Package frc.robot

Class LimelightHelpers

java.lang.Object
frc.robot.LimelightHelpers
public class LimelightHelpers extends Object
LimelightHelpers provides static methods and classes for interfacing with Limelight vision cameras in FRC. This library supports all Limelight features including AprilTag tracking, Neural Networks, and standard color/retroreflective tracking.

  • Constructor Details

    • LimelightHelpers

      public LimelightHelpers()

  • Method Details

    • toPose3D

      public static Pose3d toPose3D(double[] inData)
      Takes a 6-length array of pose data and converts it to a Pose3d object. Array format: [x, y, z, roll, pitch, yaw] where angles are in degrees.
      Parameters:
      inData - Array containing pose data [x, y, z, roll, pitch, yaw]
      Returns:
      Pose3d object representing the pose, or empty Pose3d if invalid data

    • toPose2D

      public static Pose2d toPose2D(double[] inData)
      Takes a 6-length array of pose data and converts it to a Pose2d object. Uses only x, y, and yaw components, ignoring z, roll, and pitch. Array format: [x, y, z, roll, pitch, yaw] where angles are in degrees.
      Parameters:
      inData - Array containing pose data [x, y, z, roll, pitch, yaw]
      Returns:
      Pose2d object representing the pose, or empty Pose2d if invalid data

    • pose3dToArray

      public static double[] pose3dToArray(Pose3d pose)
      Converts a Pose3d object to an array of doubles in the format [x, y, z, roll, pitch, yaw]. Translation components are in meters, rotation components are in degrees.
      Parameters:
      pose - The Pose3d object to convert
      Returns:
      A 6-element array containing [x, y, z, roll, pitch, yaw]

    • pose2dToArray

      public static double[] pose2dToArray(Pose2d pose)
      Converts a Pose2d object to an array of doubles in the format [x, y, z, roll, pitch, yaw]. Translation components are in meters, rotation components are in degrees. Note: z, roll, and pitch will be 0 since Pose2d only contains x, y, and yaw.
      Parameters:
      pose - The Pose2d object to convert
      Returns:
      A 6-element array containing [x, y, 0, 0, 0, yaw]

    • getRawFiducials

      public static LimelightHelpers.RawFiducial[] getRawFiducials(String limelightName)
      Gets the latest raw fiducial/AprilTag detection results from NetworkTables.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Array of RawFiducial objects containing detection details

    • getRawDetections

      public static LimelightHelpers.RawDetection[] getRawDetections(String limelightName)
      Gets the latest raw neural detector results from NetworkTables
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Array of RawDetection objects containing detection details

    • printPoseEstimate

      public static void printPoseEstimate(LimelightHelpers.PoseEstimate pose)
      Prints detailed information about a PoseEstimate to standard output. Includes timestamp, latency, tag count, tag span, average tag distance, average tag area, and detailed information about each detected fiducial.
      Parameters:
      pose - The PoseEstimate object to print. If null, prints "No PoseEstimate available."

    • validPoseEstimate

      public static Boolean validPoseEstimate(LimelightHelpers.PoseEstimate pose)

    • getLimelightNTTable

      public static NetworkTable getLimelightNTTable(String tableName)

    • Flush

      public static void Flush()

    • getLimelightNTTableEntry

      public static NetworkTableEntry getLimelightNTTableEntry(String tableName, String entryName)

    • getLimelightDoubleArrayEntry

      public static DoubleArrayEntry getLimelightDoubleArrayEntry(String tableName, String entryName)

    • getLimelightNTDouble

      public static double getLimelightNTDouble(String tableName, String entryName)

    • setLimelightNTDouble

      public static void setLimelightNTDouble(String tableName, String entryName, double val)

    • setLimelightNTDoubleArray

      public static void setLimelightNTDoubleArray(String tableName, String entryName, double[] val)

    • getLimelightNTDoubleArray

      public static double[] getLimelightNTDoubleArray(String tableName, String entryName)

