[examples] Add simple differential drive simulation example (#2918)

This provides an example of using the differential drive simulator without needing to use the command-based library.

wpilibcExamples/src/main/cpp/examples/SimpleDifferentialDriveSimulation/cpp/Drivetrain.cpp

@@ -0,0 +1,65 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019-2020 FIRST. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "Drivetrain.h"
+
+#include <frc/RobotController.h>
+
+void Drivetrain::SetSpeeds(const frc::DifferentialDriveWheelSpeeds& speeds) {
+  auto leftFeedforward = m_feedforward.Calculate(speeds.left);
+  auto rightFeedforward = m_feedforward.Calculate(speeds.right);
+  double leftOutput = m_leftPIDController.Calculate(m_leftEncoder.GetRate(),
+                                                    speeds.left.to<double>());
+  double rightOutput = m_rightPIDController.Calculate(
+      m_rightEncoder.GetRate(), speeds.right.to<double>());
+
+  m_leftGroup.SetVoltage(units::volt_t{leftOutput} + leftFeedforward);
+  m_rightGroup.SetVoltage(units::volt_t{rightOutput} + rightFeedforward);
+}
+
+void Drivetrain::Drive(units::meters_per_second_t xSpeed,
+                       units::radians_per_second_t rot) {
+  SetSpeeds(m_kinematics.ToWheelSpeeds({xSpeed, 0_mps, rot}));
+}
+
+void Drivetrain::UpdateOdometry() {
+  m_odometry.Update(m_gyro.GetRotation2d(),
+                    units::meter_t(m_leftEncoder.GetDistance()),
+                    units::meter_t(m_rightEncoder.GetDistance()));
+}
+
+void Drivetrain::ResetOdometry(const frc::Pose2d& pose) {
+  m_leftEncoder.Reset();
+  m_rightEncoder.Reset();
+  m_drivetrainSimulator.SetPose(pose);
+  m_odometry.ResetPosition(pose, m_gyro.GetRotation2d());
+}
+
+void Drivetrain::SimulationPeriodic() {
+  // To update our simulation, we set motor voltage inputs, update the
+  // simulation, and write the simulated positions and velocities to our
+  // simulated encoder and gyro. We negate the right side so that positive
+  // voltages make the right side move forward.
+  m_drivetrainSimulator.SetInputs(units::volt_t{m_leftLeader.Get()} *
+                                      frc::RobotController::GetInputVoltage(),
+                                  units::volt_t{-m_rightLeader.Get()} *
+                                      frc::RobotController::GetInputVoltage());
+  m_drivetrainSimulator.Update(20_ms);
+
+  m_leftEncoderSim.SetDistance(
+      m_drivetrainSimulator.GetLeftPosition().to<double>());
+  m_leftEncoderSim.SetRate(
+      m_drivetrainSimulator.GetLeftVelocity().to<double>());
+  m_rightEncoderSim.SetDistance(
+      m_drivetrainSimulator.GetRightPosition().to<double>());
+  m_rightEncoderSim.SetRate(
+      m_drivetrainSimulator.GetRightVelocity().to<double>());
+  m_gyroSim.SetAngle(
+      -m_drivetrainSimulator.GetHeading().Degrees().to<double>());
+
+  m_fieldSim.SetRobotPose(m_odometry.GetPose());
+}

wpilibcExamples/src/main/cpp/examples/SimpleDifferentialDriveSimulation/cpp/Robot.cpp

