josx.platform.rcx
Class Sensor

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

All Implemented Interfaces:

ListenerCaller

public class Sensor

extends Object

implements ListenerCaller

Abstraction for a sensor (considerably changed since alpha5). There are three Sensor instances available: Sensor.S1, Sensor.S2 and Sensor.S3. They correspond to sensor inputs labeled 1, 2 and 3 in the RCX, respectively. Before using a sensor, you should set its mode and type with setTypeAndMode using constants defined in SensorConstants. You should also activate the sensor.

You can poll for sensor values in a loop using the readValue method or one of the other read methods. There is also a low level method which can be used when maximum performance is required. Another way to monitor sensor values is to add a SensorListener. All sensor events are dispatched to listeners by a single thread created by this class. The thread is a daemon thread and so will not prevent termination of an application if all other threads have exited.

Example:

   Sensor.S1.setTypeAndMode (3, 0x80);
   Sensor.S1.activate();
   Sensor.S1.addSensorListener (new SensorListener() {
     public void stateChanged (Sensor src, int oldValue, int newValue) {
       // Will be called whenever sensor value changes
       LCD.showNumber (newValue);
       try {
         Thread.sleep (100);
       } catch (InterruptedException e) {
         // ignore
       }
     }
   });
     
 

See Also:

SensorConstants, SensorListener

Field Summary

static Sensor	S1 Sensor labeled 1 on RCX.
static Sensor	S2 Sensor labeled 2 on RCX.
static Sensor	S3 Sensor labeled 3 on RCX.
static Sensor[]	SENSORS Array containing all three sensors [0..2].

Method Summary

void	activate() Activates the sensor.
void	addSensorListener(SensorListener aListener) Adds a sensor listener.
void	callListeners()
int	getId() Return the ID of the sensor.
void	passivate() Passivates the sensor.
boolean	readBooleanValue() Reads the boolean value of the sensor.
int	readRawValue() Reads the raw value of the sensor.
static int	readSensorValue(int aSensorId, int aRequestType) Low-level API for reading sensor values.
int	readValue() Reads the canonical value of the sensor.
void	setPreviousValue(int aValue) Resets the canonical sensor value.
void	setTypeAndMode(int aType, int aMode) Sets the sensor's mode and type.

Methods inherited from class java.lang.Object

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

Field Detail

S1

public static final Sensor S1

Sensor labeled 1 on RCX.

S2

public static final Sensor S2

Sensor labeled 2 on RCX.

S3

public static final Sensor S3

Sensor labeled 3 on RCX.

SENSORS

public static final Sensor[] SENSORS

Array containing all three sensors [0..2].

Method Detail

readValue

public final int readValue()

Reads the canonical value of the sensor.

readRawValue

public final int readRawValue()

Reads the raw value of the sensor.

readBooleanValue

public final boolean readBooleanValue()

Reads the boolean value of the sensor.

getId

public final int getId()

Return the ID of the sensor. One of 0, 1 or 2.

addSensorListener

public void addSensorListener(SensorListener aListener)

Adds a sensor listener.

NOTE 1: You can add at most 8 listeners.
NOTE 2: Synchronizing inside listener methods could result in a deadlock.

See Also:

SensorListener

activate

public final void activate()

Activates the sensor. This method should be called if you want to get accurate values from the sensor. In the case of light sensors, you should see the led go on when you call this method.

passivate

public final void passivate()

Passivates the sensor.

setTypeAndMode

public final void setTypeAndMode(int aType,
                                 int aMode)

Sets the sensor's mode and type. If this method isn't called, the default type is 3 (LIGHT) and the default mode is 0x80 (PERCENT).

Parameters:

aType - 0 = RAW, 1 = TOUCH, 2 = TEMP, 3 = LIGHT, 4 = ROT.

aMode - 0x00 = RAW, 0x20 = BOOL, 0x40 = EDGE, 0x60 = PULSE, 0x80 = PERCENT, 0xA0 = DEGC, 0xC0 = DEGF, 0xE0 = ANGLE. Also, mode can be OR'd with slope (0..31).

See Also:

SensorConstants

setPreviousValue

public final void setPreviousValue(int aValue)

Resets the canonical sensor value. This may be useful for rotation sensors.

readSensorValue

public static int readSensorValue(int aSensorId,
                                  int aRequestType)

Low-level API for reading sensor values.

Parameters:

aSensorId - Sensor ID (0..2).

aRequestType - 0 = raw value, 1 = canonical value, 2 = boolean value.

callListeners

public void callListeners()

Specified by:

callListeners in interface ListenerCaller