josx.platform.rcx
Class ProximitySensor

java.lang.Object
  |
  +--josx.platform.rcx.ProximitySensor

All Implemented Interfaces:

SensorListener

public class ProximitySensor

extends Object

implements SensorListener

A 'sensor' to detect object proximity. Sends a short message out of the infra-red port every so often and looks for the reflection using the light sensor (which happens to be very infra-red sensitive).

Author:

Paul Andrews

Constructor Summary

ProximitySensor(Sensor sensor)
Constructor.

ProximitySensor(Sensor sensor, int threshhold)
Constructor.

Method Summary

void	stateChanged(Sensor sensor, int oldValue, int newValue) Called from a thread private to sensor that runs at MAX_PRIORITY If newValue > oldValue by more than the threshhold, notify anything wait()ing on the sensor.
void	waitTillNear(long millis) Block the current thread until a near object is detected.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProximitySensor

public ProximitySensor(Sensor sensor)

Constructor. Threshhold defaults to 15.

Parameters:

sensor - the sensor to which the light detector is connected. the constructor will initialize the sensor and set up the infrared transmitter.

ProximitySensor

public ProximitySensor(Sensor sensor,
                       int threshhold)

Constructor.

Parameters:

sensor - the sensor to which the light detector is connected. the constructor will initialize the sensor and set up the infrared transmitter.

threshhold - the bigger the number the closer we get.

Method Detail

waitTillNear

public void waitTillNear(long millis)
                  throws InterruptedException

Block the current thread until a near object is detected. A user could simply do their own sensor.wait() as that is all this method does.

Parameters:

millis - wait at most millis milliseconds. 0 means wait forever

Throws:

InterruptedException - if some thread calls interrupt() on the calling thread.

stateChanged

public void stateChanged(Sensor sensor,
                         int oldValue,
                         int newValue)

Called from a thread private to sensor that runs at MAX_PRIORITY If newValue > oldValue by more than the threshhold, notify anything wait()ing on the sensor.

Specified by:

stateChanged in interface SensorListener

Parameters:

sensor - The sensor that generated the event.

oldValue - The old sensor value.

newValue - The new sensor value.