@@ -0,0 +1,76 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019-2020 FIRST. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include <frc/SlewRateLimiter.h>
+#include <frc/TimedRobot.h>
+#include <frc/XboxController.h>
+#include <frc/controller/RamseteController.h>
+#include <frc/trajectory/TrajectoryGenerator.h>
+#include <frc2/Timer.h>
+
+#include "Drivetrain.h"
+
+class Robot : public frc::TimedRobot {
+ public:
+  void RobotInit() override {
+    m_trajectory = frc::TrajectoryGenerator::GenerateTrajectory(
+        frc::Pose2d(2_m, 2_m, 0_rad), {}, frc::Pose2d(6_m, 4_m, 0_rad),
+        frc::TrajectoryConfig(2_mps, 2_mps_sq));
+  }
+
+  void AutonomousInit() override {
+    m_timer.Reset();
+    m_timer.Start();
+    m_drive.ResetOdometry(m_trajectory.InitialPose());
+  }
+
+  void AutonomousPeriodic() override {
+    auto elapsed = m_timer.Get();
+    auto reference = m_trajectory.Sample(elapsed);
+    auto speeds = m_ramsete.Calculate(m_drive.GetPose(), reference);
+    m_drive.Drive(speeds.vx, speeds.omega);
+
+    m_drive.UpdateOdometry();
+  }
+
+  void TeleopPeriodic() override {
+    // Get the x speed. We are inverting this because Xbox controllers return
+    // negative values when we push forward.
+    const auto xSpeed = -m_speedLimiter.Calculate(
+                            m_controller.GetY(frc::GenericHID::kLeftHand)) *
+                        Drivetrain::kMaxSpeed;
+
+    // Get the rate of angular rotation. We are inverting this because we want a
+    // positive value when we pull to the left (remember, CCW is positive in
+    // mathematics). Xbox controllers return positive values when you pull to
+    // the right by default.
+    auto rot = -m_rotLimiter.Calculate(
+                   m_controller.GetX(frc::GenericHID::kRightHand)) *
+               Drivetrain::kMaxAngularSpeed;
+
+    m_drive.Drive(xSpeed, rot);
+  }
+
+  void SimulationPeriodic() override { m_drive.SimulationPeriodic(); }
+
+ private:
+  frc::XboxController m_controller{0};
+
+  // Slew rate limiters to make joystick inputs more gentle; 1/3 sec from 0
+  // to 1.
+  frc::SlewRateLimiter<units::scalar> m_speedLimiter{3 / 1_s};
+  frc::SlewRateLimiter<units::scalar> m_rotLimiter{3 / 1_s};
+
+  Drivetrain m_drive;
+  frc::Trajectory m_trajectory;
+  frc::RamseteController m_ramsete;
+  frc2::Timer m_timer;
+};
+
+#ifndef RUNNING_FRC_TESTS
+int main() { return frc::StartRobot<Robot>(); }
+#endif

wpilibcExamples/src/main/cpp/examples/SimpleDifferentialDriveSimulation/include/Drivetrain.h

