Add Roadrunner

TeamCode/util/AssetsTrajectoryManager.java

@@ -0,0 +1,70 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import androidx.annotation.Nullable;
+
+import com.acmerobotics.roadrunner.trajectory.Trajectory;
+import com.acmerobotics.roadrunner.trajectory.TrajectoryBuilder;
+import com.acmerobotics.roadrunner.trajectory.config.TrajectoryConfig;
+import com.acmerobotics.roadrunner.trajectory.config.TrajectoryConfigManager;
+import com.acmerobotics.roadrunner.trajectory.config.TrajectoryGroupConfig;
+
+import org.firstinspires.ftc.robotcore.internal.system.AppUtil;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Set of utilities for loading trajectories from assets (the plugin save location).
+ */
+public class AssetsTrajectoryManager {
+
+    /**
+     * Loads the group config.
+     */
+    public static @Nullable
+    TrajectoryGroupConfig loadGroupConfig() {
+        try {
+            InputStream inputStream = AppUtil.getDefContext().getAssets().open(
+                    "trajectory/" + TrajectoryConfigManager.GROUP_FILENAME);
+            return TrajectoryConfigManager.loadGroupConfig(inputStream);
+        } catch (IOException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Loads a trajectory config with the given name.
+     */
+    public static @Nullable TrajectoryConfig loadConfig(String name) {
+        try {
+            InputStream inputStream = AppUtil.getDefContext().getAssets().open(
+                    "trajectory/" + name + ".yaml");
+            return TrajectoryConfigManager.loadConfig(inputStream);
+        } catch (IOException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Loads a trajectory builder with the given name.
+     */
+    public static @Nullable TrajectoryBuilder loadBuilder(String name) {
+        TrajectoryGroupConfig groupConfig = loadGroupConfig();
+        TrajectoryConfig config = loadConfig(name);
+        if (groupConfig == null || config == null) {
+            return null;
+        }
+        return config.toTrajectoryBuilder(groupConfig);
+    }
+
+    /**
+     * Loads a trajectory with the given name.
+     */
+    public static @Nullable Trajectory load(String name) {
+        TrajectoryBuilder builder = loadBuilder(name);
+        if (builder == null) {
+            return null;
+        }
+        return builder.build();
+    }
+}

TeamCode/util/AxesSigns.java

@@ -0,0 +1,45 @@
+package org.firstinspires.ftc.teamcode.util;
+
+/**
+ * IMU axes signs in the order XYZ (after remapping).
+ */
+public enum AxesSigns {
+    PPP(0b000),
+    PPN(0b001),
+    PNP(0b010),
+    PNN(0b011),
+    NPP(0b100),
+    NPN(0b101),
+    NNP(0b110),
+    NNN(0b111);
+
+    public final int bVal;
+
+    AxesSigns(int bVal) {
+        this.bVal = bVal;
+    }
+
+    public static AxesSigns fromBinaryValue(int bVal) {
+        int maskedVal = bVal & 0x07;
+        switch (maskedVal) {
+            case 0b000:
+                return AxesSigns.PPP;
+            case 0b001:
+                return AxesSigns.PPN;
+            case 0b010:
+                return AxesSigns.PNP;
+            case 0b011:
+                return AxesSigns.PNN;
+            case 0b100:
+                return AxesSigns.NPP;
+            case 0b101:
+                return AxesSigns.NPN;
+            case 0b110:
+                return AxesSigns.NNP;
+            case 0b111:
+                return AxesSigns.NNN;
+            default:
+                throw new IllegalStateException("Unexpected value for maskedVal: " + maskedVal);
+        }
+    }
+}

TeamCode/util/AxisDirection.java

@@ -0,0 +1,8 @@
+package org.firstinspires.ftc.teamcode.util;
+
+/**
+ * A direction for an axis to be remapped to
+ */
+public enum AxisDirection {
+    POS_X, NEG_X, POS_Y, NEG_Y, POS_Z, NEG_Z
+}

