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// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.
#pragma once
#include <memory>
#include <string>
#include <hal/Relay.h>
#include <hal/Types.h>
#include <wpi/sendable/Sendable.h>
#include <wpi/sendable/SendableHelper.h>
#include "frc/MotorSafety.h"
namespace frc {
/**
* Class for Spike style relay outputs.
*
* Relays are intended to be connected to spikes or similar relays. The relay
* channels controls a pair of pins 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).
*/
class Relay : public MotorSafety,
public wpi::Sendable,
public wpi::SendableHelper<Relay> {
public:
/**
* The state to drive a Relay to.
*/
enum Value {
/// Off.
kOff,
/// On.
kOn,
/// Forward.
kForward,
/// Reverse.
kReverse
};
/**
* The Direction(s) that a relay is configured to operate in.
*/
enum Direction {
/// Both directions are valid.
kBothDirections,
/// Only forward is valid.
kForwardOnly,
/// Only reverse is valid.
kReverseOnly
};
/**
* Relay constructor given a channel.
*
* This code initializes the relay and reserves all resources that need to be
* locked. Initially the relay is set to both lines at 0v.
*
* @param channel The channel number (0-3).
* @param direction The direction that the Relay object will control.
*/
explicit Relay(int channel, Direction direction = kBothDirections);
Relay(Relay&&) = default;
Relay& operator=(Relay&&) = default;
/**
* Free the resource associated with a relay.
*
* The relay channels are set to free and the relay output is turned off.
*/
~Relay() override;
/**
* 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 any of the four states:
* 0v-0v, 0v-12v, 12v-0v, 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.
*
* @param value The state to set the relay.
*/
void Set(Value value);
/**
* 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).
*
* @return The current state of the relay as a Relay::Value
*/
Value Get() const;
int GetChannel() const;
// MotorSafety interface
void StopMotor() override;
std::string GetDescription() const override;
void InitSendable(wpi::SendableBuilder& builder) override;
private:
int m_channel;
Direction m_direction;
hal::Handle<HAL_RelayHandle, HAL_FreeRelayPort> m_forwardHandle;
hal::Handle<HAL_RelayHandle, HAL_FreeRelayPort> m_reverseHandle;
};
} // namespace frc