@@ -0,0 +1,107 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019-2020 FIRST. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <frc/AnalogGyro.h>
+#include <frc/Encoder.h>
+#include <frc/PWMVictorSPX.h>
+#include <frc/SpeedControllerGroup.h>
+#include <frc/controller/PIDController.h>
+#include <frc/controller/SimpleMotorFeedforward.h>
+#include <frc/kinematics/DifferentialDriveKinematics.h>
+#include <frc/kinematics/DifferentialDriveOdometry.h>
+#include <frc/simulation/AnalogGyroSim.h>
+#include <frc/simulation/DifferentialDrivetrainSim.h>
+#include <frc/simulation/EncoderSim.h>
+#include <frc/smartdashboard/Field2d.h>
+#include <frc/smartdashboard/SmartDashboard.h>
+#include <frc/system/plant/LinearSystemId.h>
+#include <units/angle.h>
+#include <units/angular_velocity.h>
+#include <units/length.h>
+#include <units/velocity.h>
+#include <wpi/math>
+
+/**
+ * Represents a differential drive style drivetrain.
+ */
+class Drivetrain {
+ public:
+  Drivetrain() {
+    m_gyro.Reset();
+    // Set the distance per pulse for the drive encoders. We can simply use the
+    // distance traveled for one rotation of the wheel divided by the encoder
+    // resolution.
+    m_leftEncoder.SetDistancePerPulse(2 * wpi::math::pi * kWheelRadius /
+                                      kEncoderResolution);
+    m_rightEncoder.SetDistancePerPulse(2 * wpi::math::pi * kWheelRadius /
+                                       kEncoderResolution);
+
+    m_leftEncoder.Reset();
+    m_rightEncoder.Reset();
+
+    m_rightGroup.SetInverted(true);
+
+    frc::SmartDashboard::PutData("Field", &m_fieldSim);
+  }
+
+  static constexpr units::meters_per_second_t kMaxSpeed =
+      3.0_mps;  // 3 meters per second
+  static constexpr units::radians_per_second_t kMaxAngularSpeed{
+      wpi::math::pi};  // 1/2 rotation per second
+
+  void SetSpeeds(const frc::DifferentialDriveWheelSpeeds& speeds);
+  void Drive(units::meters_per_second_t xSpeed,
+             units::radians_per_second_t rot);
+  void UpdateOdometry();
+  void ResetOdometry(const frc::Pose2d& pose);
+
+  frc::Pose2d GetPose() const { return m_odometry.GetPose(); }
+
+  void SimulationPeriodic();
+
+ private:
+  static constexpr units::meter_t kTrackWidth = 0.381_m * 2;
+  static constexpr double kWheelRadius = 0.0508;  // meters
+  static constexpr int kEncoderResolution = 4096;
+
+  frc::PWMVictorSPX m_leftLeader{1};
+  frc::PWMVictorSPX m_leftFollower{2};
+  frc::PWMVictorSPX m_rightLeader{3};
+  frc::PWMVictorSPX m_rightFollower{4};
+
+  frc::SpeedControllerGroup m_leftGroup{m_leftLeader, m_leftFollower};
+  frc::SpeedControllerGroup m_rightGroup{m_rightLeader, m_rightFollower};
+
+  frc::Encoder m_leftEncoder{0, 1};
+  frc::Encoder m_rightEncoder{2, 3};
+
+  frc2::PIDController m_leftPIDController{8.5, 0.0, 0.0};
+  frc2::PIDController m_rightPIDController{8.5, 0.0, 0.0};
+
+  frc::AnalogGyro m_gyro{0};
+
+  frc::DifferentialDriveKinematics m_kinematics{kTrackWidth};
+  frc::DifferentialDriveOdometry m_odometry{m_gyro.GetRotation2d()};
+
+  // Gains are for example purposes only - must be determined for your own
+  // robot!
+  frc::SimpleMotorFeedforward<units::meters> m_feedforward{1_V, 3_V / 1_mps};
+
+  // Simulation classes help us simulate our robot
+  frc::sim::AnalogGyroSim m_gyroSim{m_gyro};
+  frc::sim::EncoderSim m_leftEncoderSim{m_leftEncoder};
+  frc::sim::EncoderSim m_rightEncoderSim{m_rightEncoder};
+  frc::Field2d m_fieldSim;
+  frc::LinearSystem<2, 2, 2> m_drivetrainSystem =
+      frc::LinearSystemId::IdentifyDrivetrainSystem(
+          1.98_V / 1_mps, 0.2_V / 1_mps_sq, 1.5_V / 1_rad_per_s,
+          0.3_V / 1_rad_per_s_sq);
+  frc::sim::DifferentialDrivetrainSim m_drivetrainSimulator{
+      m_drivetrainSystem, kTrackWidth, frc::DCMotor::CIM(2), 8, 2_in};
+};

wpilibcExamples/src/main/cpp/examples/examples.json

@@ -676,6 +676,24 @@
     "mainclass": "Main",
     "commandversion": 2
   },
+  {
+    "name": "SimpleDifferentialDriveSimulation",
+    "description": "An example of a minimal drivetrain simulation project without the command-based library.",
+    "tags": [
+      "Differential Drive",
+      "State space",
+      "Digital",
+      "Sensors",
+      "Simulation",
+      "Physics",
+      "Drivetrain",
+      "Field2d"
+    ],
+    "foldername": "SimpleDifferentialDriveSimulation",
+    "gradlebase": "cpp",
+    "mainclass": "Main",
+    "commandversion": 2
+  },
   {
     "name": "StateSpaceDriveSimulation",
     "description": "Demonstrates the use of physics simulation with a differential drivetrain and the Field2d class.",

