QSensor¶

The QSensor class represents a single hardware sensor. More…

Inherited by: QAccelerometer, QAltimeter, QAmbientLightSensor, QAmbientTemperatureSensor, QCompass, QDistanceSensor, QGyroscope, QHolsterSensor, QHumiditySensor, QIRProximitySensor, QLidSensor, QLightSensor, QMagnetometer, QOrientationSensor, QPressureSensor, QProximitySensor, QRotationSensor, QTapSensor, QTiltSensor

Synopsis¶

Functions¶

def addFilter (filter)
def availableDataRates ()
def axesOrientationMode ()
def backend ()
def bufferSize ()
def connectToBackend ()
def currentOrientation ()
def dataRate ()
def description ()
def efficientBufferSize ()
def error ()
def filters ()
def identifier ()
def isActive ()
def isAlwaysOn ()
def isBusy ()
def isConnectedToBackend ()
def isFeatureSupported (feature)
def maxBufferSize ()
def outputRange ()
def outputRanges ()
def reading ()
def removeFilter (filter)
def setActive (active)
def setAlwaysOn (alwaysOn)
def setAxesOrientationMode (axesOrientationMode)
def setBufferSize (bufferSize)
def setCurrentOrientation (currentOrientation)
def setDataRate (rate)
def setEfficientBufferSize (efficientBufferSize)
def setIdentifier (identifier)
def setMaxBufferSize (maxBufferSize)
def setOutputRange (index)
def setSkipDuplicates (skipDuplicates)
def setUserOrientation (userOrientation)
def skipDuplicates ()
def type ()
def userOrientation ()

Slots¶

def start ()
def stop ()

Signals¶

def activeChanged ()
def alwaysOnChanged ()
def availableSensorsChanged ()
def axesOrientationModeChanged (axesOrientationMode)
def bufferSizeChanged (bufferSize)
def busyChanged ()
def currentOrientationChanged (currentOrientation)
def dataRateChanged ()
def efficientBufferSizeChanged (efficientBufferSize)
def maxBufferSizeChanged (maxBufferSize)
def readingChanged ()
def sensorError (error)
def skipDuplicatesChanged (skipDuplicates)
def userOrientationChanged (userOrientation)

Static functions¶

def defaultSensorForType (type)
def sensorTypes ()
def sensorsForType (type)

Detailed Description¶

The life cycle of a sensor is typically:

Create a sub-class of QSensor on the stack or heap.

Setup as required by the application.

Start receiving values.

Sensor data is used by the application.

Stop receiving values.

The sensor data is delivered via QSensorReading and its sub-classes.

Orientation¶

Some sensors react to screen orientation changes, such as QAccelerometer , QMagnetometer and QRotationSensor . These are so called orientable sensors. For orientable sensors, QSensor supports changing the reporting of the reading values based on the orientation of the screen.

For orientable sensors, the axesOrientationMode property controls how the orientation affects the reading values.

In the default mode, FixedOrientation , the reading values remain unaffected by the orientation. In the AutomaticOrientation mode, the reading values are automatically rotated by taking the current screen orientation into account. And finally, in the UserOrientation mode, the reading values are rotated according to a user-specified orientation.

The functionality of this is only available if it is supported by the backend and if the sensor is orientable, which can be checked by calling isFeatureSupported() with the AxesOrientation flag.

The orientation values here are always of the screen orientation, not the device orientation. The screen orientation is the orientation of the GUI. For example when rotating a device by 90 degrees counter-clockwise, the screen orientation compensates for that by rotating 90 degrees clockwise, to the effect that the GUI is still facing upright after the device has been rotated. Note that applications can lock the screen orientation, for example to force portrait or landscape mode. For locked orientations, orientable sensors will not react with reading changes if the device orientation is changed, as orientable sensors react to screen orientation changes only. This makes sense, as the purpose of orientable sensors is to keep the sensor orientation in sync with the screen orientation.

