RobotMerge

Primary FRC robot codebase for Early College High School / Hangar 84.
Written in Kotlin using WPILib’s command-based framework, RobotMerge supports multiple drivetrain types (MAXSwerve and Mecanum), autonomous path following, rich telemetry, and a custom-built simulation environment.

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Overview

RobotMerge is the team’s main robot software project, designed to unify drivetrain experimentation, autonomous development, telemetry, and simulation into a single, maintainable codebase.

A hardware boot selector or simulation chooser determines whether the robot runs as a Swerve or Mecanum drive system, allowing shared commands, controls, and autonomous logic across both implementations.

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Key Features

• Kotlin + WPILib command-based architecture
• Runtime selection between MAXSwerve and Mecanum drivetrains
• Autonomous routines using PathPlanner and AutoBuilder
• Real-time telemetry via SmartDashboard / NetworkTables
• Custom simulation framework with:
  • ground-truth vs estimated pose comparison
  • sensor noise and bias modeling
  • configurable start poses
• Field visualization using Field2d
• Modular drivetrain, command, and telemetry abstractions

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Drivetrain Selection

Real Robot

• A digital input (DIO 19) selects the drivetrain at boot:
  • LOW → SWERVE
  • HIGH → MECANUM

Simulation

• A SmartDashboard chooser (Sim/RobotType) selects the drivetrain type at runtime.

This allows testing both drivebases without changing code.

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Controls (Xbox Controller – Port 0)

Driving

• Swerve Mode
  • Left Stick Y → forward/back
  • Left Stick X → strafe
  • Right Stick X → rotation
  • Left Bumper (hold) → park / lock wheels
• Mecanum Mode
  • Left Stick X → strafe
  • Left Stick Y → forward/back
  • Right Stick X → rotation

Inputs use:

• deadband (0.08)
• squared response curves
• slew-rate limiting for smooth control

Launcher

• Left Trigger (hold) → intake
• Right Trigger (hold) → launch
• Release → stop

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Autonomous

Autonomous routines are built using PathPlanner and executed via WPILib’s AutoBuilder:

• Path-based autonomous commands
• Alliance-aware path flipping
• Odometry-based starting pose alignment
• Unified autonomous interface for both drivetrains

An autonomous chooser is published to SmartDashboard and populated by the active drivetrain implementation.

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Telemetry & Monitoring

Runtime Telemetry

Published continuously via NetworkTables / SmartDashboard:

• Robot pose:
  • X, Y, HeadingDeg
• Gyro:
  • YawDeg, YawRateDegPerSec
• Chassis speeds:
  • Vx, Vy, Omega
• Wheel/module encoder positions and velocities (FL / FR / RL / RR)
• Driver Station state:
  • Enabled / Auto / Teleop
  • Match time

Telemetry is designed for live debugging, tuning, and validation.

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Simulation Framework

RobotMerge includes a custom simulation system, not just default WPILib sim.

Simulation Capabilities

• Deterministic simulation clock (SimClock)
• Ground-truth robot pose tracking
• Estimated pose tracking (odometry)
• Realistic sensor modeling:
  • gyro noise
  • gyro rate noise
  • bias drift over time
• Truth vs measured comparison telemetry
• Configurable drivetrain selection in sim
• Field visualization via Field2d

Pose Comparison Telemetry

The following simulation-only telemetry is published:

• True pose vs estimated pose
• Pose error:
  • ΔX
  • ΔY
  • ΔYaw
  • XY distance error
  • Angular error
• True vs measured gyro yaw and yaw rate

This allows direct validation of odometry, estimation accuracy, and autonomous behavior before deploying to hardware.

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Simulation Start Poses

Predefined field start poses are available for both alliances:

• Left / Middle / Right (Red)
• Left / Middle / Right (Blue)

Each pose:

• resets odometry
• zeros the gyro
• sets ground-truth and estimated pose
• updates the Field2d display

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Repository Structure

src/
├── main/
│   ├──deploy/
│   |   ├── pathplanner/
│   |   |    ├── autos/           # Autonomous routines
│   |   |    ├── paths/           # PathPlanner path files
│   |   |    ├── navgrid.json     # Navigation grid
│   |   |
|   |   └── telemetry/
|   |            └── telemetry.json # Telemetry configuration
│   └── kotlin/
│       └── org/hangar84/robot2026/
│           ├── commands/        # Reusable drive and robot commands
│           ├── constants/       # Robot constants and configuration values
│           ├── io/              # Robot hardware interfaces
│           │    ├── real/       # Actual robot hardware
│           │    └── sim/        # Simulated robot hardware
│           ├── mecanum/         # Mecanum drivetrain implementation
│           ├── sim/             # Custom simulation framework (state, sensors, field)
│           ├── subsystems/      # Shared subsystem interfaces and implementations
│           ├── swerve/          # MAXSwerve drivetrain implementation
│           ├── telemetry/       # Telemetry and simulation telemetry helpers
│           ├── Main.kt          # Robot entry point
│           ├── Robot.kt         # Robot lifecycle logic
│           └── RobotContainer.kt# Input bindings, drivetrain selection, autos

Getting Started

1. Install WPILib for the current FRC season
2. Clone this repository
3. Open in WPILib VS Code
4. Build and deploy, or run Simulate Robot Code

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Contributing (Team Workflow)

• Branch naming:
  • feature/...
  • fix/...
• Validate behavior in simulation before merging
• Keep telemetry keys stable to avoid dashboard breakage

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Credits

Early College High School Robotics / Hangar 84
Built with WPILib, PathPlanner, and vendor libraries.