Package com.diozero.api

Class SmoothedInputDevice

java.lang.Object

com.diozero.api.GpioDevice

com.diozero.api.GpioInputDevice<DigitalInputEvent>

com.diozero.api.AbstractDigitalInputDevice

com.diozero.api.DigitalInputDevice

com.diozero.api.WaitableDigitalInputDevice

com.diozero.api.SmoothedInputDevice

All Implemented Interfaces:

DigitalInputDeviceInterface, DeviceEventConsumer<DigitalInputEvent>, Closeable, AutoCloseable, Consumer<DigitalInputEvent>

Direct Known Subclasses:

MotionSensor

public class SmoothedInputDevice
extends WaitableDigitalInputDevice

Represents a generic input device which takes its value from the number of active events over a specific time period.

This class extends WaitableDigitalInputDevice with a queue which is added to whenever the input device is active. The number of the active events in the queue is compared to a threshold which is used to determine the state of the 'active' property.

Any active events over the specified eventAge are removed by a background thread.

This class is intended for use with devices which exhibit "twitchy" behaviour (such as certain motion sensors).

Field Summary

Fields inherited from class com.diozero.api.DigitalInputDevice

device

Fields inherited from class com.diozero.api.AbstractDigitalInputDevice

activeHigh

Fields inherited from class com.diozero.api.GpioDevice

gpio

Constructor Summary

Constructors

Constructor	Description
SmoothedInputDevice(int gpio, GpioPullUpDown pud, int threshold, int eventAge, int eventDetectPeriod)
SmoothedInputDevice(GpioDeviceFactoryInterface deviceFactory, int gpio, GpioPullUpDown pud, int threshold, int eventAge, int eventDetectPeriod)

Method Summary

Modifier and Type	Method	Description
void	accept(DigitalInputEvent event)
int	getEventAge()	The time in milliseconds to keep items in the queue.
int	getEventDetectPeriod()	How frequently (in milliseconds) to check the state of the queue.
int	getThreshold()	If the number of on events younger than eventAge exceeds this amount, then 'isActive' will return 'True'.
void	setEventAge(int eventAge)	Set the event age (milliseconds).
void	setThreshold(int threshold)	Set the threshold value in terms of number of on events within the specified time period that will trigger an on event to any listeners.

Methods inherited from class com.diozero.api.WaitableDigitalInputDevice

disableDeviceListener, waitForActive, waitForActive, waitForInactive, waitForInactive, waitForValue

Methods inherited from class com.diozero.api.DigitalInputDevice

close, getPullUpDown, getTrigger, getValue, isActive, removeListener, setListener

Methods inherited from class com.diozero.api.AbstractDigitalInputDevice

enableDeviceListener, isActiveHigh, whenActivated, whenDeactivated

Methods inherited from class com.diozero.api.GpioInputDevice

addListener, removeAllListeners, removeListener

Methods inherited from class com.diozero.api.GpioDevice

getGpio

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Consumer

andThen

Constructor Details

SmoothedInputDevice

public SmoothedInputDevice(int gpio,
GpioPullUpDown pud,
int threshold,
int eventAge,
int eventDetectPeriod)
                    throws RuntimeIOException

Parameters:

gpio - GPIO to which the device is connected.

pud - Pull up/down configuration, values: NONE, PULL_UP, PULL_DOWN.

threshold - The value above which the device will be considered "on".

eventAge - The time in milliseconds to keep active events in the queue.

eventDetectPeriod - How frequently to check for events.

Throws:

RuntimeIOException - if an I/O error occurs

SmoothedInputDevice

public SmoothedInputDevice(GpioDeviceFactoryInterface deviceFactory,
int gpio,
GpioPullUpDown pud,
int threshold,
int eventAge,
int eventDetectPeriod)
                    throws RuntimeIOException

Parameters:

deviceFactory - Device factory to use to provision this device.

gpio - GPIO to which the device is connected.

pud - Pull up/down configuration, values: NONE, PULL_UP, PULL_DOWN.

threshold - The value above which the device will be considered "on".

eventAge - The time in milliseconds to keep active events in the queue.

eventDetectPeriod - How frequently to check for events.

Throws:

RuntimeIOException - if an I/O error occurs

Method Details

accept

public void accept(DigitalInputEvent event)

Specified by:

accept in interface Consumer<DigitalInputEvent>

Overrides:

accept in class WaitableDigitalInputDevice

getThreshold

public int getThreshold()

If the number of on events younger than eventAge exceeds this amount, then 'isActive' will return 'True'.

Returns:

event threshold

setThreshold

public void setThreshold(int threshold)

Set the threshold value in terms of number of on events within the specified time period that will trigger an on event to any listeners.

Parameters:

threshold - New threshold value.

getEventAge

public int getEventAge()

The time in milliseconds to keep items in the queue.

Returns:

The event age (milliseconds).

setEventAge

public void setEventAge(int eventAge)

Set the event age (milliseconds).

Parameters:

eventAge - New event age value (milliseconds).

getEventDetectPeriod

public int getEventDetectPeriod()

How frequently (in milliseconds) to check the state of the queue.

Returns:

The event detection period (milliseconds)