The orientation values range from 0 to 270 degrees. The orientation is applied in clockwise direction, e.g. an orientation value of 90 degrees means that the screen has been rotated 90 degress to the right from its origin position, to compensate a device rotation of 90 degrees to the left.

See also

QSensorReading

class QSensor(type[, parent=Q_NULLPTR])¶

param type

QByteArray

param parent

QObject

Construct the type sensor as a child of parent .

Do not use this constructor if a derived class exists for the specific sensor type.

The wrong way is to use the base class constructor:

QSensor *magnetometer = new QSensor(QMagnetometer::type, this);

The right way is to create an instance of the derived class:

QMagnetometer *magnetometer = new QMagnetometer(this);

The derived classes have additional properties and data members which are needed for certain features such as geo value support in QMagnetometer or acceleration mode support in QAccelerometer . These features will only work properly when creating a sensor instance from a QSensor subclass.

Only use this constructor if there is no derived sensor class available. Note that all built-in sensors have a derived class, so using this constructor should only be necessary when implementing custom sensors, like in the Grue sensor example .

PySide2.QtSensors.QSensor.Feature¶

Lists optional features a backend might support.

The features common to all sensor types are:

Constant	Description
QSensor.Buffering	The backend supports buffering of readings, controlled by the `bufferSize` property.
QSensor.AlwaysOn	The backend supports changing the policy on whether to suspend when idle, controlled by the `alwaysOn` property.
QSensor.SkipDuplicates	The backend supports skipping of same or very similar successive readings. This can be enabled by setting the `skipDuplicates` property to true.

The features of QMagnetometer are:

Constant	Description
QSensor.GeoValues	The backend supports returning geo values, which can be controlled with the `returnGeoValues` property.

The features of QLightSensor are:

Constant	Description
QSensor.FieldOfView	The backend specifies its field of view, which can be read from the `fieldOfView` property.

The features of QAccelerometer are:

Constant	Description
QSensor.AccelerationMode	The backend supports switching the acceleration mode of the acceleromter with the `accelerationMode` property.

The features of QPressureSensor are:

Constant	Description
QSensor.PressureSensorTemperature	The backend provides the pressure sensor’s die temperature

The features of all orientable sensors are:

Constant	Description
QSensor.AxesOrientation	The backend supports changing the axes orientation from the default of `FixedOrientation` to something else.

See also

isFeatureSupported()

PySide2.QtSensors.QSensor.AxesOrientationMode¶

Describes how reading values are affected by the screen orientation.

Constant	Description
QSensor.FixedOrientation	No automatic rotation is applied to the reading values.
QSensor.AutomaticOrientation	The reading values are automatically rotated based on the screen orientation.
QSensor.UserOrientation	The reading values are rotated based on the angle of the `userOrientation` property.

See also

axesOrientationMode

PySide2.QtSensors.QSensor.activeChanged()¶

PySide2.QtSensors.QSensor.addFilter(filter)¶

Parameters: filter – QSensorFilter

Add a filter to the sensor.

The sensor does not take ownership of the filter. QSensorFilter will inform the sensor if it is destroyed.

See also

QSensorFilter

PySide2.QtSensors.QSensor.alwaysOnChanged()¶

PySide2.QtSensors.QSensor.availableDataRates()¶

Return type

PySide2.QtSensors.QSensor.availableSensorsChanged()¶

PySide2.QtSensors.QSensor.axesOrientationMode()¶

Return type: AxesOrientationMode

See also

setAxesOrientationMode()

PySide2.QtSensors.QSensor.axesOrientationModeChanged(axesOrientationMode)¶

Parameters: axesOrientationMode – AxesOrientationMode

PySide2.QtSensors.QSensor.backend()¶

Return type: QSensorBackend

PySide2.QtSensors.QSensor.bufferSize()¶

Return type: int

See also

setBufferSize()

PySide2.QtSensors.QSensor.bufferSizeChanged(bufferSize)¶

Parameters: bufferSize – int

PySide2.QtSensors.QSensor.busyChanged()¶

PySide2.QtSensors.QSensor.connectToBackend()¶

Return type: bool

Try to connect to a sensor backend.

