Who are we?

FRC team 1778, Chill Out!, is a FIRST Robotics team from Mountlake Terrace, Washington. This page contains meeting summaries and any other information benefitting our programming team.

Useful links for programmers:

Javadocs for WPILib, RevLib API, Phoenix 6, Java 21.
Repositories for Scrappy and Zappy
Controls Engineering for FRC

Our main two programmers are:

Meeting summaries follow.

Thursday, October 3rd

CAN bus and IDs (Using CAN Devices, CAN Wiring Basics)
NEOs and Krakens
Gear reductions
PID controllers (PID Control in WPILib, Introduction to PID)
Battery and driving
Our GitHub (see above) and looking at src/main/java/org/chillout1778.

Tuesday, October 15

Kotlin classes and objects.
Example: our swerve code (Swerve.kt, SwerveModule.kt).
PDH (power distribution hub), network switch, radio (how to program). Todo: add which network switch and radio exactly are on our robots.

Thursday, October 17

All programmers now have a laptop with IntelliJ IDEA installed, and a repository with GradleRIO and the REVLib and Phoenix6 vendordeps.

Tuesday, October 22

Everyone has now written a flywheel subsystem with two Krakens (one inverted), using a velocity PID and a gear ratio.
Learned about commands and created a simple command that changes the PID setpoint and exits when the flywheel is within tolerance of that setpoint.
Figured out that you need to press “refresh Gradle” in the right toolbar if IntelliJ, for some reason, doesn’t know about any library code.
Rushed through the basic idea of feedforwards.

Thursday, October 24

Started getting setup for swerve codebase. Added a new testing branch to the offseason bot code (can reference the code for Zappy Feet). Everyone knows how to pull from that branch now.

Checklist for next year’s swerve drive:
- switch turn motors from CANSparkMax to TalonFX
- remove resetting relative encoders from absolute encoders when robot stops moving for a while (unnecessary)
- discretize ChassisSpeeds for odometry
- streamline setting encoder offsets (add a dashboard button to save them to a file on the rio, then read that file on startup)
- characterize drive train so we can use feedforward for auto
- do pose estimation (and properly)

Saturday, October 26

Setup more development stuff and got Pathplanner installed on all new programmers’ computers. Started adding people to the LICENSE file.
Derivations to estimate kA from constant voltage graphs.

Tuesday, November 5

Measuring and using CANcoder offsets
Converting chassis speeds from field-relative (joystick input) to robot relative coordinate systems
Discretizing chassis speeds
Optimizing swerve states so that module heading never travels more than 90 degrees
Cosine compensation: drive modules less if they’re facing the wrong direction (or, more mathematically — drive at the component of commanded velocity which is in the direction of our current heading)
Using PIDs and feedforwards for the drive motors — aka, closed loop control
Learned about Sendables, that is, how to display robot data on the dashboard.
Learned about unit circle trigonometry, vectors, and how to convert from r and θ (distance and angle) to x and y.

Thursday, November 7

Discussed Subsystems and Command lifetimes, as well as Triggers (in passing).
Implemented some commands using CoroutineCommand.
Discord discussion of faster update loops.

Checklist: do Phoenix6 status signal handling properly!

Sunday, November 10

Links on how swerve discretization really works:
- How (and why) to raise e to the power of a matrix (video)
- Lie theory for the roboticist (video)
- Lie Groups for 2D and 3D Transformations, section 5.2, “SE(2): Rigid transformations in 2D space”
- Implementations of the SE(2) to se(2) logarithm: Manif, WPILib, and Sophus
- Simon’s derivations for the logarithm
- A micro Lie theory for state estimation in robotics, appendix C, “The 2D rigid motion group SE(2)”
- Lie groups, algebras, and brackets (playlist)
- Exponential Coordinates of Rigid-Body Motion (video)
- Lie Groups and Rigid Body Kinematics
- Controls Engineering in the FIRST Robotics Competition, section 10.2, “Pose exponential”

Monday, November 11

Link: Spartan Series / Mechanical Design for Controllability (video)

Tuesday, November 12

Replaced the test board’s RoboRIO 1 with a RoboRIO 2 for better power wiring (robot wiring guide)
Flashed a new microSD card for the RoboRIO, by grabbing RoboRIO firmware from the RoboRIO imaging tool but using Balena Etcher to actually burn it to the card, then running the roborio team number setter.
Changed build.gradle to use Java version 17 (download it here) so that the output actually runs on the RIO.
Ran a TalonFX based on input from the drone controller (using GenericHID).
Tried to inspect motor velocity at constant voltage; Shuffleboard wouldn’t run, so just printed data to the console.

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