Package edu.wpi.first.wpilibj

Class Relay

java.lang.Object

edu.wpi.first.wpilibj.MotorSafety

edu.wpi.first.wpilibj.Relay

All Implemented Interfaces:

Sendable, AutoCloseable

public class Relay
extends MotorSafety
implements Sendable, AutoCloseable

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	Description
static class	Relay.Direction	The Direction(s) that a relay is configured to operate in.
static 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.

Constructor Summary

Constructors

Constructor	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	Description
void	close()
Relay.Value	get()	Get the Relay State.
int	getChannel()	Get the channel number.
String	getDescription()
void	initSendable(SendableBuilder builder)	Initializes this Sendable object.
void	set(Relay.Value value)	Set the relay state.
void	setDirection(Relay.Direction direction)	Set the Relay Direction.
void	stopMotor()

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

check, checkMotors, feed, getExpiration, isAlive, isSafetyEnabled, setExpiration, setSafetyEnabled

Methods inherited from class java.lang.Object

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

Constructor Details

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 Details

close

public void close()

Specified by:

close in interface AutoCloseable

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.

stopMotor

public void stopMotor()

Specified by:

stopMotor in class MotorSafety

getDescription

public String getDescription()

Specified by:

getDescription in class 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