    • getLimelightNTString

      public static String getLimelightNTString(String tableName, String entryName)

    • getLimelightNTStringArray

      public static String[] getLimelightNTStringArray(String tableName, String entryName)

    • getLimelightURLString

      public static URL getLimelightURLString(String tableName, String request)

    • getTV

      public static boolean getTV(String limelightName)
      Does the Limelight have a valid target?
      Parameters:
      limelightName - Name of the Limelight camera ("" for default)
      Returns:
      True if a valid target is present, false otherwise

    • getTX

      public static double getTX(String limelightName)
      Gets the horizontal offset from the crosshair to the target in degrees.
      Parameters:
      limelightName - Name of the Limelight camera ("" for default)
      Returns:
      Horizontal offset angle in degrees

    • getTY

      public static double getTY(String limelightName)
      Gets the vertical offset from the crosshair to the target in degrees.
      Parameters:
      limelightName - Name of the Limelight camera ("" for default)
      Returns:
      Vertical offset angle in degrees

    • getTXNC

      public static double getTXNC(String limelightName)
      Gets the horizontal offset from the principal pixel/point to the target in degrees. This is the most accurate 2d metric if you are using a calibrated camera and you don't need adjustable crosshair functionality.
      Parameters:
      limelightName - Name of the Limelight camera ("" for default)
      Returns:
      Horizontal offset angle in degrees

    • getTYNC

      public static double getTYNC(String limelightName)
      Gets the vertical offset from the principal pixel/point to the target in degrees. This is the most accurate 2d metric if you are using a calibrated camera and you don't need adjustable crosshair functionality.
      Parameters:
      limelightName - Name of the Limelight camera ("" for default)
      Returns:
      Vertical offset angle in degrees

    • getTA

      public static double getTA(String limelightName)
      Gets the target area as a percentage of the image (0-100%).
      Parameters:
      limelightName - Name of the Limelight camera ("" for default)
      Returns:
      Target area percentage (0-100)

    • getT2DArray

      public static double[] getT2DArray(String limelightName)
      T2D is an array that contains several targeting metrcis
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Array containing [targetValid, targetCount, targetLatency, captureLatency, tx, ty, txnc, tync, ta, tid, targetClassIndexDetector, targetClassIndexClassifier, targetLongSidePixels, targetShortSidePixels, targetHorizontalExtentPixels, targetVerticalExtentPixels, targetSkewDegrees]

    • getTargetCount

      public static int getTargetCount(String limelightName)
      Gets the number of targets currently detected.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Number of detected targets

    • getClassifierClassIndex

      public static int getClassifierClassIndex(String limelightName)
      Gets the classifier class index from the currently running neural classifier pipeline
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Class index from classifier pipeline

    • getDetectorClassIndex

      public static int getDetectorClassIndex(String limelightName)
      Gets the detector class index from the primary result of the currently running neural detector pipeline.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Class index from detector pipeline

    • getClassifierClass

      public static String getClassifierClass(String limelightName)
      Gets the current neural classifier result class name.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Class name string from classifier pipeline

    • getDetectorClass

      public static String getDetectorClass(String limelightName)
      Gets the primary neural detector result class name.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Class name string from detector pipeline

    • getLatency_Pipeline

      public static double getLatency_Pipeline(String limelightName)
      Gets the pipeline's processing latency contribution.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Pipeline latency in milliseconds

    • getLatency_Capture

      public static double getLatency_Capture(String limelightName)
      Gets the capture latency.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Capture latency in milliseconds

    • getCurrentPipelineIndex

      public static double getCurrentPipelineIndex(String limelightName)
      Gets the active pipeline index.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Current pipeline index (0-9)

    • getCurrentPipelineType

      public static String getCurrentPipelineType(String limelightName)
      Gets the current pipeline type.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      Pipeline type string (e.g. "retro", "apriltag", etc)

    • getJSONDump

      public static String getJSONDump(String limelightName)
      Gets the full JSON results dump.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      JSON string containing all current results

