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getting-startedproject-structure

Last Updated: 3/9/2026

Project Structure

This document explains the organization of the BREAD5940 2025 FRC robot code repository.

Repository Overview

2025-Public/
├── src/main/
│   ├── java/frc/robot/          # Main robot code
│   └── deploy/                   # Files deployed to RoboRIO
├── vendordeps/                   # Third-party library dependencies
├── gradle/                       # Gradle wrapper files
├── build.gradle                  # Build configuration
├── settings.gradle               # Gradle settings
└── .wpilib/                      # WPILib configuration

Source Code Structure

Main Robot Package (src/main/java/frc/robot/)

frc/robot/
├── Main.java                     # Entry point
├── Robot.java                    # Main robot class
├── RobotContainer.java           # Robot configuration and bindings
├── Constants.java                # Global constants
├── FieldConstants.java           # Field geometry constants
├── autonomous/                   # Autonomous routines
├── commands/                     # Custom commands
├── commons/                      # Shared utilities
├── config/                       # Robot configuration system
├── constants/                    # Subsystem-specific constants
├── generated/                    # Auto-generated code (TunerConstants)
├── keyboard/                     # Numpad controller
└── subsystems/                   # Robot subsystems

Key Files

Robot.java

The main robot class that extends LoggedRobot from AdvantageKit.

Responsibilities:

  • Initialize subsystems and logging
  • Manage robot lifecycle (init, periodic methods)
  • Handle mode transitions (disabled, autonomous, teleop)
  • Load PathPlanner paths
  • Configure alliance-specific behavior

Key Methods:

  • robotInit() - One-time initialization
  • robotPeriodic() - Runs every 20ms in all modes
  • autonomousInit() - Called when entering autonomous
  • teleopInit() - Called when entering teleop
  • disabledInit() - Called when entering disabled mode

RobotContainer.java

Configures the robot’s subsystems, commands, and operator interface.

Responsibilities:

  • Instantiate all subsystems
  • Configure button bindings (driver and operator controls)
  • Set default commands
  • Provide autonomous command selection
  • Configure vision systems

Key Components:

  • Xbox controllers (driver and operator)
  • Numpad controller for level selection
  • Subsystem instances (swerve, intake, etc.)
  • Vision cameras (PhotonVision, RealSense)

Constants.java

Global constants used across the robot code.

Contains:

  • CAN IDs for motors and sensors
  • Physical measurements
  • Timeout values
  • Default speeds and accelerations

FieldConstants.java

Field-specific geometry and coordinates for the 2025 game.

Contains:

  • Reef positions
  • Coral station locations
  • Processor locations
  • Scoring zones
  • Alliance-specific coordinates

Subsystems Directory

Subsystem Organization

Each subsystem follows a consistent package structure:

subsystems/
├── Superstructure.java           # Main state machine coordinator
├── swerve/                       # Swerve drivetrain
│   ├── Swerve.java
│   └── [implementation files]
├── intake/                       # Game piece intake
│   ├── Intake.java
│   └── [implementation files]
├── endeffector/                  # Scoring mechanism
│   ├── EndEffector.java
│   └── [implementation files]
├── indexer/                      # Game piece management
│   ├── Indexer.java
│   └── [implementation files]
├── elevatorpivot/                # Vertical/angular positioning
│   ├── ElevatorPivot.java
│   └── [implementation files]
├── climber/                      # End-game climbing
│   ├── Climber.java
│   └── [implementation files]
└── vision/                       # Vision processing
    ├── PhotonAprilTagVision.java
    ├── RealSenseVision.java
    └── ObjectDetection.java

Subsystem Architecture Pattern

Each subsystem typically includes:

  1. Main Subsystem Class - Extends SubsystemBase
  2. IO Interface - Hardware abstraction layer
  3. IO Implementation(s) - Real hardware and simulation implementations
  4. Inputs Class - Logged inputs from hardware
  5. State Enum - Subsystem states (if applicable)

Commands Directory

Custom commands for autonomous and teleop operations:

commands/
├── AutoPlaceCommand.java         # Autonomous scoring
├── MoveToPoseCommand.java        # Path following to target pose
├── MoveToCoralCommand.java       # Navigate to coral
├── AutoGrabAlgaeCommand.java     # Autonomous algae pickup
├── NetScoringCommand.java        # Net scoring routine
├── ScoreProcessorCommand.java    # Processor scoring
├── ReefFacingCommand.java        # Face reef structure
├── HeadingLockCommand.java       # Lock robot heading
├── LollipopAutoCommand.java      # Lollipop autonomous pattern
└── [other commands]

Autonomous Directory

autonomous/
└── AutonomousSelector.java       # Auto routine selection

Autonomous paths are stored as PathPlanner JSON files in src/main/deploy/pathplanner/paths/.

Configuration System

BreadConfig

The config/ directory contains the robot configuration system:

config/
└── BreadConfig.java              # Robot-specific settings

Purpose:

  • Support multiple robot configurations (competition, practice, beta)
  • Define hardware IDs and constants per robot
  • Enable easy switching between robot configurations

Commons Directory

Shared utilities and helper classes:

commons/
├── AllianceFlipUtil.java         # Alliance-aware coordinate flipping
├── BreadUtil.java                # General utilities
├── LoggedTunableNumber.java      # Live-tunable values
├── ScoringOffsets.java           # Scoring position adjustments
└── [other utilities]

Generated Code

generated/
└── TunerConstants.java           # CTRE Tuner X generated swerve config

Note: This file is auto-generated by CTRE Phoenix Tuner X. Do not edit manually.

Deploy Directory

src/main/deploy/
└── pathplanner/                  # PathPlanner configuration
    ├── paths/                    # Autonomous path files
    └── autos/                    # Autonomous routine definitions

Files in this directory are deployed to the RoboRIO at /home/lvuser/deploy/.

Build Configuration

build.gradle

Key Settings:

  • Java 17 compatibility
  • WPILib version: 2025.3.2
  • Team number: Loaded from .wpilib/wpilib_preferences.json
  • Dependencies: WPILib, vendor libraries, Jama matrix library
  • Simulation support enabled

vendordeps/

Third-party library JSON descriptors:

  • CTRE Phoenix 6
  • PathPlanner
  • PhotonVision
  • AdvantageKit
  • Other vendor dependencies

Logging and Telemetry

The project uses AdvantageKit for comprehensive logging:

  • Logs stored on USB drive at /U/logs/ on RoboRIO
  • NetworkTables publishing for live dashboard data
  • Replay-compatible log format for simulation

Code Organization Best Practices

Package Naming

  • All code under frc.robot package
  • Subsystems in frc.robot.subsystems
  • Commands in frc.robot.commands
  • Utilities in frc.robot.commons

File Naming Conventions

  • Subsystems: [SubsystemName].java
  • Commands: [Action][Subsystem]Command.java
  • Constants: End with Constants.java
  • IO interfaces: [Subsystem]IO.java
  • IO implementations: [Subsystem]IO[Type].java

State Management

  • Subsystems use enum-based state machines
  • Superstructure coordinates multi-subsystem states
  • State transitions logged via AdvantageKit

Next Steps

setup-guidedevelopment-environment