为子系统编写代码

添加代码以创建实际工作子系统非常简单。对于不使用反馈的简单子系统，结果证明非常简单。在本节中，我们将看一个 Claw 子系统的示例。 Claw 子系统还有一个限位开关来确定物体是否在抓地力中。

爪子系统的RobotBuilder表示

机械臂末端的爪子是一个由单个 VictorSPX 电机控制器控制的子系统。我们希望电机做三件事，打开，关闭和停止移动。这是子系统的责任。打开和关闭的时间将在本教程后面的指令处讨论到。我们还将定义一个方法来判断爪子是否正在抓取物体。

添加子系统功能

Java

// ROBOTBUILDER TYPE: Subsystem.

package frc.robot.subsystems;


import frc.robot.commands.*;
import edu.wpi.first.wpilibj.livewindow.LiveWindow;
import edu.wpi.first.wpilibj2.command.SubsystemBase;

// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=IMPORTS
import edu.wpi.first.wpilibj.DigitalInput;
import edu.wpi.first.wpilibj.motorcontrol.PWMVictorSPX;

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=IMPORTS


/**
 *
 */
public class Claw extends SubsystemBase {
    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS

    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
private PWMVictorSPX motor;
private DigitalInput limitswitch;

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
    
    /**
    *
    */
    public Claw() {
        // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS
motor = new PWMVictorSPX(4);
 addChild("motor",motor);
 motor.setInverted(false);

limitswitch = new DigitalInput(4);
 addChild("limit switch", limitswitch);
 


    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS
    }

    @Override
    public void periodic() {
        // This method will be called once per scheduler run

    }

    @Override
    public void simulationPeriodic() {
        // This method will be called once per scheduler run when in simulation

    }

    // Put methods for controlling this subsystem
    // here. Call these from Commands.
    
    public void open() {
        motor.set(1.0);
    }

    public void close() {
        motor.set(-1.0);
    }

    public void stop() {
        motor.set(0.0);
    }

    public boolean isGripping() {
        return limitswitch.get();
    }

}

C++

// ROBOTBUILDER TYPE: Subsystem.

// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
#include "subsystems/Claw.h"
#include <frc/smartdashboard/SmartDashboard.h>

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES

Claw::Claw(){
    SetName("Claw");
    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
    SetSubsystem("Claw");

 AddChild("limit switch", &m_limitswitch);
 

 AddChild("motor", &m_motor);
 m_motor.SetInverted(false);


    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
}

void Claw::Periodic() {
    // Put code here to be run every loop

}

void Claw::SimulationPeriodic() {
    // This method will be called once per scheduler run when in simulation

}

// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS


// Put methods for controlling this subsystem
// here. Call these from Commands.

void Claw::Open() {
    m_motor.Set(1.0);
}

void Claw::Close() {
    m_motor.Set(-1.0);
}

void Claw::Stop() {
    m_motor.Set(0.0);
}

bool Claw::IsGripping() {
    return m_limitswitch.Get();
}

将方法添加到 claw.java 或 claw.cpp 将打开，关闭和停止爪子移动并获取爪子限位开关。这些将由实际操作爪子的命令使用。

请注意，名为“motor”和“limitswitch”的成员变量是由 RobotBuilder 创建的，因此可以在整个子系统中使用。每个拖入的调色板项目都有一个成员变量，其名称在 RobotBuilder 中给出。

将方法声明添加到头文件（仅C ++）

C++

// ROBOTBUILDER TYPE: Subsystem.
#pragma once

// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
#include <frc2/command/SubsystemBase.h>
#include <frc/DigitalInput.h>
#include <frc/motorcontrol/PWMVictorSPX.h>

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES

/**
 *
 *
 * @author ExampleAuthor
 */
class Claw: public frc2::SubsystemBase {
private:
    // It's desirable that everything possible is private except
    // for methods that implement subsystem capabilities
    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
frc::DigitalInput m_limitswitch{4};
frc::PWMVictorSPX m_motor{4};

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
public:
Claw();

    void Periodic() override;
    void SimulationPeriodic() override;
    void Open();
    void Close();
    void Stop();
    bool IsGripping();

    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS
    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS


};

除了将方法添加到类实现文件“Claw.cpp”之外，还需要将方法的声明添加到头文件“Claw.h”中。必须添加的那些声明显示在此处。

要将行为添加到爪子子系统以处理打开和关闭，您需要 define commands。