Programming - OnBot Java Overview

The OnBot Java version of the program is nearly identical to the Blocks version this year. Therefore the walkthrough for the Blocks version is applicable to the OnBot Java option.

Notable differences:

Some methods, also known as functions, have been reorganized for better clarity and readability. For example, the flywheel related methods are organized together.

For autonomous, the initRobot method found in the Blocks version is removed. The related information is called at the beginning when the variables or hardwareMap are first referenced.

Basic OnBot Java Code:

package org.firstinspires.ftc.teamcode;

import com.qualcomm.robotcore.eventloop.opmode.LinearOpMode;
import com.qualcomm.robotcore.eventloop.opmode.TeleOp;
import com.qualcomm.robotcore.hardware.CRServo;
import com.qualcomm.robotcore.hardware.DcMotor;
import com.qualcomm.robotcore.hardware.DcMotorEx;

@TeleOp
public class REVStarterBotTeleOpJava extends LinearOpMode {

  private DcMotor flywheel;
  private DcMotor coreHex;
  private DcMotor leftDrive;
  private CRServo servo;
  private DcMotor rightDrive;

    // Setting our velocity targets. These values are in ticks per second!
  private static final int bankVelocity = 1300;
  private static final int farVelocity = 1900;
  private static final int maxVelocity = 2200;

  @Override
  public void runOpMode() {
    flywheel = hardwareMap.get(DcMotor.class, "flywheel");
    coreHex = hardwareMap.get(DcMotor.class, "coreHex");
    leftDrive = hardwareMap.get(DcMotor.class, "leftDrive");
    servo = hardwareMap.get(CRServo.class, "servo");
    rightDrive = hardwareMap.get(DcMotor.class, "rightDrive");

    // Establishing the direction and mode for the motors
    flywheel.setMode(DcMotor.RunMode.RUN_USING_ENCODER);
    flywheel.setDirection(DcMotor.Direction.REVERSE);
    coreHex.setDirection(DcMotor.Direction.REVERSE);
    leftDrive.setDirection(DcMotor.Direction.REVERSE);
    //Ensures the servo is active and ready
    servo.setPower(0);
   
    waitForStart();
    if (opModeIsActive()) {
      while (opModeIsActive()) {
        // Calling our methods while the OpMode is running
        splitStickArcadeDrive();
        setFlywheelVelocity();
        manualCoreHexAndServoControl();
        telemetry.addData("Flywheel Velocity", ((DcMotorEx) flywheel).getVelocity());
        telemetry.addData("Flywheel Power", flywheel.getPower());
        telemetry.update();
      }
    }
  }

  /**
   * Controls for the drivetrain. The robot uses a split stick stlye arcade drive. 
   * Forward and back is on the left stick. Turning is on the right stick.
   */
  private void splitStickArcadeDrive() {
    float x;
    float y;

    x = gamepad1.right_stick_x;
    y = -gamepad1.left_stick_y;
    leftDrive.setPower(y - x);
    rightDrive.setPower(y + x);
  }
  
  /**
   * Manual control for the Core Hex powered feeder and the agitator servo in the hopper
   */
  private void manualCoreHexAndServoControl() {
    // Manual control for the Core Hex intake
    if (gamepad1.cross) {
      coreHex.setPower(0.5);
    } else if (gamepad1.triangle) {
      coreHex.setPower(-0.5);
    }
    // Manual control for the hopper's servo
    if (gamepad1.dpad_left) {
      servo.setPower(1);
    } else if (gamepad1.dpad_right) {
      servo.setPower(-1);
    }
  }
  
  //Flywheel Code
  /**
   * This if/else statement contains the controls for the flywheel, both manual and auto.
   * Circle and Square will spin up ONLY the flywheel to the target velocity set.
   * The bumpers will activate the flywheel, Core Hex feeder, and servo to cycle a series of balls.
   */
  private void setFlywheelVelocity() {
    if (gamepad1.options) {
      flywheel.setPower(-0.5);
    } else if (gamepad1.left_bumper) {
      farPowerAuto();
    } else if (gamepad1.right_bumper) {
      bankShotAuto();
    } else if (gamepad1.circle) {
      ((DcMotorEx) flywheel).setVelocity(bankVelocity);
    } else if (gamepad1.square) {
      ((DcMotorEx) flywheel).setVelocity(maxVelocity);
    } else {
      ((DcMotorEx) flywheel).setVelocity(0);
      coreHex.setPower(0);
      // The check below is in place to prevent stuttering with the servo. It checks if the servo is under manual control!
      if (!gamepad1.dpad_right && !gamepad1.dpad_left) {
        servo.setPower(0);
      }
    }
  }