    • getBotpose

      @Deprecated public static double[] getBotpose(String limelightName)
      Deprecated.
      Switch to getBotPose
      Parameters:
      limelightName -
      Returns:

    • getBotpose_wpiRed

      @Deprecated public static double[] getBotpose_wpiRed(String limelightName)
      Deprecated.
      Switch to getBotPose_wpiRed
      Parameters:
      limelightName -
      Returns:

    • getBotpose_wpiBlue

      @Deprecated public static double[] getBotpose_wpiBlue(String limelightName)
      Deprecated.
      Switch to getBotPose_wpiBlue
      Parameters:
      limelightName -
      Returns:

    • getBotPose

      public static double[] getBotPose(String limelightName)

    • getBotPose_wpiRed

      public static double[] getBotPose_wpiRed(String limelightName)

    • getBotPose_wpiBlue

      public static double[] getBotPose_wpiBlue(String limelightName)

    • getBotPose_TargetSpace

      public static double[] getBotPose_TargetSpace(String limelightName)

    • getCameraPose_TargetSpace

      public static double[] getCameraPose_TargetSpace(String limelightName)

    • getTargetPose_CameraSpace

      public static double[] getTargetPose_CameraSpace(String limelightName)

    • getTargetPose_RobotSpace

      public static double[] getTargetPose_RobotSpace(String limelightName)

    • getTargetColor

      public static double[] getTargetColor(String limelightName)

    • getFiducialID

      public static double getFiducialID(String limelightName)

    • getNeuralClassID

      public static String getNeuralClassID(String limelightName)

    • getRawBarcodeData

      public static String[] getRawBarcodeData(String limelightName)

    • getBotPose3d

      public static Pose3d getBotPose3d(String limelightName)

    • getBotPose3d_wpiRed

      public static Pose3d getBotPose3d_wpiRed(String limelightName)
      (Not Recommended) Gets the robot's 3D pose in the WPILib Red Alliance Coordinate System.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the robot's position and orientation in Red Alliance field space

    • getBotPose3d_wpiBlue

      public static Pose3d getBotPose3d_wpiBlue(String limelightName)
      (Recommended) Gets the robot's 3D pose in the WPILib Blue Alliance Coordinate System.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the robot's position and orientation in Blue Alliance field space

    • getBotPose3d_TargetSpace

      public static Pose3d getBotPose3d_TargetSpace(String limelightName)
      Gets the robot's 3D pose with respect to the currently tracked target's coordinate system.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the robot's position and orientation relative to the target

    • getCameraPose3d_TargetSpace

      public static Pose3d getCameraPose3d_TargetSpace(String limelightName)
      Gets the camera's 3D pose with respect to the currently tracked target's coordinate system.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the camera's position and orientation relative to the target

    • getTargetPose3d_CameraSpace

      public static Pose3d getTargetPose3d_CameraSpace(String limelightName)
      Gets the target's 3D pose with respect to the camera's coordinate system.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the target's position and orientation relative to the camera

    • getTargetPose3d_RobotSpace

      public static Pose3d getTargetPose3d_RobotSpace(String limelightName)
      Gets the target's 3D pose with respect to the robot's coordinate system.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the target's position and orientation relative to the robot

    • getCameraPose3d_RobotSpace

      public static Pose3d getCameraPose3d_RobotSpace(String limelightName)
      Gets the camera's 3D pose with respect to the robot's coordinate system.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      Pose3d object representing the camera's position and orientation relative to the robot

    • getBotPose2d_wpiBlue

      public static Pose2d getBotPose2d_wpiBlue(String limelightName)
      Gets the Pose2d for easy use with Odometry vision pose estimator (addVisionMeasurement)
      Parameters:
      limelightName -
      Returns:

    • getBotPoseEstimate_wpiBlue

      public static LimelightHelpers.PoseEstimate getBotPoseEstimate_wpiBlue(String limelightName)
      Gets the MegaTag1 Pose2d and timestamp for use with WPILib pose estimator (addVisionMeasurement) in the WPILib Blue alliance coordinate system.
      Parameters:
      limelightName -
      Returns:

