Chief Delphi - Java help

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I am part of team 4592 and I took on the task of being programming captain. I don't know much and i need some help. I need to run a motor while a button is being pressed and held. I've gone through wpilib and can't figure it out. Thanks to anyone who can help it is greatly appreciated.

WPILib resources:
Screensteps
API Reference (Java)
API Reference (C++)

Using the command based architecture, you need to first create a subsystem that the motor belongs to

Code:

public class MyMotorSubsystem extends Subsystem {

  CANSomething myMotor;

  public MyMotorSubsystem {

    myMotor = new CANSomething(RobotMap.CAN_ID_MY_MOTOR);

  }

  public void setMotor(double value) {

    myMotor.set(value);

  }

}

Then you need a command to run the motor.

Code:

public class CommandBase extends Command {

  public static MyMotorSubsystem myMotorSubsystem;

  public static void init() {

    myMotorSubsystem = new MyMotorSubsystem();

  }

}



public class RunMotorCommand extends CommandBase {

  JoystickButton runMotorButton;

  public RunMotorCommand(JoystickButton runMotorButton) {

    this.runMotorButton = runMotorButton;

    runMotorButton.whenPressed(this);

  }

  void initialize() {

    requires(myMotorSubsystem);

  }

  void run() {

    myMotorSubsystem->setMotor(1.0);

  }

  void isFinished() {

    return runMotorButton.get();

  }

  void end() {

    myMotorSubsystem->setMotor(0.0);

  }

  void interrupted() {

    myMotorSubsystem->setMotor(0.0);

  }

}

Then you need to create an instance of the command

Code:

// somewhere in OI.java

new RunMotorCommand(new JoystickButton(myJoystick, something));

Here is what the above would look like in Java:

Code:

public class MyMotorSubsystem extends Subsystem {

  ControllerType myMotor;

  public MyMotorSubsystem () {

    myMotor = new ControllerType(RobotMap.ID_MY_MOTOR);

  }

  public void setMotor(double value) {

    myMotor.set(value);

  }

}

Command to run the motor.

Code:

public class CommandBase extends Command {

  public static MyMotorSubsystem myMotorSubsystem;

  public static void init() {

    myMotorSubsystem = new MyMotorSubsystem();

  }

}



public class RunMotorCommand extends CommandBase {

  JoystickButton runMotorButton;

  public RunMotorCommand(JoystickButton runMotorButton) {

    this.runMotorButton = runMotorButton;

    runMotorButton.whenPressed(this);

  }

  void initialize() {

    requires(myMotorSubsystem);

  }

  void execute() {

    myMotorSubsystem.setMotor(1.0);

  }

  boolean isFinished() {

    return !runMotorButton.get();

  }

  void end() {

    myMotorSubsystem.setMotor(0.0);

  }

  void interrupted() {

    myMotorSubsystem.setMotor(0.0);

  }

}

Create an instance of the command

Code:

// somewhere in OI.java

new RunMotorCommand(new JoystickButton(myJoystick, something));

My team does not use the CommandBase, and we usually instantiate subsystems in the Robot.java file, so I am not 100% sure this is right, but the basic idea should be apparent. Basically, create a command that in the execute will call a method from a subsystem that sets the motor to the value you want, which is triggered by a button and will end when that button isn't pressed.

2016 was our first year with Java too, and being the sole programmer, I kinda got thrown into the fire. Here's our code from 2016. Its mostly very simple command-based stuff, but if you have any questions you can PM me. Hope that helps!