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/examples.json

@@ -632,6 +632,23 @@
     "mainclass": "Main",
     "commandversion": 2
   },
+  {
+    "name": "SimpleDifferentialDriveSimulation",
+    "description": "An example of a minimal drivetrain simulation project without the command-based library.",
+    "tags": [
+      "Drivetrain",
+      "State space",
+      "Digital",
+      "Sensors",
+      "Actuators",
+      "Joystick",
+      "Simulation"
+    ],
+    "foldername": "simpledifferentialdrivesimulation",
+    "gradlebase": "java",
+    "mainclass": "Main",
+    "commandversion": 2
+  },
   {
     "name": "StateSpaceDriveSimulation",
     "description": "An example of drivetrain simulation in combination with a RAMSETE path following controller and the Field2d class.",

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/simpledifferentialdrivesimulation/Drivetrain.java

@@ -0,0 +1,144 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.first.wpilibj.examples.simpledifferentialdrivesimulation;
+
+import edu.wpi.first.wpilibj.AnalogGyro;
+import edu.wpi.first.wpilibj.Encoder;
+import edu.wpi.first.wpilibj.PWMVictorSPX;
+import edu.wpi.first.wpilibj.RobotController;
+import edu.wpi.first.wpilibj.SpeedControllerGroup;
+import edu.wpi.first.wpilibj.controller.PIDController;
+import edu.wpi.first.wpilibj.controller.SimpleMotorFeedforward;
+import edu.wpi.first.wpilibj.geometry.Pose2d;
+import edu.wpi.first.wpilibj.kinematics.ChassisSpeeds;
+import edu.wpi.first.wpilibj.kinematics.DifferentialDriveKinematics;
+import edu.wpi.first.wpilibj.kinematics.DifferentialDriveOdometry;
+import edu.wpi.first.wpilibj.kinematics.DifferentialDriveWheelSpeeds;
+import edu.wpi.first.wpilibj.simulation.AnalogGyroSim;
+import edu.wpi.first.wpilibj.simulation.DifferentialDrivetrainSim;
+import edu.wpi.first.wpilibj.simulation.EncoderSim;
+import edu.wpi.first.wpilibj.smartdashboard.Field2d;
+import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;
+import edu.wpi.first.wpilibj.system.LinearSystem;
+import edu.wpi.first.wpilibj.system.plant.DCMotor;
+import edu.wpi.first.wpilibj.system.plant.LinearSystemId;
+import edu.wpi.first.wpiutil.math.numbers.N2;
+
+@SuppressWarnings("PMD.TooManyFields")
+public class Drivetrain {
+  // 3 meters per second.
+  public static final double kMaxSpeed = 3.0;
+  // 1/2 rotation per second.
+  public static final double kMaxAngularSpeed = Math.PI;
+
+  private static final double kTrackWidth = 0.381 * 2;
+  private static final double kWheelRadius = 0.0508;
+  private static final int kEncoderResolution = -4096;
+
+  private final PWMVictorSPX m_leftLeader = new PWMVictorSPX(1);
+  private final PWMVictorSPX m_leftFollower = new PWMVictorSPX(2);
+  private final PWMVictorSPX m_rightLeader = new PWMVictorSPX(3);
+  private final PWMVictorSPX m_rightFollower = new PWMVictorSPX(4);
+
+  private final SpeedControllerGroup m_leftGroup
+      = new SpeedControllerGroup(m_leftLeader, m_leftFollower);
+  private final SpeedControllerGroup m_rightGroup
+      = new SpeedControllerGroup(m_rightLeader, m_rightFollower);
+
+  private final Encoder m_leftEncoder = new Encoder(0, 1);
+  private final Encoder m_rightEncoder = new Encoder(2, 3);
+
+  private final PIDController m_leftPIDController = new PIDController(8.5, 0, 0);
+  private final PIDController m_rightPIDController = new PIDController(8.5, 0, 0);
+
+  private final AnalogGyro m_gyro = new AnalogGyro(0);
+
+  private final DifferentialDriveKinematics m_kinematics
+      = new DifferentialDriveKinematics(kTrackWidth);
+  private final DifferentialDriveOdometry m_odometry
+      = new DifferentialDriveOdometry(m_gyro.getRotation2d());