TeamCode/util/DashboardUtil.java

@@ -0,0 +1,54 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import com.acmerobotics.dashboard.canvas.Canvas;
+import com.acmerobotics.roadrunner.geometry.Pose2d;
+import com.acmerobotics.roadrunner.geometry.Vector2d;
+import com.acmerobotics.roadrunner.path.Path;
+
+import java.util.List;
+
+/**
+ * Set of helper functions for drawing Road Runner paths and trajectories on dashboard canvases.
+ */
+public class DashboardUtil {
+    private static final double DEFAULT_RESOLUTION = 2.0; // distance units; presumed inches
+    private static final double ROBOT_RADIUS = 9; // in
+
+
+    public static void drawPoseHistory(Canvas canvas, List<Pose2d> poseHistory) {
+        double[] xPoints = new double[poseHistory.size()];
+        double[] yPoints = new double[poseHistory.size()];
+        for (int i = 0; i < poseHistory.size(); i++) {
+            Pose2d pose = poseHistory.get(i);
+            xPoints[i] = pose.getX();
+            yPoints[i] = pose.getY();
+        }
+        canvas.strokePolyline(xPoints, yPoints);
+    }
+
+    public static void drawSampledPath(Canvas canvas, Path path, double resolution) {
+        int samples = (int) Math.ceil(path.length() / resolution);
+        double[] xPoints = new double[samples];
+        double[] yPoints = new double[samples];
+        double dx = path.length() / (samples - 1);
+        for (int i = 0; i < samples; i++) {
+            double displacement = i * dx;
+            Pose2d pose = path.get(displacement);
+            xPoints[i] = pose.getX();
+            yPoints[i] = pose.getY();
+        }
+        canvas.strokePolyline(xPoints, yPoints);
+    }
+
+    public static void drawSampledPath(Canvas canvas, Path path) {
+        drawSampledPath(canvas, path, DEFAULT_RESOLUTION);
+    }
+
+    public static void drawRobot(Canvas canvas, Pose2d pose) {
+        canvas.strokeCircle(pose.getX(), pose.getY(), ROBOT_RADIUS);
+        Vector2d v = pose.headingVec().times(ROBOT_RADIUS);
+        double x1 = pose.getX() + v.getX() / 2, y1 = pose.getY() + v.getY() / 2;
+        double x2 = pose.getX() + v.getX(), y2 = pose.getY() + v.getY();
+        canvas.strokeLine(x1, y1, x2, y2);
+    }
+}

TeamCode/util/Encoder.java

@@ -0,0 +1,125 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import com.acmerobotics.roadrunner.util.NanoClock;
+import com.qualcomm.robotcore.hardware.DcMotorEx;
+import com.qualcomm.robotcore.hardware.DcMotorSimple;
+
+/**
+ * Wraps a motor instance to provide corrected velocity counts and allow reversing independently of the corresponding
+ * slot's motor direction
+ */
+public class Encoder {
+    private final static int CPS_STEP = 0x10000;
+
+    private static double inverseOverflow(double input, double estimate) {
+        // convert to uint16
+        int real = (int) input & 0xffff;
+        // initial, modulo-based correction: it can recover the remainder of 5 of the upper 16 bits
+        // because the velocity is always a multiple of 20 cps due to Expansion Hub's 50ms measurement window
+        real += ((real % 20) / 4) * CPS_STEP;
+        // estimate-based correction: it finds the nearest multiple of 5 to correct the upper bits by
+        real += Math.round((estimate - real) / (5 * CPS_STEP)) * 5 * CPS_STEP;
+        return real;
+    }
+
+    public enum Direction {
+        FORWARD(1),
+        REVERSE(-1);
+
+        private int multiplier;
+
+        Direction(int multiplier) {
+            this.multiplier = multiplier;
+        }
+
+        public int getMultiplier() {
+            return multiplier;
+        }
+    }
+
+    private DcMotorEx motor;
+    private NanoClock clock;
+
+    private Direction direction;
+
+    private int lastPosition;
+    private int velocityEstimateIdx;
+    private double[] velocityEstimates;
+    private double lastUpdateTime;
+
+    public Encoder(DcMotorEx motor, NanoClock clock) {
+        this.motor = motor;
+        this.clock = clock;
+
+        this.direction = Direction.FORWARD;
+
+        this.lastPosition = 0;
+        this.velocityEstimates = new double[3];
+        this.lastUpdateTime = clock.seconds();
+    }
+
+    public Encoder(DcMotorEx motor) {
+        this(motor, NanoClock.system());
+    }
+
+    public Direction getDirection() {
+        return direction;
+    }
+
+    private int getMultiplier() {
+        return getDirection().getMultiplier() * (motor.getDirection() == DcMotorSimple.Direction.FORWARD ? 1 : -1);
+    }
+
+    /**
+     * Allows you to set the direction of the counts and velocity without modifying the motor's direction state
+     * @param direction either reverse or forward depending on if encoder counts should be negated
+     */
+    public void setDirection(Direction direction) {
+        this.direction = direction;
+    }
+
+    /**
+     * Gets the position from the underlying motor and adjusts for the set direction.
+     * Additionally, this method updates the velocity estimates used for compensated velocity
+     *
+     * @return encoder position
+     */
+    public int getCurrentPosition() {
+        int multiplier = getMultiplier();
+        int currentPosition = motor.getCurrentPosition() * multiplier;
+        if (currentPosition != lastPosition) {
+            double currentTime = clock.seconds();
+            double dt = currentTime - lastUpdateTime;
+            velocityEstimates[velocityEstimateIdx] = (currentPosition - lastPosition) / dt;
+            velocityEstimateIdx = (velocityEstimateIdx + 1) % 3;
+            lastPosition = currentPosition;
+            lastUpdateTime = currentTime;
+        }
+        return currentPosition;
+    }
+
+    /**
+     * Gets the velocity directly from the underlying motor and compensates for the direction
+     * See {@link #getCorrectedVelocity} for high (>2^15) counts per second velocities (such as on REV Through Bore)
+     *
+     * @return raw velocity
+     */
+    public double getRawVelocity() {
+        int multiplier = getMultiplier();
+        return motor.getVelocity() * multiplier;
+    }
+
+    /**
+     * Uses velocity estimates gathered in {@link #getCurrentPosition} to estimate the upper bits of velocity
+     * that are lost in overflow due to velocity being transmitted as 16 bits.
+     * CAVEAT: must regularly call {@link #getCurrentPosition} for the compensation to work correctly.
+     *
+     * @return corrected velocity
+     */
+    public double getCorrectedVelocity() {
+        double median = velocityEstimates[0] > velocityEstimates[1]
+                ? Math.max(velocityEstimates[1], Math.min(velocityEstimates[0], velocityEstimates[2]))
+                : Math.max(velocityEstimates[0], Math.min(velocityEstimates[1], velocityEstimates[2]));
+        return inverseOverflow(getRawVelocity(), median);
+    }
+}