Returns true if a suitable backend could be found, false otherwise.

The type must be set before calling this method if you are using QSensor directly.

See also

isConnectedToBackend()

PySide2.QtSensors.QSensor.currentOrientation()¶

Return type: int

See also

setCurrentOrientation()

PySide2.QtSensors.QSensor.currentOrientationChanged(currentOrientation)¶

Parameters: currentOrientation – int

PySide2.QtSensors.QSensor.dataRate()¶

Return type: int

See also

setDataRate()

PySide2.QtSensors.QSensor.dataRateChanged()¶

static PySide2.QtSensors.QSensor.defaultSensorForType(type)¶

Parameters: type – QByteArray
Return type: QByteArray

Returns the default sensor identifier for type . This is set in a config file and can be overridden if required. If no default is available the system will return the first registered sensor for type .

Note that there is special case logic to prevent the generic plugin’s backends from becoming the default when another backend is registered for the same type. This logic means that a backend identifier starting with generic. will only be the default if no other backends have been registered for that type or if it is specified in Sensors.conf .

PySide2.QtSensors.QSensor.description()¶

Return type: unicode

PySide2.QtSensors.QSensor.efficientBufferSize()¶

Return type: int

See also

setEfficientBufferSize()

PySide2.QtSensors.QSensor.efficientBufferSizeChanged(efficientBufferSize)¶

Parameters: efficientBufferSize – int

PySide2.QtSensors.QSensor.error()¶

Return type: int

PySide2.QtSensors.QSensor.filters()¶

Return type

Returns the filters currently attached to the sensor.

See also

QSensorFilter

PySide2.QtSensors.QSensor.identifier()¶

Return type: QByteArray

See also

setIdentifier()

PySide2.QtSensors.QSensor.isActive()¶

Return type: bool

PySide2.QtSensors.QSensor.isAlwaysOn()¶

Return type: bool

PySide2.QtSensors.QSensor.isBusy()¶

Return type: bool

PySide2.QtSensors.QSensor.isConnectedToBackend()¶

Return type: bool

PySide2.QtSensors.QSensor.isFeatureSupported(feature)¶

Parameters: feature – Feature
Return type: bool

Checks if a specific feature is supported by the backend.

QtSensors supports a rich API for controlling and providing information about sensors. Naturally, not all of this functionality can be supported by all of the backends.

To check if the current backend supports the feature feature , call this function.

The backend needs to be connected, otherwise false will be returned. Calling connectToBackend() or start() will create a connection to the backend.

Backends have to implement isFeatureSupported() to make this work.

Returns whether or not the feature is supported if the backend is connected, or false if the backend is not connected.

PySide2.QtSensors.QSensor.maxBufferSize()¶

Return type: int

See also

setMaxBufferSize()

PySide2.QtSensors.QSensor.maxBufferSizeChanged(maxBufferSize)¶

Parameters: maxBufferSize – int

PySide2.QtSensors.QSensor.outputRange()¶

Return type: int

See also

setOutputRange()

PySide2.QtSensors.QSensor.outputRanges()¶

Return type

PySide2.QtSensors.QSensor.reading()¶

Return type: QSensorReading

PySide2.QtSensors.QSensor.readingChanged()¶

PySide2.QtSensors.QSensor.removeFilter(filter)¶

Parameters: filter – QSensorFilter

Remove filter from the sensor.

See also

QSensorFilter

PySide2.QtSensors.QSensor.sensorError(error)¶

Parameters: error – int

static PySide2.QtSensors.QSensor.sensorTypes()¶

Return type

Returns a list of all sensor types.

static PySide2.QtSensors.QSensor.sensorsForType(type)¶

Parameters: type – QByteArray
Return type

Returns a list of ids for each of the sensors for type . If there are no sensors of that type available the list will be empty.

