Package lejos.hardware.sensor

Class EV3IRSensor

java.lang.Object

lejos.hardware.Device

lejos.hardware.sensor.BaseSensor

lejos.hardware.sensor.UARTSensor

lejos.hardware.sensor.EV3IRSensor

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, SensorMode, SensorModes, SampleProvider

public class EV3IRSensor
extends UARTSensor

EV3 Infra Red sensor
The digital EV3 Infrared Seeking Sensor detects proximity to the robot and reads signals emitted by the EV3 Infrared Beacon. The sensor can alse be used as a receiver for a Lego Ev3 IR remote control.

Supported modes
Mode name	Description	unit(s)	Getter
Distance	Measures the distance to an object in front of the sensor	Undefined	getDistanceMode()
Seek	Locates up to four beacons	Undefined, undefined	getSeekMode()

EV3 Infra Red sensor
The sensor can be used as a receiver for up to four Lego Ev3 IR remote controls using the getRemoteCommand(int) and getRemoteCommands(byte[], int, int) methods. See Sensor Product page See The leJOS sensor framework See leJOS conventions for SampleProviders

Author:

andy

Field Summary

Fields

Modifier and Type	Field	Description
static int	IR_CHANNELS
protected static int	IR_PROX
protected static int	IR_REMOTE
protected static int	IR_SEEK
protected byte[]	remoteVals
protected static int	SWITCH_DELAY

Fields inherited from class lejos.hardware.sensor.UARTSensor

currentMode, port

Fields inherited from class lejos.hardware.sensor.BaseSensor

modes

Fields inherited from class lejos.hardware.Device

closeList

Constructor Summary

Constructors

Constructor	Description
EV3IRSensor(Port port)
EV3IRSensor(UARTPort port)

Method Summary

Modifier and Type	Method	Description
SensorMode	getDistanceMode()	EV3 Infra Red sensor, Distance mode Measures the distance to an object in front of the sensor.
int	getRemoteCommand(int chan)	Return the current remote command from the specified channel.
void	getRemoteCommands(byte[] cmds, int offset, int len)	Obtain the commands associated with one or more channels.
SensorMode	getSeekMode()	EV3 Infra Red sensor, Seek mode In seek mode the sensor locates up to four beacons and provides bearing and distance of each beacon.
protected void	init()

Methods inherited from class lejos.hardware.sensor.UARTSensor

switchMode

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

IR_PROX

protected static final int IR_PROX

See Also:

Constant Field Values

IR_SEEK

protected static final int IR_SEEK

See Also:

Constant Field Values

IR_REMOTE

protected static final int IR_REMOTE

See Also:

Constant Field Values

SWITCH_DELAY

protected static final int SWITCH_DELAY

See Also:

Constant Field Values

IR_CHANNELS

public static final int IR_CHANNELS

See Also:

Constant Field Values

remoteVals

protected byte[] remoteVals

Constructor Detail

EV3IRSensor

public EV3IRSensor(UARTPort port)

EV3IRSensor

public EV3IRSensor(Port port)

Method Detail

init

protected void init()

getRemoteCommand

public int getRemoteCommand(int chan)

Return the current remote command from the specified channel. Remote commands are a single numeric value which represents which button on the Lego IR remote is currently pressed (0 means no buttons pressed). Four channels are supported (0-3) which correspond to 1-4 on the remote. The button values are:
1 TOP-LEFT
2 BOTTOM-LEFT
3 TOP-RIGHT
4 BOTTOM-RIGHT
5 TOP-LEFT + TOP-RIGHT
6 TOP-LEFT + BOTTOM-RIGHT
7 BOTTOM-LEFT + TOP-RIGHT
8 BOTTOM-LEFT + BOTTOM-RIGHT
9 CENTRE/BEACON
10 BOTTOM-LEFT + TOP-LEFT
11 TOP-RIGHT + BOTTOM-RIGHT

Parameters:

chan - channel to obtain the command for

Returns:

the current command

getRemoteCommands

public void getRemoteCommands(byte[] cmds,
                              int offset,
                              int len)

Obtain the commands associated with one or more channels. Each element of the array contains the command for the associated channel (0-3).

Parameters:

cmds - the array to store the commands

offset - the offset to start storing

len - the number of commands to store.

getDistanceMode

public SensorMode getDistanceMode()

EV3 Infra Red sensor, Distance mode
Measures the distance to an object in front of the sensor.

Size and content of the sample
The sample contains one element giving the distance to an object in front of the sensor. The distance provided is very roughly equivalent to meters but needs conversion to give better distance. See product page for details.
The effective range of the sensor in Distance mode is about 5 to 50 centimeters. Outside this range a zero is returned for low values and positive infinity for high values.

Returns:

A sampleProvider See leJOS conventions for SampleProviders See Sensor Product page

getSeekMode

public SensorMode getSeekMode()

EV3 Infra Red sensor, Seek mode
In seek mode the sensor locates up to four beacons and provides bearing and distance of each beacon.

Size and content of the sample
The sample contains four pairs of elements in a single sample. Each pair gives bearing of and distance to the beacon. The first pair of elements is associated with a beacon transmitting on channel 0, the second pair with a beacon transmitting on channel 1 etc.
The bearing values range from -25 to +25 (with values increasing clockwise when looking from behind the sensor). A bearing of 0 indicates the beacon is directly in front of the sensor.
Distance values are not to scale. Al increasing values indicate increasing distance.
If no beacon is detected both bearing is set to zero, and distance to positive infinity.

Returns:

A sampleProvider See leJOS conventions for SampleProviders See Sensor Product page