TeamCode/util/LogFiles.java

@@ -0,0 +1,273 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+
+import com.acmerobotics.roadrunner.geometry.Pose2d;
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.qualcomm.hardware.rev.RevHubOrientationOnRobot;
+import com.qualcomm.robotcore.eventloop.opmode.OpMode;
+import com.qualcomm.robotcore.eventloop.opmode.OpModeManagerImpl;
+import com.qualcomm.robotcore.eventloop.opmode.OpModeManagerNotifier;
+import com.qualcomm.robotcore.util.RobotLog;
+import com.qualcomm.robotcore.util.WebHandlerManager;
+
+import org.firstinspires.ftc.ftccommon.external.WebHandlerRegistrar;
+import org.firstinspires.ftc.robotcore.internal.system.AppUtil;
+import org.firstinspires.ftc.teamcode.drive.DriveConstants;
+import org.firstinspires.ftc.teamcode.drive.SampleMecanumDrive;
+import org.firstinspires.ftc.teamcode.drive.SampleTankDrive;
+import org.firstinspires.ftc.teamcode.drive.StandardTrackingWheelLocalizer;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Date;
+import java.util.List;
+import java.util.Objects;
+
+import fi.iki.elonen.NanoHTTPD;
+
+public final class LogFiles {
+    private static final File ROOT =
+            new File(AppUtil.ROOT_FOLDER + "/RoadRunner/logs/");
+
+    public static LogFile log = new LogFile("uninitialized");
+
+    public static class LogFile {
+        public String version = "quickstart1 v2";
+
+        public String opModeName;
+        public long msInit = System.currentTimeMillis();
+        public long nsInit = System.nanoTime();
+        public long nsStart, nsStop;
+
+        public double ticksPerRev = DriveConstants.TICKS_PER_REV;
+        public double maxRpm = DriveConstants.MAX_RPM;
+        public boolean runUsingEncoder = DriveConstants.RUN_USING_ENCODER;
+        public double motorP = DriveConstants.MOTOR_VELO_PID.p;
+        public double motorI = DriveConstants.MOTOR_VELO_PID.i;
+        public double motorD = DriveConstants.MOTOR_VELO_PID.d;
+        public double motorF = DriveConstants.MOTOR_VELO_PID.f;
+        public double wheelRadius = DriveConstants.WHEEL_RADIUS;
+        public double gearRatio = DriveConstants.GEAR_RATIO;
+        public double trackWidth = DriveConstants.TRACK_WIDTH;
+        public double kV = DriveConstants.kV;
+        public double kA = DriveConstants.kA;
+        public double kStatic = DriveConstants.kStatic;
+        public double maxVel = DriveConstants.MAX_VEL;
+        public double maxAccel = DriveConstants.MAX_ACCEL;
+        public double maxAngVel = DriveConstants.MAX_ANG_VEL;
+        public double maxAngAccel = DriveConstants.MAX_ANG_ACCEL;
+
+        public double mecTransP = SampleMecanumDrive.TRANSLATIONAL_PID.kP;
+        public double mecTransI = SampleMecanumDrive.TRANSLATIONAL_PID.kI;
+        public double mecTransD = SampleMecanumDrive.TRANSLATIONAL_PID.kD;
+        public double mecHeadingP = SampleMecanumDrive.HEADING_PID.kP;
+        public double mecHeadingI = SampleMecanumDrive.HEADING_PID.kI;
+        public double mecHeadingD = SampleMecanumDrive.HEADING_PID.kD;
+        public double mecLateralMultiplier = SampleMecanumDrive.LATERAL_MULTIPLIER;
+
+        public double tankAxialP = SampleTankDrive.AXIAL_PID.kP;
+        public double tankAxialI = SampleTankDrive.AXIAL_PID.kI;
+        public double tankAxialD = SampleTankDrive.AXIAL_PID.kD;
+        public double tankCrossTrackP = SampleTankDrive.CROSS_TRACK_PID.kP;
+        public double tankCrossTrackI = SampleTankDrive.CROSS_TRACK_PID.kI;
+        public double tankCrossTrackD = SampleTankDrive.CROSS_TRACK_PID.kD;
+        public double tankHeadingP = SampleTankDrive.HEADING_PID.kP;
+        public double tankHeadingI = SampleTankDrive.HEADING_PID.kI;
+        public double tankHeadingD = SampleTankDrive.HEADING_PID.kD;
+
+        public double trackingTicksPerRev = StandardTrackingWheelLocalizer.TICKS_PER_REV;
+        public double trackingWheelRadius = StandardTrackingWheelLocalizer.WHEEL_RADIUS;
