Stage 1A Overview

Now, before we get into the depths of the robot code, it’s useful to look at a high-level overview of the contents of a typical WPILib project. As your code gets more advanced, you’ll see more folders and files appear, but they’re all controlled by the same basic components. Below, you can see the sample file structure you’ll be starting off with as a template for Stage 1A. If your robot has REV electronics, then the template folder’s name will be rev/ instead of ctre/

Stage 1A Template Structure

ctre/
├── src/main/
|   ├── java/first/
|   |   ├── robot/
|   |   |   ├── opmode/
|   |   |   |   ├── MyAuto.java
|   |   |   |   ├── MyTeleop.Java
|   |   |   ├── simulation/
|   |   |   |   ├── DrivetrainSim.Java
|   |   |   |   ├── SingleFlywheelSim.java
|   |   |   ├── Robot.java
|   |   ├── Main.java

You’ll notice that we’re skipping a lot of files here, because you don’t have to edit those. What’s great about about using a framework like WPILib is that it automatically generates these files when you create a new project, so you can get started coding quicker. The other folders, like src/main/deploy/ for example, will come in handy as your robot code becomes more advanced. Thus, the only files shown above are the ones directly responsible for controlling what our kitbot will do.

Note

For those who have programmed in FRC before, WPILib is currently undergoing a massive rewrite for the 2027 version, especially with regards to OpModes and Commands V3, so some files and components may be completely new!

Main.java

The first file to take note of is the Main.java file; this is the entrypoint for any Java project in real life. Its contents are pretty short and sweet (comments and package declaration removed for brevity):

import org.wpilib.framework.RobotBase;

public final class Main {
  private Main() {}

  public static void main(String... args) {
    RobotBase.startRobot(first.robot.Robot.class);
  }
}

You can see that all the Main.java file is doing is, quite literally, starting up the robot, so there’s really no reason to edit this file for now.

Note

Notice that the names of all Java files in the project are capitalized. This is a convention you should follow throughout your code.

Robot.java

But what is that one line in Main.java doing?

RobotBase.startRobot(first.robot.Robot.class);

It seems to be “starting” an instance of the first.robot.Robot class, and if we go to that class file, we end up at Robot.java. This is the core of your robot code, where:

• your subsystems are defined
• your controls are binded
• your opmodes are modified and used
• your debugging data is logged (aka telemetry).

Note

For prior FRC programmers, you might have noticed a RobotContainer.java file is missing. This file is being removed in WPILib 2027.

We’ll go through this file, as well as all of the above functionalities, more in detail later.

opmode/

For those who are used to WPILib 2026 and earlier versions, this will probably be the most significant change. In WPILib 2027 and later versions, robot frameworks are getting a new way to control the current “mode” of the robot: OpModes. We’ll talk about this a bit more in-depth later, but they essentially allow you to define various “states” for a robot during autonomous and teleop, which can then be set directly through the FIRST Driver Station. This would be useful, for example, when picking what autonomous routine to run without having to push a different version of the code for every single match. WPILib 2027 decouples many of the functions that used to be in Robot.java and moves them to separate files for autonomous and teleop periods, making it easier to differentiate what functionalities the robot has during each stage of the match.

simulation/

These are the files that control simulation of the robot, allowing you to test code without actually having a physical robot in front of you. We’ve set this up for you already; you’ll just have to set up the simulation software yourself, which we’ll cover at the end of Stage 1A.

The 2026 Kitbot

But what is all this code actually going to control? Well, the answer is the 2026 FIRST Robotics Competition kitbot, the best starting point for new FRC teams, as well as the simplest robot to get fully working. You can watch the below video to learn more about what functionalities the kitbot has. If you’re a bit confused after watching that video, don’t worry. We’ll explain the kitbot more in depth in the next section.

And that’s all you need to know to get started! The rest of Stage 1A will cover how to get from the template code to a working kitbot.

This stage will cover the following topics:

• WIP