  /**
   * The bank shot or near velocity is intended for launching balls touching or a few inches from the goal.
   * When running this function, the flywheel will spin up and the Core Hex will wait before balls can be fed.
   * The servo will spin until the bumper is released.
   */
  private void bankShotAuto() {
    ((DcMotorEx) flywheel).setVelocity(bankVelocity);
    servo.setPower(-1);
    if (((DcMotorEx) flywheel).getVelocity() >= bankVelocity - 50) {
      coreHex.setPower(1);
    } else {
      coreHex.setPower(0);
    }
  }

  /**
   * The far power velocity is intended for launching balls a few feet from the goal. It may require adjusting the deflector.
   * When running this function, the flywheel will spin up and the Core Hex will wait before balls can be fed.
   * The servo will spin until the bumper is released.
   */
  private void farPowerAuto() {
    ((DcMotorEx) flywheel).setVelocity(farVelocity);
    servo.setPower(-1);
    if (((DcMotorEx) flywheel).getVelocity() >= farVelocity - 100) {
      coreHex.setPower(1);
    } else {
      coreHex.setPower(0);
    }
  }

}

OnBot Java Code with Auto:

package org.firstinspires.ftc.teamcode;

import com.qualcomm.robotcore.eventloop.opmode.LinearOpMode;
import com.qualcomm.robotcore.eventloop.opmode.TeleOp;
import com.qualcomm.robotcore.hardware.CRServo;
import com.qualcomm.robotcore.hardware.DcMotor;
import com.qualcomm.robotcore.hardware.DcMotorEx;
import com.qualcomm.robotcore.util.ElapsedTime;

@TeleOp
public class REVStarterBotTeleOpAutoJava extends LinearOpMode {

  private DcMotor flywheel;
  private DcMotor coreHex;
  private DcMotor leftDrive;
  private CRServo servo;
  private DcMotor rightDrive;

  private static final int bankVelocity = 1300;
  private static final int farVelocity = 1900;
  private static final int maxVelocity = 2200;
  private static final String TELEOP = "TELEOP";
  private static final String AUTO_BLUE = "AUTO BLUE";
  private static final String AUTO_RED = " AUTO RED";
  private String operationSelected = TELEOP;
  private double WHEELS_INCHES_TO_TICKS = (28 * 5 * 3) / (3 * Math.PI);
  private ElapsedTime autoLaunchTimer = new ElapsedTime();
  private ElapsedTime autoDriveTimer = new ElapsedTime();

  @Override
  public void runOpMode() {
    flywheel = hardwareMap.get(DcMotor.class, "flywheel");
    coreHex = hardwareMap.get(DcMotor.class, "coreHex");
    leftDrive = hardwareMap.get(DcMotor.class, "leftDrive");
    servo = hardwareMap.get(CRServo.class, "servo");
    rightDrive = hardwareMap.get(DcMotor.class, "rightDrive");
    
  // Establishing the direction and mode for the motors
    flywheel.setMode(DcMotor.RunMode.RUN_USING_ENCODER);
    flywheel.setDirection(DcMotor.Direction.REVERSE);
    coreHex.setDirection(DcMotor.Direction.REVERSE);
    leftDrive.setDirection(DcMotor.Direction.REVERSE);
    //Ensures the servo is active and ready
    servo.setPower(0);

  //On initilization the Driver Station will prompt for which OpMode should be run - Auto Blue, Auto Red, or TeleOp
    while (opModeInInit()) {
      operationSelected = selectOperation(operationSelected, gamepad1.psWasPressed());
      telemetry.update();
    }
    waitForStart();
    if (operationSelected.equals(AUTO_BLUE)) {
      doAutoBlue();
    } else if (operationSelected.equals(AUTO_RED)) {
      doAutoRed();
    } else {
      doTeleOp();
    }
  }