+        public double trackingGearRatio = StandardTrackingWheelLocalizer.GEAR_RATIO;
+        public double trackingLateralDistance = StandardTrackingWheelLocalizer.LATERAL_DISTANCE;
+        public double trackingForwardOffset = StandardTrackingWheelLocalizer.FORWARD_OFFSET;
+
+        public RevHubOrientationOnRobot.LogoFacingDirection LOGO_FACING_DIR = DriveConstants.LOGO_FACING_DIR;
+        public RevHubOrientationOnRobot.UsbFacingDirection USB_FACING_DIR = DriveConstants.USB_FACING_DIR;
+
+        public List<Long> nsTimes = new ArrayList<>();
+
+        public List<Double> targetXs = new ArrayList<>();
+        public List<Double> targetYs = new ArrayList<>();
+        public List<Double> targetHeadings = new ArrayList<>();
+
+        public List<Double> xs = new ArrayList<>();
+        public List<Double> ys = new ArrayList<>();
+        public List<Double> headings = new ArrayList<>();
+
+        public List<Double> voltages = new ArrayList<>();
+
+        public List<List<Integer>> driveEncPositions = new ArrayList<>();
+        public List<List<Integer>> driveEncVels = new ArrayList<>();
+        public List<List<Integer>> trackingEncPositions = new ArrayList<>();
+        public List<List<Integer>> trackingEncVels = new ArrayList<>();
+
+        public LogFile(String opModeName) {
+            this.opModeName = opModeName;
+        }
+    }
+
+    public static void record(
+            Pose2d targetPose, Pose2d pose, double voltage,
+            List<Integer> lastDriveEncPositions, List<Integer> lastDriveEncVels, List<Integer> lastTrackingEncPositions, List<Integer> lastTrackingEncVels
+    ) {
+        long nsTime = System.nanoTime();
+        if (nsTime - log.nsStart > 3 * 60 * 1_000_000_000L) {
+            return;
+        }
+
+        log.nsTimes.add(nsTime);
+
+        log.targetXs.add(targetPose.getX());
+        log.targetYs.add(targetPose.getY());
+        log.targetHeadings.add(targetPose.getHeading());
+
+        log.xs.add(pose.getX());
+        log.ys.add(pose.getY());
+        log.headings.add(pose.getHeading());
+
+        log.voltages.add(voltage);
+
+        while (log.driveEncPositions.size() < lastDriveEncPositions.size()) {
+            log.driveEncPositions.add(new ArrayList<>());
+        }
+        while (log.driveEncVels.size() < lastDriveEncVels.size()) {
+            log.driveEncVels.add(new ArrayList<>());
+        }
+        while (log.trackingEncPositions.size() < lastTrackingEncPositions.size()) {
+            log.trackingEncPositions.add(new ArrayList<>());
+        }
+        while (log.trackingEncVels.size() < lastTrackingEncVels.size()) {
+            log.trackingEncVels.add(new ArrayList<>());
+        }
+
+        for (int i = 0; i < lastDriveEncPositions.size(); i++) {
+            log.driveEncPositions.get(i).add(lastDriveEncPositions.get(i));
+        }
+        for (int i = 0; i < lastDriveEncVels.size(); i++) {
+            log.driveEncVels.get(i).add(lastDriveEncVels.get(i));
+        }
+        for (int i = 0; i < lastTrackingEncPositions.size(); i++) {
+            log.trackingEncPositions.get(i).add(lastTrackingEncPositions.get(i));
+        }
+        for (int i = 0; i < lastTrackingEncVels.size(); i++) {
+            log.trackingEncVels.get(i).add(lastTrackingEncVels.get(i));
+        }
+    }
+
+    private static final OpModeManagerNotifier.Notifications notifHandler = new OpModeManagerNotifier.Notifications() {
+        @SuppressLint("SimpleDateFormat")
+        final DateFormat dateFormat = new SimpleDateFormat("yyyy_MM_dd__HH_mm_ss_SSS");
+
+        final ObjectWriter jsonWriter = new ObjectMapper(new JsonFactory())
+                .writerWithDefaultPrettyPrinter();
+
+        @Override
+        public void onOpModePreInit(OpMode opMode) {
+            log = new LogFile(opMode.getClass().getCanonicalName());
+
+            // clean up old files
+            File[] fs = Objects.requireNonNull(ROOT.listFiles());
+            Arrays.sort(fs, (a, b) -> Long.compare(a.lastModified(), b.lastModified()));