PySide2.QtSensors.QSensor.setActive(active)¶

Parameters: active – bool

See also

isActive()

PySide2.QtSensors.QSensor.setAlwaysOn(alwaysOn)¶

Parameters: alwaysOn – bool

See also

isAlwaysOn()

PySide2.QtSensors.QSensor.setAxesOrientationMode(axesOrientationMode)¶

Parameters: axesOrientationMode – AxesOrientationMode

See also

axesOrientationMode()

PySide2.QtSensors.QSensor.setBufferSize(bufferSize)¶

Parameters: bufferSize – int

See also

bufferSize()

PySide2.QtSensors.QSensor.setCurrentOrientation(currentOrientation)¶

Parameters: currentOrientation – int

Sets the current screen orientation to currentOrientation . This is to be called from the backend whenever the screen orientation or the userOrientation property changes.

See also

currentOrientation()

PySide2.QtSensors.QSensor.setDataRate(rate)¶

Parameters: rate – int

See also

dataRate()

PySide2.QtSensors.QSensor.setEfficientBufferSize(efficientBufferSize)¶

Parameters: efficientBufferSize – int

Sets the efficient buffer size to efficientBufferSize . This is to be called from the backend.

See also

efficientBufferSize()

PySide2.QtSensors.QSensor.setIdentifier(identifier)¶

Parameters: identifier – QByteArray

See also

identifier()

PySide2.QtSensors.QSensor.setMaxBufferSize(maxBufferSize)¶

Parameters: maxBufferSize – int

Sets the maximum buffer size to maxBufferSize . This is to be called from the backend.

See also

maxBufferSize()

PySide2.QtSensors.QSensor.setOutputRange(index)¶

Parameters: index – int

See also

outputRange()

PySide2.QtSensors.QSensor.setSkipDuplicates(skipDuplicates)¶

Parameters: skipDuplicates – bool

Sets the duplicate skipping to skipDuplicates .

See also

skipDuplicates()

PySide2.QtSensors.QSensor.setUserOrientation(userOrientation)¶

Parameters: userOrientation – int

See also

userOrientation()

PySide2.QtSensors.QSensor.skipDuplicates()¶

Return type: bool

See also

setSkipDuplicates()

PySide2.QtSensors.QSensor.skipDuplicatesChanged(skipDuplicates)¶

Parameters: skipDuplicates – bool

PySide2.QtSensors.QSensor.start()¶

Return type: bool

Start retrieving values from the sensor. Returns true if the sensor was started, false otherwise.

The sensor may fail to start for several reasons.

Once an application has started a sensor it must wait until the sensor receives a new value before it can query the sensor’s values. This is due to how the sensor receives values from the system. Sensors do not (in general) poll for new values, rather new values are pushed to the sensors as they happen.

For example, this code will not work as intended.

sensor->start();
sensor->reading()->x(); // no data available

To work correctly, the code that accesses the reading should ensure the readingChanged() signal has been emitted.

    connect(sensor, SIGNAL(readingChanged()), this, SLOT(checkReading()));
    sensor->start();
}
void MyClass::checkReading() {
    sensor->reading()->x();

See also

busy

PySide2.QtSensors.QSensor.stop()¶

Stop retrieving values from the sensor.

This releases the sensor so that other processes can use it.

See also

busy

PySide2.QtSensors.QSensor.type()¶

Return type: QByteArray

PySide2.QtSensors.QSensor.userOrientation()¶

Return type: int

See also

setUserOrientation()

PySide2.QtSensors.QSensor.userOrientationChanged(userOrientation)¶

Parameters: userOrientation – int

Qt Documentation

Table of Contents

QSensor¶

Synopsis¶

Functions¶

Slots¶

Signals¶

Static functions¶

Detailed Description¶

Orientation¶