Package com.diozero.devices

Class LED

java.lang.Object

com.diozero.api.GpioDevice

com.diozero.api.DigitalOutputDevice

com.diozero.devices.LED

All Implemented Interfaces:

DeviceInterface, OutputDeviceInterface, AutoCloseable

public class LED
extends DigitalOutputDevice

Provides utility methods for controlling a Light Emitting Diode (LED). Connect the cathode (short leg, flat side) of the LED to a ground pin; connect the anode (longer leg) to a limiting resistor; connect the other side of the limiting resistor to a GPIO pin (the limiting resistor can be placed either side of the LED). Example LED control, taken from LEDTest:

 
try (LED led = new LED(pin)) {
	led.on();
	SleepUtil.sleepSeconds(.5);
	led.off();
	SleepUtil.sleepSeconds(.5);
	led.toggle();
	SleepUtil.sleepSeconds(.5);
	led.toggle();
	SleepUtil.sleepSeconds(.5);
	led.blink(0.5f, 0.5f, 10, false);
}
 

Field Summary

Fields inherited from class com.diozero.api.DigitalOutputDevice

INFINITE_ITERATIONS

Fields inherited from class com.diozero.api.GpioDevice

pinInfo

Constructor Summary

Constructors

Constructor	Description
LED(int gpio)
LED(int gpio, boolean activeHigh)
LED(PinInfo pinInfo, boolean activeHigh, boolean initialValue)
LED(GpioDeviceFactoryInterface deviceFactory, int gpio)
LED(GpioDeviceFactoryInterface deviceFactory, int gpio, boolean activeHigh, boolean initialValue)

Method Summary

Modifier and Type	Method	Description
void	blink()	Blink indefinitely with 1 second on and 1 second off.
void	blink(float onTime, float offTime, int n, boolean background)	Blink.
void	blink(float onTime, float offTime, int n, boolean background, Action stopAction)	Blink.
void	blink(Action stopAction)	Blink indefinitely with 1 second on and 1 second off.
boolean	isLit()	Return true if the LED is currently on.

Methods inherited from class com.diozero.api.DigitalOutputDevice

close, isOn, off, on, onOffLoop, setOn, setValue, setValueUnsafe, toggle

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

Constructor Details

LED

public LED(PinInfo pinInfo,
boolean activeHigh,
boolean initialValue)
    throws RuntimeIOException

Parameters:

pinInfo - GPIO to which the LED is connected.

activeHigh - Set to true if a high output value represents on.

initialValue - Initial value.

Throws:

RuntimeIOException - If an I/O error occurred.

LED

public LED(int gpio)
    throws RuntimeIOException

Parameters:

gpio - GPIO to which the LED is connected.

Throws:

RuntimeIOException - If an I/O error occurred.

LED

public LED(int gpio,
boolean activeHigh)
    throws RuntimeIOException

Parameters:

gpio - GPIO to which the LED is connected.

activeHigh - Set to true if a high output value represents on.

Throws:

RuntimeIOException - If an I/O error occurred.

LED

public LED(GpioDeviceFactoryInterface deviceFactory,
int gpio)
    throws RuntimeIOException

Parameters:

deviceFactory - Device factory to use to construct the device.

gpio - GPIO to which the LED is connected.

Throws:

RuntimeIOException - If an I/O error occurred.

LED

public LED(GpioDeviceFactoryInterface deviceFactory,
int gpio,
boolean activeHigh,
boolean initialValue)

Parameters:

deviceFactory - Device factory to use to construct the device.

gpio - GPIO to which the LED is connected.

activeHigh - Set to true if a high output value represents on.

initialValue - Initial value.

Throws:

RuntimeIOException - If an I/O error occurred.

Method Details

blink

public void blink()
           throws RuntimeIOException

Blink indefinitely with 1 second on and 1 second off.

Throws:

RuntimeIOException - If an I/O error occurred.

blink

public void blink(Action stopAction)
           throws RuntimeIOException

Blink indefinitely with 1 second on and 1 second off.

Parameters:

stopAction - Action to invoke when the animation stops.

Throws:

RuntimeIOException - If an I/O error occurred.

blink

public void blink(float onTime,
float offTime,
int n,
boolean background)
           throws RuntimeIOException

Blink.

Parameters:

onTime - On time in seconds.

offTime - Off time in seconds.

n - Number of iterations. Set to <0 to blink indefinitely.

background - If true start a background thread to control the blink and return immediately. If false, only return once the blink iterations have finished.

Throws:

RuntimeIOException - If an I/O error occurred.

blink

public void blink(float onTime,
float offTime,
int n,
boolean background,
Action stopAction)
           throws RuntimeIOException

Blink.

Parameters:

onTime - On time in seconds.

offTime - Off time in seconds.

n - Number of iterations. Set to <0 to blink indefinitely.

background - If true start a background thread to control the blink and return immediately. If false, only return once the blink iterations have finished.

stopAction - Action to invoke when the animation stops.

Throws:

RuntimeIOException - If an I/O error occurred.

isLit

public boolean isLit()
              throws RuntimeIOException

Return true if the LED is currently on.

Returns:

True if the LED is on, false if off.

Throws:

RuntimeIOException - If an I/O error occurred.