+            long totalSizeBytes = 0;
+            for (File f : fs) {
+                totalSizeBytes += f.length();
+            }
+
+            int i = 0;
+            while (i < fs.length && totalSizeBytes >= 32 * 1000 * 1000) {
+                totalSizeBytes -= fs[i].length();
+                if (!fs[i].delete()) {
+                    RobotLog.setGlobalErrorMsg("Unable to delete file " + fs[i].getAbsolutePath());
+                }
+                ++i;
+            }
+        }
+
+        @Override
+        public void onOpModePreStart(OpMode opMode) {
+            log.nsStart = System.nanoTime();
+        }
+
+        @Override
+        public void onOpModePostStop(OpMode opMode) {
+            log.nsStop = System.nanoTime();
+
+            if (!(opMode instanceof OpModeManagerImpl.DefaultOpMode)) {
+                //noinspection ResultOfMethodCallIgnored
+                ROOT.mkdirs();
+
+                String filename = dateFormat.format(new Date(log.msInit)) + "__" + opMode.getClass().getSimpleName() + ".json";
+                File file = new File(ROOT, filename);
+                try {
+                    jsonWriter.writeValue(file, log);
+                } catch (IOException e) {
+                    RobotLog.setGlobalErrorMsg(new RuntimeException(e),
+                            "Unable to write data to " + file.getAbsolutePath());
+                }
+            }
+        }
+    };
+
+    @WebHandlerRegistrar
+    public static void registerRoutes(Context context, WebHandlerManager manager) {
+        //noinspection ResultOfMethodCallIgnored
+        ROOT.mkdirs();
+
+        // op mode manager only stores a weak reference, so we need to keep notifHandler alive ourselves
+        // don't use @OnCreateEventLoop because it's unreliable
+        OpModeManagerImpl.getOpModeManagerOfActivity(
+                AppUtil.getInstance().getActivity()
+        ).registerListener(notifHandler);
+
+        manager.register("/logs", session -> {
+            final StringBuilder sb = new StringBuilder();
+            sb.append("<!doctype html><html><head><title>Logs</title></head><body><ul>");
+            File[] fs = Objects.requireNonNull(ROOT.listFiles());
+            Arrays.sort(fs, (a, b) -> Long.compare(b.lastModified(), a.lastModified()));
+            for (File f : fs) {
+                sb.append("<li><a href=\"/logs/download?file=");
+                sb.append(f.getName());
+                sb.append("\" download=\"");
+                sb.append(f.getName());
+                sb.append("\">");
+                sb.append(f.getName());
+                sb.append("</a></li>");
+            }
+            sb.append("</ul></body></html>");
+            return NanoHTTPD.newFixedLengthResponse(NanoHTTPD.Response.Status.OK,
+                    NanoHTTPD.MIME_HTML, sb.toString());
+        });
+
+        manager.register("/logs/download", session -> {
+            final String[] pairs = session.getQueryParameterString().split("&");
+            if (pairs.length != 1) {
+                return NanoHTTPD.newFixedLengthResponse(NanoHTTPD.Response.Status.BAD_REQUEST,
+                        NanoHTTPD.MIME_PLAINTEXT, "expected one query parameter, got " + pairs.length);
+            }
+
+            final String[] parts = pairs[0].split("=");
+            if (!parts[0].equals("file")) {
+                return NanoHTTPD.newFixedLengthResponse(NanoHTTPD.Response.Status.BAD_REQUEST,
+                        NanoHTTPD.MIME_PLAINTEXT, "expected file query parameter, got " + parts[0]);
+            }
+
+            File f = new File(ROOT, parts[1]);
+            if (!f.exists()) {
+                return NanoHTTPD.newFixedLengthResponse(NanoHTTPD.Response.Status.NOT_FOUND,
+                        NanoHTTPD.MIME_PLAINTEXT, "file " + f + " doesn't exist");
+            }
+
+            return NanoHTTPD.newChunkedResponse(NanoHTTPD.Response.Status.OK,
+                    "application/json", new FileInputStream(f));
+        });
+    }
+}

