ioio.lib.api

Interface DigitalInput

All Superinterfaces:

Closeable

public interface DigitalInput
extends Closeable

A pin used for digital input.

A digital input pin can be used to read logic-level signals. DigitalInput instances are obtained by calling IOIO.openDigitalInput(DigitalInput.Spec).

The value of the pin is obtained by calling read(). It is also possible for the client to block until a certain level is sensed, by using waitForValue(boolean).

The instance is alive since its creation. The first read() call block for a few milliseconds until the initial value is updated. If the connection with the IOIO drops at any point, the instance transitions to a disconnected state, in which every attempt to use the pin (except Closeable.close()) will throw a ConnectionLostException. Whenever Closeable.close() is invoked the instance may no longer be used. Any resources associated with it are freed and can be reused.

Typical usage:

 DigitalInput button = ioio.openDigitalInput(10);  // used an external pull-up
 button.waitForValue(false);  // wait for press
 ...
 button.close();  // pin 10 can now be used for something else.
 

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	DigitalInput.Spec A digital input pin specification, used when opening digital inputs.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	read() Read the value sensed on the pin.
void	waitForValue(boolean value) Block until a desired logical level is sensed.

Methods inherited from interface ioio.lib.api.Closeable

close

Method Detail

read

boolean read()
             throws java.lang.InterruptedException,
                    ConnectionLostException

Read the value sensed on the pin. May block for a few milliseconds if called right after creation of the instance. If this is a problem, the calling thread may be interrupted.

Returns:

True for logical "HIGH", false for logical "LOW".

Throws:

java.lang.InterruptedException - The calling thread has been interrupted.

ConnectionLostException - The connection with the IOIO has been lost.

waitForValue

void waitForValue(boolean value)
                  throws java.lang.InterruptedException,
                         ConnectionLostException

Block until a desired logical level is sensed. The calling thread can be interrupted for aborting this operation.

Parameters:

value - The desired logical level. true for "HIGH", false for "LOW".

Throws:

java.lang.InterruptedException - The calling thread has been interrupted.

ConnectionLostException - The connection with the IOIO has been lost.