+
+  // Gains are for example purposes only - must be determined for your own
+  // robot!
+  private final SimpleMotorFeedforward m_feedforward = new SimpleMotorFeedforward(1, 3);
+
+  // Simulation classes help us simulate our robot
+  private final AnalogGyroSim m_gyroSim = new AnalogGyroSim(m_gyro);
+  private final EncoderSim m_leftEncoderSim = new EncoderSim(m_leftEncoder);
+  private final EncoderSim m_rightEncoderSim = new EncoderSim(m_rightEncoder);
+  private final Field2d m_fieldSim = new Field2d();
+  private final LinearSystem<N2, N2, N2> m_drivetrainSystem
+      = LinearSystemId.identifyDrivetrainSystem(1.98, 0.2, 1.5, 0.3);
+  private final DifferentialDrivetrainSim m_drivetrainSimulator
+      = new DifferentialDrivetrainSim(m_drivetrainSystem, DCMotor.getCIM(2), 8, kTrackWidth,
+      kWheelRadius, null);
+
+  public Drivetrain() {
+    // Set the distance per pulse for the drive encoders. We can simply use the
+    // distance traveled for one rotation of the wheel divided by the encoder
+    // resolution.
+    m_leftEncoder.setDistancePerPulse(2 * Math.PI * kWheelRadius / kEncoderResolution);
+    m_rightEncoder.setDistancePerPulse(2 * Math.PI * kWheelRadius / kEncoderResolution);
+
+    m_leftEncoder.reset();
+    m_rightEncoder.reset();
+
+    m_rightGroup.setInverted(true);
+    SmartDashboard.putData("Field", m_fieldSim);
+  }
+
+  public void setSpeeds(DifferentialDriveWheelSpeeds speeds) {
+    var leftFeedforward = m_feedforward.calculate(speeds.leftMetersPerSecond);
+    var rightFeedforward = m_feedforward.calculate(speeds.rightMetersPerSecond);
+    double leftOutput = m_leftPIDController.calculate(m_leftEncoder.getRate(),
+        speeds.leftMetersPerSecond);
+    double rightOutput = m_rightPIDController.calculate(m_rightEncoder.getRate(),
+        speeds.rightMetersPerSecond);
+
+    m_leftGroup.setVoltage(leftOutput + leftFeedforward);
+    m_rightGroup.setVoltage(rightOutput + rightFeedforward);
+  }
+
+  public void drive(double xSpeed, double rot) {
+    setSpeeds(m_kinematics.toWheelSpeeds(new ChassisSpeeds(xSpeed, 0, rot)));
+  }
+
+  public void updateOdometry() {
+    m_odometry.update(m_gyro.getRotation2d(), m_leftEncoder.getDistance(),
+        m_rightEncoder.getDistance());
+  }
+
+  public void resetOdometry(Pose2d pose) {
+    m_leftEncoder.reset();
+    m_rightEncoder.reset();
+    m_drivetrainSimulator.setPose(pose);
+    m_odometry.resetPosition(pose, m_gyro.getRotation2d());
+  }
+
+  public Pose2d getPose() {
+    return m_odometry.getPoseMeters();
+  }
+
+  public void simulationPeriodic() {
+    // To update our simulation, we set motor voltage inputs, update the
+    // simulation, and write the simulated positions and velocities to our
+    // simulated encoder and gyro. We negate the right side so that positive
+    // voltages make the right side move forward.
+    m_drivetrainSimulator.setInputs(m_leftLeader.get() * RobotController.getInputVoltage(),
+        -m_rightLeader.get() * RobotController.getInputVoltage());
+    m_drivetrainSimulator.update(0.02);
+
+    m_leftEncoderSim.setDistance(m_drivetrainSimulator.getLeftPositionMeters());
+    m_leftEncoderSim.setRate(m_drivetrainSimulator.getLeftVelocityMetersPerSecond());
+    m_rightEncoderSim.setDistance(m_drivetrainSimulator.getRightPositionMeters());
+    m_rightEncoderSim.setRate(m_drivetrainSimulator.getRightVelocityMetersPerSecond());
+    m_gyroSim.setAngle(-m_drivetrainSimulator.getHeading().getDegrees());
+
+    m_fieldSim.setRobotPose(m_odometry.getPoseMeters());
+  }
+}

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/simpledifferentialdrivesimulation/Main.java