TeamCode/util/LoggingUtil.java

@@ -0,0 +1,60 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import org.firstinspires.ftc.robotcore.internal.system.AppUtil;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Utility functions for log files.
+ */
+public class LoggingUtil {
+    public static final File ROAD_RUNNER_FOLDER =
+            new File(AppUtil.ROOT_FOLDER + "/RoadRunner/");
+
+    private static final long LOG_QUOTA = 25 * 1024 * 1024; // 25MB log quota for now
+
+    private static void buildLogList(List<File> logFiles, File dir) {
+        for (File file : dir.listFiles()) {
+            if (file.isDirectory()) {
+                buildLogList(logFiles, file);
+            } else {
+                logFiles.add(file);
+            }
+        }
+    }
+
+    private static void pruneLogsIfNecessary() {
+        List<File> logFiles = new ArrayList<>();
+        buildLogList(logFiles, ROAD_RUNNER_FOLDER);
+        Collections.sort(logFiles, (lhs, rhs) ->
+                Long.compare(lhs.lastModified(), rhs.lastModified()));
+
+        long dirSize = 0;
+        for (File file: logFiles) {
+            dirSize += file.length();
+        }
+
+        while (dirSize > LOG_QUOTA) {
+            if (logFiles.size() == 0) break;
+            File fileToRemove = logFiles.remove(0);
+            dirSize -= fileToRemove.length();
+            //noinspection ResultOfMethodCallIgnored
+            fileToRemove.delete();
+        }
+    }
+
+    /**
+     * Obtain a log file with the provided name
+     */
+    public static File getLogFile(String name) {
+        //noinspection ResultOfMethodCallIgnored
+        ROAD_RUNNER_FOLDER.mkdirs();
+
+        pruneLogsIfNecessary();
+
+        return new File(ROAD_RUNNER_FOLDER, name);
+    }
+}

