Introduction to Software

Table of contents

1. Introduction to Software
   1. AutonomousDistance
   2. Explaining the Code
   3. Try it Yourself

AutonomousDistance

The robot is controlled by code that you have cloned from the repository in the previous section. Navigate to the file called AutonomousDistance.java. The path should be XRPminibots/src/main/java/frc/robot/commands/AutonomousDistance.java.

There should be some code in the file, which should look similar to this.

package frc.robot.commands;


import frc.robot.subsystems.Drivetrain;
import edu.wpi.first.wpilibj2.command.SequentialCommandGroup;


public class AutonomousDistance extends SequentialCommandGroup {
  /**
   * Creates a new Autonomous Drive based on distance. This will drive out for a specified distance,
   * turn around and drive back.
   *
   * @param drivetrain The drivetrain subsystem on which this command will run
   */
  public AutonomousDistance(Drivetrain drivetrain) {
    addCommands(
        new DriveDistance(1, 20, drivetrain),
        new TurnDegrees(-1, 90, drivetrain),
        new DriveDistance(2, 15, drivetrain),
        new TurnDegrees(5, 45, drivetrain),
        new DriveDistance(1, 10, drivetrain)
    );
  }
}

Explaining the Code

The AutonomousDistance class inherits from SequentialCommandGroup because it extends that class. The SequentialCommandGroup executes commands in a specific sequence. Inside the AutonomousDistance class, a constructor is defined that takes a Drivetrain parameter, which controls the robot’s movement. Within the constructor, the addCommands() method is used to add multiple commands in a sequence.

A method is a block of code that performs certain actions when called. In this case, the addCommands() method includes several commands that instruct the Drivetrain to carry out actions in a particular order. The commands will be run in the order they are passed into addCommands(). For example, the code first tells the robot to drive a specific distance at a certain velocity, then it commands the robot to turn a set number of degrees with a certain speed, and so on. Each command in the sequence is executed one after the other, guiding the robot through a series of movements.

Try it Yourself

Now, try to Simulate the Robot Code, and select the Autonomous mode.

What happens?

The XRP Minibot should move around on its own, driving forward and turning.

Feel free to play around with the code and the code inside the parenthesis, or arguments, of addCommands(). What changes?