Skip to main content

Documentation Index

Fetch the complete documentation index at: https://mintlify.com/spectrum3847/2026-Spectrum/llms.txt

Use this file to discover all available pages before exploring further.

This page covers everything specific to Spectrum 3847’s 2026 FRC season competing in the game REBUILT. It documents the robot’s operational states, driver and operator control bindings, vision hardware configuration, and the development workflow adopted for this season.

​
Robot states for REBUILT

The State enum (in frc.robot.State) defines the high-level operational modes the robot can be in. Coordinator.java fans each state out to the appropriate subsystem commands simultaneously.
StateDescription
IDLEAll mechanisms in neutral/home position. Default when no action is active.
INTAKE_FUELGround intake active — intake extended, bed and tower running, launcher idling. Triggered by pilot RT (when LT not held).
SNAKE_INTAKEAlternate intake mode.
TRACK_TARGETChassis rotates toward the goal via pilotAimAtTarget; launcher spins up via ShotCalculator. Pilot X button (whileTrue).
TRACK_TARGET_WITH_NO_SWERVELauncher tracks target speed but swerve does not auto-rotate. Used in autonomous shot prep.
LAUNCH_WITH_SQUEEZEFire sequence — pilot LT (without RT). Advances fuel once aimingAtTarget() is true.
LAUNCH_WITH_SQUEEZE_WITH_NO_DELAYImmediate fire with no delay, triggered on RT release when LT is held.
LAUNCH_WITHOUT_SQUEEZEFire sequence triggered by simultaneous LT+RT press.
AUTON_TRACK_TARGETAutonomous version of target tracking (bound to Auton.autonShotPrep event trigger).
AUTON_LAUNCH_WITH_SQUEEZEAutonomous launch (bound to Auton.autonShoot event trigger).
CUSTOM_SPEED_TURRET_LAUNCHLaunches at a custom live-tunable velocity. Pilot start button (whileTrue).
UNJAMRecovery — clears jammed game pieces. Pilot A button (whileTrue).
FORCE_HOMEForces all mechanisms to home position. Pilot home+fn button combo.
COASTMotors set to coast mode (free-spinning).
BRAKEMotors set to brake mode (actively resist movement when idle).
TEST_INFINITE_LAUNCHContinuously launches fuel for calibration. Operator testX button.
TEST_IDLENeutral test state for exercising individual subsystems.

​
Driver controls layout

​
Pilot (driver) — left gamepad

The pilot controls robot movement and initiates the primary game actions.
InputAction
Left StickField-relative translation (strafe + forward/back)
Right StickRotation
RT (Right Trigger, press)INTAKE_FUEL (when LT not held)
LT (Left Trigger, press)LAUNCH_WITH_SQUEEZE (when RT not held)
LT + RT (simultaneously)LAUNCH_WITHOUT_SQUEEZE
RT release (while LT held)LAUNCH_WITH_SQUEEZE_WITH_NO_DELAY
LT release (while RT held)INTAKE_FUEL
LT or RT release (both released)IDLE
X button (whileTrue)TRACK_TARGET — chassis aims at goal, flywheel spins up
Start button (whileTrue)CUSTOM_SPEED_TURRET_LAUNCH
A button (whileTrue)UNJAM
Home + Fn comboFORCE_HOME
Home buttonClear state to IDLE

​
Operator — right gamepad

The operator stages the robot’s next action and manages mechanism handoffs.
InputAction
LB (held)Enter game-piece scoring/manipulation mode
LB + D-pad Left/RightSelect scoring location or orientation
LB + A/B/X/YSelect scoring level or handling sub-mode
LB releaseReturn to home state
Designated buttonInitiate climb sequence
Designated buttonMechanisms home/retract

​
Auto-score flow

The pilot and operator coordinate for autonomous-assisted scoring:
1

Operator stages the action

Operator holds LB and selects target using D-pad or face buttons. The robot begins positioning.
2

Pilot presses action button (RB)

Robot moves to action-ready position, aligns to the nearest AprilTag goal, and puts manipulators in prep position.
3

Pilot releases action button

The robot autonomously selects optimal scoring parameters (front/back based on pose/angle) and executes the score. No driver aim required.

​
Field zone triggers

RobotStates.java defines three field-position triggers used for conditional logic and autonomous behavior:
java
// From RobotStates.java
public static final Trigger robotInNeutralZone   = swerve.inNeutralZone();
public static final Trigger robotInEnemyZone     = swerve.inEnemyAllianceZone();
public static final Trigger robotInFeedZone      = robotInEnemyZone.or(robotInNeutralZone);
public static final Trigger robotInScoreZone     = robotInFeedZone.not();
public static final Trigger launcherOnTarget     = LauncherStates.aimingAtTarget();
These triggers can be combined with any pilot/operator trigger to create conditional behaviors (e.g., only allow launching when robotInScoreZone is true).

​
Vision hardware for REBUILT

HardwareRole
Limelight 4 (×1–2)Primary AprilTag localization via MegaTag2 pose estimates
Limelight 3 (×0–1)Secondary vision tasks
Orange Pi + PhotonVisionGame-piece (fuel) object detection
QuestNavPlanned for advanced pose estimation / logging
The AprilTag field layout used: AprilTagFields.k2026RebuiltWelded (official 2026 REBUILT welded field layout).

​
Code architecture goals for 2026

  • Sim-first: All new features developed and validated in WPILib simulation before hardware testing
  • Trigger-as-state: Replace command group nesting with Trigger-bound state transitions
  • Multi-robot: Single codebase runs on FM2026 (competition), XM2026 (experimental), PM2026 (practice), AM2026
  • Improved logging: DogLog + AdvantageScope for full data replay capability
  • CTRE 2026 swerve: Full Phoenix 6 swerve integration with Kraken X60 FOC motors
  • PathPlanner: Autonomous routines with event markers; Choreo integration explored
This codebase is under active development during the 2026 season. Expect frequent changes to states, controls, and configurations as the robot is refined for competition.

Build docs developers (and LLMs) love

Get started for freeTalk to us