TeamCode/util/LynxModuleUtil.java

@@ -0,0 +1,124 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import com.qualcomm.hardware.lynx.LynxModule;
+import com.qualcomm.robotcore.hardware.HardwareMap;
+
+import org.firstinspires.ftc.robotcore.internal.system.Misc;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Collection of utilites for interacting with Lynx modules.
+ */
+public class LynxModuleUtil {
+
+    private static final LynxFirmwareVersion MIN_VERSION = new LynxFirmwareVersion(1, 8, 2);
+
+    /**
+     * Parsed representation of a Lynx module firmware version.
+     */
+    public static class LynxFirmwareVersion implements Comparable<LynxFirmwareVersion> {
+        public final int major;
+        public final int minor;
+        public final int eng;
+
+        public LynxFirmwareVersion(int major, int minor, int eng) {
+            this.major = major;
+            this.minor = minor;
+            this.eng = eng;
+        }
+
+        @Override
+        public boolean equals(Object other) {
+            if (other instanceof LynxFirmwareVersion) {
+                LynxFirmwareVersion otherVersion = (LynxFirmwareVersion) other;
+                return major == otherVersion.major && minor == otherVersion.minor &&
+                        eng == otherVersion.eng;
+            } else {
+                return false;
+            }
+        }
+
+        @Override
+        public int compareTo(LynxFirmwareVersion other) {
+            int majorComp = Integer.compare(major, other.major);
+            if (majorComp == 0) {
+                int minorComp = Integer.compare(minor, other.minor);
+                if (minorComp == 0) {
+                    return Integer.compare(eng, other.eng);
+                } else {
+                    return minorComp;
+                }
+            } else {
+                return majorComp;
+            }
+        }
+
+        @Override
+        public String toString() {
+            return Misc.formatInvariant("%d.%d.%d", major, minor, eng);
+        }
+    }
+
+    /**
+     * Retrieve and parse Lynx module firmware version.
+     * @param module Lynx module
+     * @return parsed firmware version
+     */
+    public static LynxFirmwareVersion getFirmwareVersion(LynxModule module) {
+        String versionString = module.getNullableFirmwareVersionString();
+        if (versionString == null) {
+            return null;
+        }
+
+        String[] parts = versionString.split("[ :,]+");
+        try {
+            // note: for now, we ignore the hardware entry
+            return new LynxFirmwareVersion(
+                    Integer.parseInt(parts[3]),
+                    Integer.parseInt(parts[5]),
+                    Integer.parseInt(parts[7])
+            );
+        } catch (NumberFormatException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Exception indicating an outdated Lynx firmware version.
+     */
+    public static class LynxFirmwareVersionException extends RuntimeException {
+        public LynxFirmwareVersionException(String detailMessage) {
+            super(detailMessage);
+        }
+    }
+
+    /**
+     * Ensure all of the Lynx modules attached to the robot satisfy the minimum requirement.
+     * @param hardwareMap hardware map containing Lynx modules
+     */
+    public static void ensureMinimumFirmwareVersion(HardwareMap hardwareMap) {
+        Map<String, LynxFirmwareVersion> outdatedModules = new HashMap<>();
+        for (LynxModule module : hardwareMap.getAll(LynxModule.class)) {
+            LynxFirmwareVersion version = getFirmwareVersion(module);
+            if (version == null || version.compareTo(MIN_VERSION) < 0) {
+                for (String name : hardwareMap.getNamesOf(module)) {
+                    outdatedModules.put(name, version);
+                }
+            }
+        }
+        if (outdatedModules.size() > 0) {
+            StringBuilder msgBuilder = new StringBuilder();
+            msgBuilder.append("One or more of the attached Lynx modules has outdated firmware\n");
+            msgBuilder.append(Misc.formatInvariant("Mandatory minimum firmware version for Road Runner: %s\n",
+                    MIN_VERSION.toString()));
+            for (Map.Entry<String, LynxFirmwareVersion> entry : outdatedModules.entrySet()) {
+                msgBuilder.append(Misc.formatInvariant(
+                        "\t%s: %s\n", entry.getKey(),
+                        entry.getValue() == null ? "Unknown" : entry.getValue().toString()));
+            }
+            throw new LynxFirmwareVersionException(msgBuilder.toString());
+        }
+    }
+}

