edu.wpi.first.wpilibj

Class Relay

java.lang.Object

edu.wpi.first.wpilibj.SendableBase

edu.wpi.first.wpilibj.Relay

All Implemented Interfaces:

MotorSafety, Sendable

public class Relay
extends SendableBase
implements MotorSafety, Sendable

Class for VEX Robotics Spike style relay outputs. Relays are intended to be connected to Spikes or similar relays. The relay channels controls a pair of channels that are either both off, one on, the other on, or both on. This translates into two Spike outputs at 0v, one at 12v and one at 0v, one at 0v and the other at 12v, or two Spike outputs at 12V. This allows off, full forward, or full reverse control of motors without variable speed. It also allows the two channels (forward and reverse) to be used independently for something that does not care about voltage polarity (like a solenoid).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Relay.Direction The Direction(s) that a relay is configured to operate in.
class	Relay.InvalidValueException This class represents errors in trying to set relay values contradictory to the direction to which the relay is set.
static class	Relay.Value The state to drive a Relay to.

Field Summary

Fields inherited from interface edu.wpi.first.wpilibj.MotorSafety

DEFAULT_SAFETY_EXPIRATION

Constructor Summary

Constructors

Constructor and Description
Relay(int channel) Relay constructor given a channel, allowing both directions.
Relay(int channel, Relay.Direction direction) Relay constructor given a channel.

Method Summary

Modifier and Type	Method and Description
void	free() Free the resources used by this object.
Relay.Value	get() Get the Relay State.
int	getChannel() Get the channel number.
java.lang.String	getDescription()
double	getExpiration()
void	initSendable(SendableBuilder builder) Initializes this Sendable object.
boolean	isAlive()
boolean	isSafetyEnabled()
void	set(Relay.Value value) Set the relay state.
void	setDirection(Relay.Direction direction) Set the Relay Direction.
void	setExpiration(double timeout)
void	setSafetyEnabled(boolean enabled)
void	stopMotor()

Methods inherited from class edu.wpi.first.wpilibj.SendableBase

addChild, getName, getSubsystem, setName, setName, setName, setSubsystem

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.wpi.first.wpilibj.Sendable

getName, getSubsystem, setName, setName, setSubsystem

Constructor Detail

Relay

public Relay(int channel,
             Relay.Direction direction)

Relay constructor given a channel.

Parameters:

channel - The channel number for this relay (0 - 3).

direction - The direction that the Relay object will control.

Relay

public Relay(int channel)

Relay constructor given a channel, allowing both directions.

Parameters:

channel - The channel number for this relay (0 - 3).

Method Detail

free

public void free()

Description copied from class: SendableBase

Free the resources used by this object.

Overrides:

free in class SendableBase

set

public void set(Relay.Value value)

Set the relay state.

Valid values depend on which directions of the relay are controlled by the object.

When set to kBothDirections, the relay can be set to any of the four states: 0v-0v, 12v-0v, 0v-12v, 12v-12v

When set to kForwardOnly or kReverseOnly, you can specify the constant for the direction or you can simply specify kOff and kOn. Using only kOff and kOn is recommended.

Parameters:

value - The state to set the relay.

get

public Relay.Value get()

Get the Relay State.

Gets the current state of the relay.

When set to kForwardOnly or kReverseOnly, value is returned as kOn/kOff not kForward/kReverse (per the recommendation in Set)

Returns:

The current state of the relay as a Relay::Value

getChannel

public int getChannel()

Get the channel number.

Returns:

The channel number.

setExpiration

public void setExpiration(double timeout)

Specified by:

setExpiration in interface MotorSafety

getExpiration

public double getExpiration()

Specified by:

getExpiration in interface MotorSafety

isAlive

public boolean isAlive()

Specified by:

isAlive in interface MotorSafety

stopMotor

public void stopMotor()

Specified by:

stopMotor in interface MotorSafety

isSafetyEnabled

public boolean isSafetyEnabled()

Specified by:

isSafetyEnabled in interface MotorSafety

setSafetyEnabled

public void setSafetyEnabled(boolean enabled)

Specified by:

setSafetyEnabled in interface MotorSafety

getDescription

public java.lang.String getDescription()

Specified by:

getDescription in interface MotorSafety

setDirection

public void setDirection(Relay.Direction direction)

Set the Relay Direction.

Changes which values the relay can be set to depending on which direction is used

Valid inputs are kBothDirections, kForwardOnly, and kReverseOnly

Parameters:

direction - The direction for the relay to operate in

initSendable

public void initSendable(SendableBuilder builder)

Description copied from interface: Sendable

Initializes this Sendable object.

Specified by:

initSendable in interface Sendable

Parameters:

builder - sendable builder