  /**
   * If the PS/Home button is pressed, the robot will cycle through the OpMode options following the if/else statement here.
   * The telemetry readout to the Driver Station App will update to reflect which is currently selected for when "play" is pressed.
   */
  private String selectOperation(String state, boolean cycleNext) {
    if (cycleNext) {
      if (state.equals(TELEOP)) {
        state = AUTO_BLUE;
      } else if (state.equals(AUTO_BLUE)) {
        state = AUTO_RED;
      } else if (state.equals(AUTO_RED)) {
        state = TELEOP;
      } else {
        telemetry.addData("WARNING", "Unknown Operation State Reached - Restart Program");
      }
    }
    telemetry.addLine("Press Home Button to cycle options");
    telemetry.addData("CURRENT SELECTION", state);
    if (state.equals(AUTO_BLUE) || state.equals(AUTO_RED)) {
      telemetry.addLine("Please remember to enable the AUTO timer!");
    }
    telemetry.addLine("Press START to start your program");
    return state;
  }
  
  //TeleOp Code 
  
  /**
   * If TeleOp was selected or defaulted to, the following will be active upon pressing "play".
   */
  private void doTeleOp() {
    if (opModeIsActive()) {
      while (opModeIsActive()) {
        // Calling our methods while the OpMode is running
        splitStickArcadeDrive();
        setFlywheelVelocity();
        manualCoreHexAndServoControl();
        telemetry.addData("Flywheel Velocity", ((DcMotorEx) flywheel).getVelocity());
        telemetry.addData("Flywheel Power", flywheel.getPower());
        telemetry.update();
      }
    }
  }
  
    /**
   * Controls for the drivetrain. The robot uses a split stick stlye arcade drive. 
   * Forward and back is on the left stick. Turning is on the right stick.
   */
  private void splitStickArcadeDrive() {
    float X;
    float Y;

    X = gamepad1.right_stick_x;
    Y = -gamepad1.left_stick_y;
    leftDrive.setPower(Y - X);
    rightDrive.setPower(Y + X);
  }
  
    /**
   * Manual control for the Core Hex powered feeder and the agitator servo in the hopper
   */
  private void manualCoreHexAndServoControl() {
    // Manual control for the Core Hex intake
    if (gamepad1.cross) {
      coreHex.setPower(0.5);
    } else if (gamepad1.triangle) {
      coreHex.setPower(-0.5);
    }
    // Manual control for the hopper's servo
    if (gamepad1.dpad_left) {
      servo.setPower(1);
    } else if (gamepad1.dpad_right) {
      servo.setPower(-1);
    }
  }
  
    /**
   * This if/else statement contains the controls for the flywheel, both manual and auto.
   * Circle and Square will spin up ONLY the flywheel to the target velocity set.
   * The bumpers will activate the flywheel, Core Hex feeder, and servo to cycle a series of balls.
   */
  private void setFlywheelVelocity() {
    if (gamepad1.options) {
      flywheel.setPower(-0.5);
    } else if (gamepad1.left_bumper) {
      FAR_POWER_AUTO();
    } else if (gamepad1.right_bumper) {
      BANK_SHOT_AUTO();
    } else if (gamepad1.circle) {
      ((DcMotorEx) flywheel).setVelocity(bankVelocity);
    } else if (gamepad1.square) {
      ((DcMotorEx) flywheel).setVelocity(maxVelocity);
    } else {
      ((DcMotorEx) flywheel).setVelocity(0);
      coreHex.setPower(0);
      // The check below is in place to prevent stuttering with the servo. It checks if the servo is under manual control!
      if (!gamepad1.dpad_right && !gamepad1.dpad_left) {
        servo.setPower(0);
      }
    }
  }

//Automatic Flywheel controls used in Auto and TeleOp 

  /**
   * The bank shot or near velocity is intended for launching balls touching or a few inches from the goal.
   * When running this function, the flywheel will spin up and the Core Hex will wait before balls can be fed.
   * The servo will spin until the bumper is released.
   */
  private void BANK_SHOT_AUTO() {
    ((DcMotorEx) flywheel).setVelocity(bankVelocity);
    servo.setPower(-1);
    if (((DcMotorEx) flywheel).getVelocity() >= bankVelocity - 100) {
      coreHex.setPower(1);
    } else {
      coreHex.setPower(0);
    }
  }