    • getBotPoseEstimate_wpiBlue_MegaTag2

      public static LimelightHelpers.PoseEstimate getBotPoseEstimate_wpiBlue_MegaTag2(String limelightName)
      Gets the MegaTag2 Pose2d and timestamp for use with WPILib pose estimator (addVisionMeasurement) in the WPILib Blue alliance coordinate system. Make sure you are calling setRobotOrientation() before calling this method.
      Parameters:
      limelightName -
      Returns:

    • getBotPose2d_wpiRed

      public static Pose2d getBotPose2d_wpiRed(String limelightName)
      Gets the Pose2d for easy use with Odometry vision pose estimator (addVisionMeasurement)
      Parameters:
      limelightName -
      Returns:

    • getBotPoseEstimate_wpiRed

      public static LimelightHelpers.PoseEstimate getBotPoseEstimate_wpiRed(String limelightName)
      Gets the Pose2d and timestamp for use with WPILib pose estimator (addVisionMeasurement) when you are on the RED alliance
      Parameters:
      limelightName -
      Returns:

    • getBotPoseEstimate_wpiRed_MegaTag2

      public static LimelightHelpers.PoseEstimate getBotPoseEstimate_wpiRed_MegaTag2(String limelightName)
      Gets the Pose2d and timestamp for use with WPILib pose estimator (addVisionMeasurement) when you are on the RED alliance
      Parameters:
      limelightName -
      Returns:

    • getBotPose2d

      public static Pose2d getBotPose2d(String limelightName)
      Gets the Pose2d for easy use with Odometry vision pose estimator (addVisionMeasurement)
      Parameters:
      limelightName -
      Returns:

    • getIMUData

      public static LimelightHelpers.IMUData getIMUData(String limelightName)
      Gets the current IMU data from NetworkTables. IMU data is formatted as [robotYaw, Roll, Pitch, Yaw, gyroX, gyroY, gyroZ, accelX, accelY, accelZ]. Returns all zeros if data is invalid or unavailable.
      Parameters:
      limelightName - Name/identifier of the Limelight
      Returns:
      IMUData object containing all current IMU data

    • setPipelineIndex

      public static void setPipelineIndex(String limelightName, int pipelineIndex)

    • setPriorityTagID

      public static void setPriorityTagID(String limelightName, int ID)

    • setLEDMode_PipelineControl

      public static void setLEDMode_PipelineControl(String limelightName)
      Sets LED mode to be controlled by the current pipeline.
      Parameters:
      limelightName - Name of the Limelight camera

    • setLEDMode_ForceOff

      public static void setLEDMode_ForceOff(String limelightName)

    • setLEDMode_ForceBlink

      public static void setLEDMode_ForceBlink(String limelightName)

    • setLEDMode_ForceOn

      public static void setLEDMode_ForceOn(String limelightName)

    • setStreamMode_Standard

      public static void setStreamMode_Standard(String limelightName)
      Enables standard side-by-side stream mode.
      Parameters:
      limelightName - Name of the Limelight camera

    • setStreamMode_PiPMain

      public static void setStreamMode_PiPMain(String limelightName)
      Enables Picture-in-Picture mode with secondary stream in the corner.
      Parameters:
      limelightName - Name of the Limelight camera

    • setStreamMode_PiPSecondary

      public static void setStreamMode_PiPSecondary(String limelightName)
      Enables Picture-in-Picture mode with primary stream in the corner.
      Parameters:
      limelightName - Name of the Limelight camera

    • setCropWindow

      public static void setCropWindow(String limelightName, double cropXMin, double cropXMax, double cropYMin, double cropYMax)
      Sets the crop window for the camera. The crop window in the UI must be completely open.
      Parameters:
      limelightName - Name of the Limelight camera
      cropXMin - Minimum X value (-1 to 1)
      cropXMax - Maximum X value (-1 to 1)
      cropYMin - Minimum Y value (-1 to 1)
      cropYMax - Maximum Y value (-1 to 1)

    • setFiducial3DOffset

      public static void setFiducial3DOffset(String limelightName, double offsetX, double offsetY, double offsetZ)
      Sets 3D offset point for easy 3D targeting.

