org.joshvm.j2me.dio.gpio

Interface GPIOPin

All Superinterfaces:

Device

public interface GPIOPin
extends Device

Field Summary

Fields

Modifier and Type	Field and Description
static int	INPUT Input port direction.
static int	OUTPUT Output port direction.

Fields inherited from interface org.joshvm.j2me.dio.Device

BIG_ENDIAN, LITTLE_ENDIAN, MIXED_ENDIAN

Method Summary

Methods

Modifier and Type	Method and Description
int	getDirection() Returns the current direction of this GPIO pin.
int	getTrigger() Returns the current pin interrupt trigger.
boolean	getValue() Returns the current value of this GPIO pin.
void	setDirection(int direction) Sets this GPIO pin for output or input.
void	setInputListener(PinListener listener) Registers a PinListener instance which will get asynchronously notified when this GPIO pin's value changes and according to the current trigger mode (see getTrigger).
void	setTrigger(int trigger) Sets this GPIO pin trigger mode.
void	setValue(boolean value) Sets the value of this GPIO pin.

Methods inherited from interface org.joshvm.j2me.dio.Device

close, isOpen, tryLock, unlock

Field Detail

INPUT

static final int INPUT

Input port direction.

See Also:

Constant Field Values

OUTPUT

static final int OUTPUT

Output port direction.

See Also:

Constant Field Values

Method Detail

getDirection

int getDirection()
                 throws IOException,
                        UnavailableDeviceException,
                        ClosedDeviceException

Returns the current direction of this GPIO pin. If the direction was not set previously using setDirection the device configuration-specific default value is returned.

Returns:

OUTPUT if this GPIO pin is currently set as output; INPUT otherwise (the GPIO pin is set as input).

Throws:

IOException - if some other I/O error occurs.

UnavailableDeviceException - if this device is not currently available - such as it is locked by another application.

ClosedDeviceException - if the device has been closed.

getTrigger

int getTrigger()
               throws IOException,
                      UnavailableDeviceException,
                      ClosedDeviceException

Returns the current pin interrupt trigger. If the trigger mode was not set previously using setTrigger the device configuration-specific default value is returned. Setting the trigger mode to GPIOPinConfig.TRIGGER_NONE disables the notification of the PinListener instance (see setInputListener without unregistering it. The value returned by this method is unaffected by changes of the direction on a bidirectional GPIO pin.

Returns:

the current pin interrupt trigger, one of: GPIOPinConfig.TRIGGER_NONE, GPIOPinConfig.TRIGGER_FALLING_EDGE, GPIOPinConfig.TRIGGER_RISING_EDGE , GPIOPinConfig.TRIGGER_BOTH_EDGES, GPIOPinConfig.TRIGGER_HIGH_LEVEL, GPIOPinConfig.TRIGGER_LOW_LEVEL, GPIOPinConfig.TRIGGER_BOTH_LEVELS; GPIOPinConfig.TRIGGER_NONE if this GPIO pin is configured for output-only.

Throws:

IOException - if some other I/O error occurs.

UnavailableDeviceException - if this device is not currently available - such as it is locked by another application.

ClosedDeviceException - if the device has been closed.

getValue

boolean getValue()
                 throws IOException,
                        UnavailableDeviceException,
                        ClosedDeviceException

Returns the current value of this GPIO pin. If the value was not set previously using setValue the device configuration-specific default value is returned.

This method can be called on both output and input pins.

Returns:

true if this pin is currently high.

Throws:

IOException - if an I/O error occurred such as the pin is not readable.

UnavailableDeviceException - if this device is not currently available - such as it is locked by another application.