  /**
   * The far power velocity is intended for launching balls a few feet from the goal. It may require adjusting the deflector.
   * When running this function, the flywheel will spin up and the Core Hex will wait before balls can be fed.
   * The servo will spin until the bumper is released.
   */
  private void FAR_POWER_AUTO() {
    ((DcMotorEx) flywheel).setVelocity(farVelocity);
    servo.setPower(-1);
    if (((DcMotorEx) flywheel).getVelocity() >= farVelocity - 100) {
      coreHex.setPower(1);
    } else {
      coreHex.setPower(0);
    }
  }

//Autonomous Code
//For autonomous, the robot will launch the pre-loaded 3 balls then back away from the goal, turn, and back up off the launch line.
  
  /**
   * For autonomous, the robot is using a timer and encoders on the drivetrain to move away from the target. 
   * This method contains the math to be used with the inputted distance for the encoders, resets the elapsed timer, and
   * provides a check for it to run so long as the motors are busy and the timer has not run out. 
   */
  private void autoDrive(double speed, int leftDistanceInch, int rightDistanceInch, int timeout_ms) {
    autoDriveTimer.reset();
    leftDrive.setTargetPosition((int) (leftDrive.getCurrentPosition() + leftDistanceInch * WHEELS_INCHES_TO_TICKS));
    rightDrive.setTargetPosition((int) (rightDrive.getCurrentPosition() + rightDistanceInch * WHEELS_INCHES_TO_TICKS));
    leftDrive.setMode(DcMotor.RunMode.RUN_TO_POSITION);
    rightDrive.setMode(DcMotor.RunMode.RUN_TO_POSITION);
    leftDrive.setPower(Math.abs(speed));
    rightDrive.setPower(Math.abs(speed));
    while (opModeIsActive() && (leftDrive.isBusy() || rightDrive.isBusy()) && autoDriveTimer.milliseconds() < timeout_ms) {
      idle();
    }
    leftDrive.setPower(0);
    rightDrive.setPower(0);
    leftDrive.setMode(DcMotor.RunMode.RUN_WITHOUT_ENCODER);
    rightDrive.setMode(DcMotor.RunMode.RUN_WITHOUT_ENCODER);
  }

  /**
   * Blue Alliance Autonomous
   * The robot will fire the pre-loaded balls until the 10 second timer ends. 
   * Then it will back away from the goal and off the launch line.
   */
  private void doAutoBlue() {
    if (opModeIsActive()) {
      telemetry.addData("RUNNING OPMODE", operationSelected);
      telemetry.update();
      // Fire balls
      autoLaunchTimer.reset();
      while (opModeIsActive() && autoLaunchTimer.milliseconds() < 10000) {
        BANK_SHOT_AUTO();
        telemetry.addData("Launcher Countdown", autoLaunchTimer.seconds());
        telemetry.update();
      }
      ((DcMotorEx) flywheel).setVelocity(0);
      coreHex.setPower(0);
      servo.setPower(0);
      // Back Up
      autoDrive(0.5, -12, -12, 5000);
      // Turn
      autoDrive(0.5, -8, 8, 5000);
      // Drive off Line
      autoDrive(1, -50, -50, 5000);
    }
  }

  /**
   * Red Alliance Autonomous
   * The robot will fire the pre-loaded balls until the 10 second timer ends. 
   * Then it will back away from the goal and off the launch line.
   */
  private void doAutoRed() {
    if (opModeIsActive()) {
      telemetry.addData("RUNNING OPMODE", operationSelected);
      telemetry.update();
      // Fire balls
      autoLaunchTimer.reset();
      while (opModeIsActive() && autoLaunchTimer.milliseconds() < 10000) {
        BANK_SHOT_AUTO();
        telemetry.addData("Launcher Countdown", autoLaunchTimer.seconds());
        telemetry.update();
      }
      ((DcMotorEx) flywheel).setVelocity(0);
      coreHex.setPower(0);
      servo.setPower(0);
      // Back Up
      autoDrive(0.5, -12, -12, 5000);
      // Turn
      autoDrive(0.5, 8, -8, 5000);
      // Drive off Line
      autoDrive(1, -50, -50, 5000);
    }
  }
}