TeamCode/util/RegressionUtil.java

@@ -0,0 +1,156 @@
+package org.firstinspires.ftc.teamcode.util;
+
+import androidx.annotation.Nullable;
+
+import com.acmerobotics.roadrunner.kinematics.Kinematics;
+
+import org.apache.commons.math3.stat.regression.SimpleRegression;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Various regression utilities.
+ */
+public class RegressionUtil {
+
+    /**
+     * Feedforward parameter estimates from the ramp regression and additional summary statistics
+     */
+    public static class RampResult {
+        public final double kV, kStatic, rSquare;
+
+        public RampResult(double kV, double kStatic, double rSquare) {
+            this.kV = kV;
+            this.kStatic = kStatic;
+            this.rSquare = rSquare;
+        }
+    }
+
+    /**
+     * Feedforward parameter estimates from the ramp regression and additional summary statistics
+     */
+    public static class AccelResult {
+        public final double kA, rSquare;
+
+        public AccelResult(double kA, double rSquare) {
+            this.kA = kA;
+            this.rSquare = rSquare;
+        }
+    }
+
+    /**
+     * Numerically compute dy/dx from the given x and y values. The returned list is padded to match
+     * the length of the original sequences.
+     *
+     * @param x x-values
+     * @param y y-values
+     * @return derivative values
+     */
+    private static List<Double> numericalDerivative(List<Double> x, List<Double> y) {
+        List<Double> deriv = new ArrayList<>(x.size());
+        for (int i = 1; i < x.size() - 1; i++) {
+            deriv.add(
+                    (y.get(i + 1) - y.get(i - 1)) /
+                    (x.get(i + 1) - x.get(i - 1))
+            );
+        }
+        // copy endpoints to pad output
+        deriv.add(0, deriv.get(0));
+        deriv.add(deriv.get(deriv.size() - 1));
+        return deriv;
+    }
+
+    /**
+     * Run regression to compute velocity and static feedforward from ramp test data.
+     *
+     * Here's the general procedure for gathering the requisite data:
+     *   1. Slowly ramp the motor power/voltage and record encoder values along the way.
+     *   2. Run a linear regression on the encoder velocity vs. motor power plot to obtain a slope
+     *      (kV) and an optional intercept (kStatic).
+     *
+     * @param timeSamples time samples
+     * @param positionSamples position samples
+     * @param powerSamples power samples
+     * @param fitStatic fit kStatic
+     * @param file log file
+     */
+    public static RampResult fitRampData(List<Double> timeSamples, List<Double> positionSamples,
+                                         List<Double> powerSamples, boolean fitStatic,
+                                         @Nullable File file) {
+        if (file != null) {
+            try (PrintWriter pw = new PrintWriter(file)) {
+                pw.println("time,position,power");
+                for (int i = 0; i < timeSamples.size(); i++) {
+                    double time = timeSamples.get(i);
+                    double pos = positionSamples.get(i);
+                    double power = powerSamples.get(i);
+                    pw.println(time + "," + pos + "," + power);
+                }
+            } catch (FileNotFoundException e) {
+                // ignore
+            }
+        }
+
+        List<Double> velSamples = numericalDerivative(timeSamples, positionSamples);
+
+        SimpleRegression rampReg = new SimpleRegression(fitStatic);
+        for (int i = 0; i < timeSamples.size(); i++) {
+            double vel = velSamples.get(i);
+            double power = powerSamples.get(i);
+
+            rampReg.addData(vel, power);
+        }
+
+        return new RampResult(Math.abs(rampReg.getSlope()), Math.abs(rampReg.getIntercept()),
+                              rampReg.getRSquare());
+    }
+
+    /**
+     * Run regression to compute acceleration feedforward.
+     *
+     * @param timeSamples time samples
+     * @param positionSamples position samples
+     * @param powerSamples power samples
+     * @param rampResult ramp result
+     * @param file log file
+     */
+    public static AccelResult fitAccelData(List<Double> timeSamples, List<Double> positionSamples,
+                                           List<Double> powerSamples, RampResult rampResult,
+                                           @Nullable File file) {
+        if (file != null) {
+            try (PrintWriter pw = new PrintWriter(file)) {
+                pw.println("time,position,power");
+                for (int i = 0; i < timeSamples.size(); i++) {
+                    double time = timeSamples.get(i);
+                    double pos = positionSamples.get(i);
+                    double power = powerSamples.get(i);
+                    pw.println(time + "," + pos + "," + power);
+                }
+            } catch (FileNotFoundException e) {
+                // ignore
+            }
+        }
+
+        List<Double> velSamples = numericalDerivative(timeSamples, positionSamples);
+        List<Double> accelSamples = numericalDerivative(timeSamples, velSamples);
+
+        SimpleRegression accelReg = new SimpleRegression(false);
+        for (int i = 0; i < timeSamples.size(); i++) {
+            double vel = velSamples.get(i);
+            double accel = accelSamples.get(i);
+            double power = powerSamples.get(i);
+
+            double powerFromVel = Kinematics.calculateMotorFeedforward(
+                    vel, 0.0, rampResult.kV, 0.0, rampResult.kStatic);
+            double powerFromAccel = power - powerFromVel;
+
+            accelReg.addData(accel, powerFromAccel);
+        }
+
+        return new AccelResult(Math.abs(accelReg.getSlope()), accelReg.getRSquare());
+    }
+}