ClosedDeviceException - if the device has been closed.

setDirection

void setDirection(int direction)
                  throws IOException,
                         UnsupportedOperationException,
                         IllegalArgumentException,
                         UnavailableDeviceException,
                         ClosedDeviceException

Sets this GPIO pin for output or input. The direction can only be set to INPUT if the GPIO pin is configured for input-only (see GPIOPinConfig.DIR_INPUT_ONLY) or is configured as bidirectional (see GPIOPinConfig.DIR_BOTH_INIT_INPUT and GPIOPinConfig.DIR_BOTH_INIT_OUTPUT). The direction can only be set to OUTPUT if the GPIO pin is configured for output-only (see GPIOPinConfig.DIR_OUTPUT_ONLY) or is configured as bidirectional (see GPIOPinConfig.DIR_BOTH_INIT_INPUT and GPIOPinConfig.DIR_BOTH_INIT_OUTPUT). The value returned by getTrigger is unaffected by changes of the direction on a bidirectional GPIO pin.

Parameters:

direction - OUTPUT for output; INPUT for input.

Throws:

IOException - if some other I/O error occurs.

UnsupportedOperationException - if this GPIO pin cannot be configured for the desired direction.

IllegalArgumentException - if direction is not equal to OUTPUT or INPUT.

UnavailableDeviceException - if this device is not currently available - such as it is locked by another application.

ClosedDeviceException - if the device has been closed.

setTrigger

void setTrigger(int trigger)
                throws IOException,
                       UnsupportedOperationException,
                       IllegalArgumentException,
                       UnavailableDeviceException,
                       ClosedDeviceException

Sets this GPIO pin trigger mode. Setting the trigger mode to GPIOPinConfig.TRIGGER_NONE disables the notification of the PinListener instance (see setInputListener without unregistering it.

Parameters:

trigger - the interrupt trigger events, one of: GPIOPinConfig.TRIGGER_NONE, GPIOPinConfig.TRIGGER_FALLING_EDGE, GPIOPinConfig.TRIGGER_RISING_EDGE, GPIOPinConfig.TRIGGER_BOTH_EDGES, GPIOPinConfig.TRIGGER_HIGH_LEVEL , GPIOPinConfig.TRIGGER_LOW_LEVEL, GPIOPinConfig.TRIGGER_BOTH_LEVELS.

Throws:

IOException - if an IO error occurred.

UnsupportedOperationException - if this GPIO pin is currently configured for output or cannot otherwise be configured with the desired trigger mode.

IllegalArgumentException - if trigger is not one of the defined values.

UnavailableDeviceException - if this device is not currently available - such as it is locked by another application.

ClosedDeviceException - if the device has been closed.

setInputListener

void setInputListener(PinListener listener)
                      throws IOException,
                             UnsupportedOperationException,
                             IllegalStateException,
                             ClosedDeviceException

Registers a PinListener instance which will get asynchronously notified when this GPIO pin's value changes and according to the current trigger mode (see getTrigger). Notification will automatically begin after registration completes.

If this GPIOPin is open in DeviceManager.SHARED access mode and if this GPIOPin is currently configured for input, the listeners registered by all the applications sharing the underlying GPIO pin will get notified when its value changes.

A listener can only be registered for a GPIO pin currently configured for input.

If listener is null then the previously registered listener is removed.

Only one listener can be registered at a particular time.

Parameters:

listener - the PinListener instance to be notified when this GPIO pin's value changes.

Throws:

IOException - if some other I/O error occurs.

UnsupportedOperationException - if this GPIO pin is currently configured for output.

IllegalStateException - if listener is not null and a listener is already registered.

ClosedDeviceException - if the device has been closed.

setValue

void setValue(boolean value)
              throws IOException,
                     UnsupportedOperationException,
                     UnavailableDeviceException,
                     ClosedDeviceException

Sets the value of this GPIO pin.

An attempt to set the value on a GPIO pin currently configured for input will result in a UnsupportedOperationException being thrown.

Parameters:

value - the new pin value: true for high, false for low.

Throws:

UnsupportedOperationException - if trying to set the value for pin configured for input.

IOException - if an I/O error occurred such as the pin is not writable.

UnavailableDeviceException - if this device is not currently available - such as it is locked by another application.

ClosedDeviceException - if the device has been closed.