@@ -0,0 +1,29 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.first.wpilibj.examples.simpledifferentialdrivesimulation;
+
+import edu.wpi.first.wpilibj.RobotBase;
+
+/**
+ * Do NOT add any static variables to this class, or any initialization at all.
+ * Unless you know what you are doing, do not modify this file except to
+ * change the parameter class to the startRobot call.
+ */
+public final class Main {
+  private Main() {
+  }
+
+  /**
+   * Main initialization function. Do not perform any initialization here.
+   *
+   * <p>If you change your main robot class, change the parameter type.
+   */
+  public static void main(String... args) {
+    RobotBase.startRobot(Robot::new);
+  }
+}

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/simpledifferentialdrivesimulation/Robot.java

@@ -0,0 +1,83 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.first.wpilibj.examples.simpledifferentialdrivesimulation;
+
+import java.util.List;
+
+import edu.wpi.first.wpilibj.GenericHID;
+import edu.wpi.first.wpilibj.SlewRateLimiter;
+import edu.wpi.first.wpilibj.TimedRobot;
+import edu.wpi.first.wpilibj.Timer;
+import edu.wpi.first.wpilibj.XboxController;
+import edu.wpi.first.wpilibj.controller.RamseteController;
+import edu.wpi.first.wpilibj.geometry.Pose2d;
+import edu.wpi.first.wpilibj.geometry.Rotation2d;
+import edu.wpi.first.wpilibj.kinematics.ChassisSpeeds;
+import edu.wpi.first.wpilibj.trajectory.Trajectory;
+import edu.wpi.first.wpilibj.trajectory.TrajectoryConfig;
+import edu.wpi.first.wpilibj.trajectory.TrajectoryGenerator;
+
+public class Robot extends TimedRobot {
+  private final XboxController m_controller = new XboxController(0);
+
+  // Slew rate limiters to make joystick inputs more gentle; 1/3 sec from 0
+  // to 1.
+  private final SlewRateLimiter m_speedLimiter = new SlewRateLimiter(3);
+  private final SlewRateLimiter m_rotLimiter = new SlewRateLimiter(3);
+
+  private final Drivetrain m_drive = new Drivetrain();
+  private final RamseteController m_ramsete = new RamseteController();
+  private final Timer m_timer = new Timer();
+  private Trajectory m_trajectory;
+
+  @Override
+  public void robotInit() {
+    m_trajectory = TrajectoryGenerator.generateTrajectory(
+        new Pose2d(2, 2, new Rotation2d()), List.of(), new Pose2d(6, 4, new Rotation2d()),
+        new TrajectoryConfig(2, 2)
+    );
+  }
+
+  @Override
+  public void autonomousInit() {
+    m_timer.reset();
+    m_timer.start();
+    m_drive.resetOdometry(m_trajectory.getInitialPose());
+  }
+
+  @Override
+  public void autonomousPeriodic() {
+    double elapsed = m_timer.get();
+    Trajectory.State reference = m_trajectory.sample(elapsed);
+    ChassisSpeeds speeds = m_ramsete.calculate(m_drive.getPose(), reference);
+    m_drive.drive(speeds.vxMetersPerSecond, speeds.omegaRadiansPerSecond);
+    m_drive.updateOdometry();
+  }
+
+  @Override
+  @SuppressWarnings("LocalVariableName")
+  public void teleopPeriodic() {
+    // Get the x speed. We are inverting this because Xbox controllers return
+    // negative values when we push forward.
+    double xSpeed = -m_speedLimiter.calculate(m_controller.getY(GenericHID.Hand.kLeft))
+        * Drivetrain.kMaxSpeed;
+
+    // Get the rate of angular rotation. We are inverting this because we want a
+    // positive value when we pull to the left (remember, CCW is positive in
+    // mathematics). Xbox controllers return positive values when you pull to
+    // the right by default.
+    double rot = -m_rotLimiter.calculate(m_controller.getX(GenericHID.Hand.kRight))
+        * Drivetrain.kMaxAngularSpeed;
+    m_drive.drive(xSpeed, rot);
+  }
+
+  @Override
+  public void simulationPeriodic() {
+    m_drive.simulationPeriodic();
+  }
+}