The discovery methods
limit the scope of the device search. For example, if the target service or device is a Bluetooth Low Energy device, this function could be used to limit the search to Bluetooth Low Energy devices and thereby reduces the discovery time significantly.
Note
methods
only determines the type of discovery and does not imply the filtering of the results. For example, the search may still contain classic bluetooth devices despite methods
being set to LowEnergyMethod
only. This may happen due to previously cached search results which may be incorporated into the search results.
- PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.stop()#
Stops Bluetooth device discovery. The cancel() signal is emitted once the device discovery is canceled. start()
maybe called before the cancel signal is received. Once start()
has been called the cancel signal from the prior discovery will be discarded.
- static PySide6.QtBluetooth.QBluetoothDeviceDiscoveryAgent.supportedDiscoveryMethods()#
- Return type:
Combination of
QBluetoothDeviceDiscoveryAgent.DiscoveryMethod
This function returns the discovery methods supported by the current platform. It can be used to limit the scope of the device discovery.