    • SetRobotOrientation

      public static void SetRobotOrientation(String limelightName, double yaw, double yawRate, double pitch, double pitchRate, double roll, double rollRate)
      Sets robot orientation values used by MegaTag2 localization algorithm.
      Parameters:
      limelightName - Name/identifier of the Limelight
      yaw - Robot yaw in degrees. 0 = robot facing red alliance wall in FRC
      yawRate - (Unnecessary) Angular velocity of robot yaw in degrees per second
      pitch - (Unnecessary) Robot pitch in degrees
      pitchRate - (Unnecessary) Angular velocity of robot pitch in degrees per second
      roll - (Unnecessary) Robot roll in degrees
      rollRate - (Unnecessary) Angular velocity of robot roll in degrees per second

    • SetRobotOrientation_NoFlush

      public static void SetRobotOrientation_NoFlush(String limelightName, double yaw, double yawRate, double pitch, double pitchRate, double roll, double rollRate)

    • SetIMUMode

      public static void SetIMUMode(String limelightName, int mode)
      Configures the IMU mode for MegaTag2 Localization
      Parameters:
      limelightName - Name/identifier of the Limelight
      mode - IMU mode.

    • SetFidcuial3DOffset

      public static void SetFidcuial3DOffset(String limelightName, double x, double y, double z)
      Sets the 3D point-of-interest offset for the current fiducial pipeline. https://docs.limelightvision.io/docs/docs-limelight/pipeline-apriltag/apriltag-3d#point-of-interest-tracking
      Parameters:
      limelightName - Name/identifier of the Limelight
      x - X offset in meters
      y - Y offset in meters
      z - Z offset in meters

    • SetFiducialIDFiltersOverride

      public static void SetFiducialIDFiltersOverride(String limelightName, int[] validIDs)
      Overrides the valid AprilTag IDs that will be used for localization. Tags not in this list will be ignored for robot pose estimation.
      Parameters:
      limelightName - Name/identifier of the Limelight
      validIDs - Array of valid AprilTag IDs to track

    • SetFiducialDownscalingOverride

      public static void SetFiducialDownscalingOverride(String limelightName, float downscale)
      Sets the downscaling factor for AprilTag detection. Increasing downscale can improve performance at the cost of potentially reduced detection range.
      Parameters:
      limelightName - Name/identifier of the Limelight
      downscale - Downscale factor. Valid values: 1.0 (no downscale), 1.5, 2.0, 3.0, 4.0. Set to 0 for pipeline control.

    • setCameraPose_RobotSpace

      public static void setCameraPose_RobotSpace(String limelightName, double forward, double side, double up, double roll, double pitch, double yaw)
      Sets the camera pose relative to the robot.
      Parameters:
      limelightName - Name of the Limelight camera
      forward - Forward offset in meters
      side - Side offset in meters
      up - Up offset in meters
      roll - Roll angle in degrees
      pitch - Pitch angle in degrees
      yaw - Yaw angle in degrees

    • setPythonScriptData

      public static void setPythonScriptData(String limelightName, double[] outgoingPythonData)

    • getPythonScriptData

      public static double[] getPythonScriptData(String limelightName)

    • takeSnapshot

      public static CompletableFuture<Boolean> takeSnapshot(String tableName, String snapshotName)
      Asynchronously take snapshot.

    • getLatestResults

      public static LimelightHelpers.LimelightResults getLatestResults(String limelightName)
      Gets the latest JSON results output and returns a LimelightResults object.
      Parameters:
      limelightName - Name of the Limelight camera
      Returns:
      LimelightResults object containing all current target data