Package lejos.hardware.sensor

Class RCXRotationSensor

java.lang.Object

lejos.hardware.Device

lejos.hardware.sensor.BaseSensor

lejos.hardware.sensor.AnalogSensor

lejos.hardware.sensor.RCXRotationSensor

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, SensorConstants, SensorMode, SensorModes, Encoder, SampleProvider, Tachometer

public class RCXRotationSensor
extends AnalogSensor
implements Tachometer, SensorConstants

Provide access to the Lego RCX Rotation Sensor. The sensor records the direction and degree of rotation. A full rotation will result in a count of +/-16. Thus each count is 22.5 degrees.

Author:

Andy Shaw

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	RCXRotationSensor.Reader

Field Summary

Fields

Modifier and Type	Field	Description
protected int	count
protected static int[][]	inc	The following table when indexed by [previous phase][current phase] provides the current direction of rotation.
static int	ONE_ROTATION	The incremental count for one whole rotation (360 degrees).
protected RCXRotationSensor.Reader	reader
protected static int	UPDATE_TIME

Fields inherited from class lejos.hardware.sensor.AnalogSensor

currentType, port

Fields inherited from class lejos.hardware.sensor.BaseSensor

currentMode, modes

Fields inherited from class lejos.hardware.Device

closeList

Fields inherited from interface lejos.hardware.sensor.SensorConstants

BLACK, BLANK_INDEX, BLUE, BLUE_INDEX, BROWN, GREEN, GREEN_INDEX, MAX_TYPE, MIN_TYPE, MODE_RAW, NXT_ADC_RES, RED, RED_INDEX, TYPE_ANGLE, TYPE_COLORBLUE, TYPE_COLORFULL, TYPE_COLORGREEN, TYPE_COLORNONE, TYPE_COLORRED, TYPE_CUSTOM, TYPE_HIGHSPEED, TYPE_HIGHSPEED_9V, TYPE_HISPEED, TYPE_LIGHT_ACTIVE, TYPE_LIGHT_INACTIVE, TYPE_LOWSPEED, TYPE_LOWSPEED_9V, TYPE_NO_SENSOR, TYPE_REFLECTION, TYPE_SOUND_DB, TYPE_SOUND_DBA, TYPE_SWITCH, TYPE_TEMPERATURE, WHITE, YELLOW

Constructor Summary

Constructors

Constructor	Description
RCXRotationSensor(Port p)	Create an RCX rotation sensor object attached to the specified port.

Method Summary

Modifier and Type	Method	Description
protected int	getPhase()	Returns the current phase of the sensor.
int	getRawTachoCount()	Returns the raw values from the rotation sensor instead of degrees.
int	getRotationSpeed()	Returns the actual speed.
int	getTachoCount()	Returns the tachometer count.
void	resetTachoCount()	Reset the tacho count to zero.

Methods inherited from class lejos.hardware.sensor.AnalogSensor

normalize, NXTRawIntValue, NXTRawValue, switchType

Methods inherited from class lejos.hardware.sensor.BaseSensor

fetchSample, getAvailableModes, getCurrentMode, getMode, getMode, getModeCount, getName, sampleSize, setCurrentMode, setCurrentMode, setModes

Methods inherited from class lejos.hardware.Device

close, releaseOnClose

Methods inherited from class java.lang.Object

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

Field Detail

ONE_ROTATION

public static final int ONE_ROTATION

The incremental count for one whole rotation (360 degrees).

See Also:

Constant Field Values

UPDATE_TIME

protected static final int UPDATE_TIME

See Also:

Constant Field Values

count

protected int count

reader

protected final RCXRotationSensor.Reader reader

inc

protected static final int[][] inc

The following table when indexed by [previous phase][current phase] provides the current direction of rotation. Invalid phase combinations result in zero.

Constructor Detail

RCXRotationSensor

public RCXRotationSensor(Port p)

Create an RCX rotation sensor object attached to the specified port.

Parameters:

p - port, e.g. Port.S1

Method Detail

getPhase

protected int getPhase()

Returns the current phase of the sensor. The sensor returns four distinct values read by the ADC port. Each value represents a phase in the rotation. The sequence of the phases is: 0 1 3 2 and 0 2 3 1 The transition from one phase to another can be used to identify the direction of rotation.

Returns:

the current rotation phase.

getTachoCount

public int getTachoCount()

Returns the tachometer count. NOTE: Because the RCX rotation sensor only counts 16 increments for a full rotation, the degree values are only accurate to +- 22.5 degrees.

Specified by:

getTachoCount in interface Encoder

Returns:

tachometer count in degrees, in increments of 22.5 degrees (rounded off)

getRawTachoCount

public int getRawTachoCount()

Returns the raw values from the rotation sensor instead of degrees. A full rotation of 360 degrees results in count increasing by 16.

Returns:

the raw tachometer reading

resetTachoCount

public void resetTachoCount()

Reset the tacho count to zero.

Specified by:

resetTachoCount in interface Encoder

getRotationSpeed

public int getRotationSpeed()

Description copied from interface: Tachometer

Returns the actual speed.

Specified by:

getRotationSpeed in interface Tachometer

Returns:

speed in degrees per second, negative value means motor is rotating backward