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T Grinch edited this page Nov 10, 2023 · 31 revisions

Features and Resources

How to create a swerve drive?

YAGSL is unique in the fact that you can create a swerve drive based entirely off of JSON configuration files. The JSON configuration files should be located in the deploy directory. You can also create the Configuration objects manually and instantiate your Swerve Drive that way.

How to create a SwerveDrive using JSON.

This example program creates the SwerveDrive in the SwerveSubsystem, as you should only interact with it in the SwerveSubsystem if you are using command based programming.

import java.io.File;
import edu.wpi.first.wpilibj.Filesystem;
import swervelib.parser.SwerveParser;
import swervelib.SwerveDrive;
import edu.wpi.first.math.util.Units;


double maximumSpeed = Units.feetToMeters(4.5)
File swerveJsonDirectory = new File(Filesystem.getDeployDirectory(),"swerve");
SwerveDrive  swerveDrive = new SwerveParser(directory).createSwerveDrive(maximumSpeed);

This way is fast and easy, no more large unmaintainable and daunting constants file to worry about! To create a JSON directory look at the JSON documentation.

Creating a swerve drive.

  • Install NavX, ReduxLib, CTRE, and REV vendor dependencies.
  • Install YAGSL (https://broncbotz3481.github.io/YAGSL-Lib/yagsl/yagsl.json)
  • Copy example JSON directory or create your own then move it into src/main/frc/deploy/swerve or generate one from here
  • Create SwerveDrive from JSON directory via SwerveDrive drive = new SwerveParser(new File(Filesystem.getDeployDirectory(), "swerve")).createSwerveDrive();
  • View the java docs in docs/index.html
  • Experiment!

Migrating Old Configuration Files

  1. Delete wheelDiamter, gearRatio, encoderPulsePerRotation from physicalproperties.json
  2. Add optimalVoltage to physicalproperties.json
  3. Delete maxSpeed and optimalVoltage from swervedrive.json
  4. IF a swerve module doesn't have the same drive motor or steering motor as the rest of the swerve drive you MUST specify a conversionFactor for BOTH the drive and steering motor in the modules configuration JSON file. IF one of the motors is the same as the rest of the swerve drive and you want to use that conversionFactor, set the conversionFactor in the module JSON configuration to 0.
  5. You MUST specify the maximum speed when creating a SwerveDrive through new SwerveParser(directory).createSwerveDrive(maximumSpeed);
  6. IF you do not want to set conversionFactor in swervedrive.json. You can pass it into the constructor as a parameter like this
double DriveConversionFactor = SwerveMath.calculateMetersPerRotation(Units.inchesToMeters(WHEEL_DIAMETER), GEAR_RATIO, ENCODER_RESOLUTION);
double SteeringConversionFactor = SwerveMath.calculateDegreesPerSteeringRotation(GEAR_RATIO, ENCODER_RESOLUTION);
new SwerveParser(directory).createSwerveDrive(maximumSpeed, SteeringConversionFactor, DriveConversionFactor);

Contributions

This library is based off of 95's SwervyBot code in addition to a wide variety of other code bases. A huge thank you to every team which has open sourced their swerve code!