CTRE Generated Swerve Code with Maple-Sim

This is a modified version of the CTRE Generated Swerve Code, enhanced with Maple-Sim for better simulation capabilities.

This integration enables a realistic physics-based simulation using Maple-Sim with CTRE Swerve. You can fine-tune autonomous modes, optimize subsystems, and test advanced interactions in a simulated environment.

Using with New Projects

To integrate Maple-Sim with new CTRE swerve projects:

1. Generate the TunerConstants.java file using Phoenix Tuner X.
2. Place the generated file in your project at generated/TunerConstants.java.
3. Deploy the code to your robot!

Using with Existing Projects

For existing CTRE swerve projects, follow these steps to integrate the simulation:

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Prerequisites

Ensure your project was generated using Phoenix Tuner X 2025.2.0.0+.

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Install Maple-Sim

Install the latest version of Maple-Sim. Refer to the installation guide for detailed instructions.

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Add the Utility Class

Download this source file and place it in the src/main/java/frc/robot/utils/simulation directory of your project.

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Modify the Drive Subsystem Code

Update your subsystems/CommandSwerveDrivetrain.java file as follows:

1. Change the Simulation Implementation Replace the existing startSimThread method with the code below:

   private MapleSimSwerveDrivetrain mapleSimSwerveDrivetrain = null;
   private void startSimThread() {
       mapleSimSwerveDrivetrain = new MapleSimSwerveDrivetrain(
               Seconds.of(kSimLoopPeriod),
               // TODO: modify the following constants according to your robot
               Pounds.of(115), // robot weight
               Inches.of(30), // bumper length
               Inches.of(30), // bumper width
               DCMotor.getKrakenX60(1), // drive motor type
               DCMotor.getFalcon500(1), // steer motor type
               1.2, // wheel COF
               getModuleLocations(),
               getPigeon2(),
               getModules(),
               TunerConstants.FrontLeft,
               TunerConstants.FrontRight,
               TunerConstants.BackLeft,
               TunerConstants.BackRight);
       /* Run simulation at a faster rate so PID gains behave more reasonably */
       m_simNotifier = new Notifier(mapleSimSwerveDrivetrain::update);
       m_simNotifier.startPeriodic(kSimLoopPeriod);
   }

2. Regulate the Module Constants Modify the constructor to regulate the module constants. Note: This will modify your module constants during simulation to avoid known bugs during, skips if running on a real robot.

   /** ... */
   public CommandSwerveDrivetrain(
           SwerveDrivetrainConstants drivetrainConstants,
           double odometryUpdateFrequency,
           SwerveModuleConstants<?, ?, ?>... modules) {
       super(
               drivetrainConstants,
               odometryUpdateFrequency,
               // modules
               MapleSimSwerveDrivetrain.regulateModuleConstantsForSimulation(modules));
       if (Utils.isSimulation()) {
           startSimThread();
       }
       configureAutoBuilder();
   }
   
   /** ... */
   public CommandSwerveDrivetrain(
           SwerveDrivetrainConstants drivetrainConstants,
           double odometryUpdateFrequency,
           Matrix<N3, N1> odometryStandardDeviation,
           Matrix<N3, N1> visionStandardDeviation,
           SwerveModuleConstants<?, ?, ?>... modules) {
       super(
               drivetrainConstants,
               odometryUpdateFrequency,
               odometryStandardDeviation,
               visionStandardDeviation,
               // modules
               MapleSimSwerveDrivetrain.regulateModuleConstantsForSimulation(modules));
       if (Utils.isSimulation()) {
           startSimThread();
       }
       configureAutoBuilder();
   }

3. Reset the Robot Simulation Pose Update the resetPose method to sync simulation and real-world poses:

   @Override
   public void resetPose(Pose2d pose) {
       if (this.mapleSimSwerveDrivetrain != null)
           mapleSimSwerveDrivetrain.mapleSimDrive.setSimulationWorldPose(pose);
       Timer.delay(0.05); // Wait for simulation to update
       super.resetPose(pose);
   }