Spartronics 2019 Destination: Deep Space robot code

Team 4915's code for DeepSpace. Derived from Team254's 2018 codebase.

The code is divided into several packages, each responsible for a different aspect of the robot function. This README explains setup instructions, the function of each package, and some of the variable naming conventions used. Additional information about each specific class can be found in that class' Java file.

Setup Instructions

General

• Clone this repo
• Run ./gradlew to download gradle and needed FRC libraries
• Run ./gradlew tasks to see available build options
• Enjoy!

Building/Deploying to the Robot

• Run ./gradlew build to build the code. Use the --info flag for more details
• Run ./gradlew deploy to deploy to the robot in Terminal (Mac) or Powershell (Windows)

Code Highlights

• Building with Gradle - this is now standard for FRC in 2019.
• Path following with a nonlinear feedback controller and splines. To control autonomous driving, the robot utilizes a nonlinear feedback controller and drives paths constructed of quintic Hermite splines.
• Path generation and visualization via Java app. Cheesy Path, a Java webapp, allows a user to quickly and easily create and visualize autonomous paths. It is located in the src/main/webapp directory and the com.spartronics4915.path package. Run with ./gradlew tomcatRunWar and open http://localhost:8080. To stop the server, run ./gradlew tomcatStop.
• Self-test modes for each subsystem Each subsystem contains a checkSystem() method that tests motor output currents and RPMs. These self tests allow us to quickly verify that all motors are working properly.
• Lidar Processing Even though this was not used on the final iteration of our robot code, we are still releasing our lidar processing code. This consisted of ICP algorithms to detect the scale within the points detected and sent by the Slamtec RPLIDAR A2 and can be found in the com.spartronics4915.frc2019.lidar package. Our RPLIDAR driver can be found here.

Package Functions

• com.spartronics4915.frc2019 Contains the robot's central functions and holds a file with all numerical constants used throughout the code. For example, the Robot class controls all routines depending on the robot state.

• com.spartronics4915.frc2019.auto Handles the execution of autonomous routines and contains the actions, creators, and modes packages.

• com.spartronics4915.frc2019.auto.actions Contains all actions used during the autonomous period, which all share a common interface, Action (also in this package). Examples include shooting cubes, driving a trajectory, or moving the elevator. Routines interact with the Subsystems, which interact with the hardware.

• com.spartronics4915.frc2019.auto.creators Contains all the auto mode creators, which select the correct auto mode to run based on user input and FMS data.

• com.spartronics4915.frc2019.auto.modes Contains all autonomous modes. Autonomous modes consist of a list of autonomous actions executed in a certain order.

• com.spartronics4915.frc2019.controlboard Contains all the code for the different control boards. This allows any combination of driver station joysticks, button board, and Xbox Controllers to be used for both driving and operating. These are controlled by booleans in Constants.java.

• com.spartronics4915.frc2019.lidar Contains classes that are used to communicate with the Slamtec RPLIDAR A2 and to store and process points sent by the lidar.

• com.spartronics4915.frc2019.lidar.icp Contains the algorithms for processing points sent by the lidar.

• com.spartronics4915.frc2019.loops Loops are routines that run periodically on the robot, such as calculating robot pose, processing vision feedback, or updating subsystems. All loops implement the Loop interface and are handled (started, stopped, added) by the Looper class, which runs at 200 Hz. The Robot class has one main looper, mEnabledLooper, that runs all loops when the robot is enabled.

• com.spartronics4915.frc2019.paths Contains the generator for all of the trajectories that the robot drives during autonomous period.

• com.spartronics4915.frc2019.planners Loops are routines that run periodically on the robot, such as calculating robot pose, processing vision feedback, or updating subsystems. All loops implement the Loop interface and are handled (started, stopped, added) by the Looper class, which runs at 200 Hz. The Robot class has one main looper, mEnabledLooper, that runs all loops when the robot is enabled.

• com.spartronics4915.frc2019.statemachines Contains the state machines for the intake and overall superstructure.

• com.spartronics4915.frc2019.states Contains states and other classes used in the subsystem and state machine classes.

• com.spartronics4915.frc2019.subsystems Subsystems are consolidated into one central class per subsystem, all of which extend the Subsystem abstract class. Each subsystem uses state machines for control. Each subsystem is also a singleton, meaning that there is only one instance of each. To modify a subsystem, one would get the instance of the subsystem and change its state. The Subsystem class will work on setting the desired state.

• com.spartronics4915.lib.drivers Contains a set of custom classes for TalonSRXs.

• com.spartronics4915.lib.geometry Contains a set of classes that represent various geometric entities.

• com.spartronics4915.lib.physics Contains classes that model DC motor transmissions and differential drive characterization.

• com.spartronics4915.lib.spline Contains the code for generating and optimizing splines.

• com.spartronics4915.lib.trajectory Contains classes for following and storing trajectories.

• com.spartronics4915.lib.trajectory.timing Contains classes for fitting trajectories with time profiles.

• com.spartronics4915.lib.util A collection of assorted utilities classes used in the robot code. Check each file for more information.

Variable Naming Conventions

• k*** (i.e. kDriveWheelTrackWidthInches): Final constants, especially those found in the Constants.java file
• m*** (i.e. mIsHighGear): Private instance variables