Module com.pi4j.crowpi

Package com.pi4j.crowpi.components

Class IrReceiverComponent

java.lang.Object

com.pi4j.crowpi.components.Component

com.pi4j.crowpi.components.IrReceiverComponent

public class IrReceiverComponent
extends Component

Implementation of the CrowPi IR receiver /not/ using GPIO with Pi4J

Unfortunately the tight timing constraints of the infrared receiver which are in the area of microseconds can not be handled by the JVM. While Pi4J does not drop any event and still processes them reliably, the timing is too far off to be useful for any signal processing. As the bundled IR remote of the CrowPi can be used as a great input device, this class provides an alternative without Pi4J.

The binary `mode2` provided by the LIRC software package is being used to record the pulses of the IR transmitter / remote. This implementation will automatically run `mode2` pointed towards a `lirc` kernel device and parses its output to recognize IR signals. While receiving the pulses is done outside of Java, all the processing and handling is still being covered as part of this class.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	IrReceiverComponent.Key	Enumeration which represents all known keycodes for the bundled CrowPi IR remote
protected final class	IrReceiverComponent.PollerManager	Poller manager class which implements Runnable and should be ran in a separate thread.
protected static interface	IrReceiverComponent.PollerProcess	Custom interface as an alternative to the Java native Process interface.
protected static interface	IrReceiverComponent.PollerProcessFactory	Functional interface for a poller process factory which creates new IrReceiverComponent.PollerProcess instances on demand.

Field Summary

Fields

Modifier and Type	Field	Description
protected IrReceiverComponent.PollerProcessFactory	pollerProcessFactory	Default poller process factory, should only be changed during tests for proper mocking.

Fields inherited from class com.pi4j.crowpi.components.Component

logger

Constructor Summary

Constructors

Constructor	Description
IrReceiverComponent()	Creates a new IR receiver using the default binary and kernel device path.
IrReceiverComponent(String mode2Binary, String devicePath)	Creates a new IR receiver using a custom mode2 binary and kernel device path.

Method Summary

Modifier and Type	Method	Description
protected IrReceiverComponent.PollerManager	getPollerManager()	Returns the instance of the poller manager or null if currently not running.
protected Thread	getPollerManagerThread()	Returns the instance of the poller manager thread or null if currently not running.
void	onKeyPressed(EventHandler<IrReceiverComponent.Key> handler)	Sets or disables the handler for received IR key presses.

Methods inherited from class com.pi4j.crowpi.components.Component

sleep, triggerSimpleEvent

Methods inherited from class java.lang.Object

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

Field Details

pollerProcessFactory

protected IrReceiverComponent.PollerProcessFactory pollerProcessFactory

Default poller process factory, should only be changed during tests for proper mocking.

Constructor Details

IrReceiverComponent

public IrReceiverComponent()

Creates a new IR receiver using the default binary and kernel device path.

IrReceiverComponent

public IrReceiverComponent(String mode2Binary,
 String devicePath)

Creates a new IR receiver using a custom mode2 binary and kernel device path.

Parameters:

mode2Binary - Path to `mode2` binary provided by LIRC

devicePath - Absolute path to kernel device, e.g. /dev/lirc0

Method Details

onKeyPressed

public void onKeyPressed(EventHandler<IrReceiverComponent.Key> handler)

Sets or disables the handler for received IR key presses. This will automatically start or stop the poller as needed.

Parameters:

handler - Event handler to call or null to disable

getPollerManager

protected IrReceiverComponent.PollerManager getPollerManager()

Returns the instance of the poller manager or null if currently not running.

Returns:

Poller manager instance or null

getPollerManagerThread

protected Thread getPollerManagerThread()

Returns the instance of the poller manager thread or null if currently not running.

Returns:

Poller manager thread or null