TimedBase Robot Code Simulation Error

Technical Java
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1

Hello guys. I’m using TimedBase template and I tried to make a cleaner code so that I created some files under the “java/frc/robot” with the “.java”. At the end I finished organising all the parts and when I clicked build, it builded it without any error. However when I tried to simulate robot code in order to test some methods. It gives this error:
Error at frc.robot.Vision.(Vision.java:30): Unhandled exception instantiating robot frc.robot.Vision java.lang.NullPointerException
at frc.robot.Vision.(Vision.java:30)
at frc.robot.Robot.(Robot.java:35)
at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:322)
at edu.wpi.first.wpilibj.RobotBase.lambda$startRobot$0(RobotBase.java:443)

I checked if there was any syntax error but I couldn’t find any. So what should I do? Or can’t I create other classes with “Robot.java”? Thank you in advance.

Classes
Classes792×1920 31.6 KB

2

In Vision.java, you are trying to use an object without first having created the object. The problem is on line 30. That’s the best that I can say without seeing your code.

3

For example this is the code in the Vision.java file:
package frc.robot;

import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;

import edu.wpi.first.networktables.NetworkTable;

import edu.wpi.first.networktables.NetworkTableEntry;

import edu.wpi.first.networktables.NetworkTableInstance;

import edu.wpi.first.math.controller.PIDController;

import edu.wpi.first.math.util.Units;

import org.photonvision.PhotonCamera;

import org.photonvision.PhotonUtils;

import org.photonvision.targeting.PhotonTrackedTarget;

public class Vision {

MotorControl motorControl = new MotorControl();

final double CAMERA_HEIGHT_METERS = Units.inchesToMeters(24);

final double TARGET_HEIGHT_METERS = Units.feetToMeters(5);

final double CAMERA_PITCH_RADIANS = Units.degreesToRadians(0);

final double GOAL_RANGE_METERS = Units.feetToMeters(3);

final double LINEAR_P = 0.1;

final double LINEAR_D = 0.0;

PIDController forwardController = new PIDController(LINEAR_P, 0, LINEAR_D);

final double ANGULAR_P = 0.1;

final double ANGULAR_D = 0.0;

PIDController turnController = new PIDController(ANGULAR_P, 0, ANGULAR_D);

NetworkTableInstance mainTable = NetworkTableInstance.create();

NetworkTable RootTable;

double targetarea = RootTable.getEntry(“targetArea”).getDouble(0.0d);

double yaw = RootTable.getEntry(“targetYaw”).getDouble(0.0d);

double pitch = RootTable.getEntry(“targetPitch”).getDouble(0.0d);

//PhotonCamera camera;

//NetworkTables

//public static NetworkTable sycavision = NetworkTable.getTable(“Vision”);

public void Hizala_OP(){

    double xloc = RootTable.getEntry("targetYaw").getDouble(0.0d); //x ekseni

    //double yloc = RootTable.getEntry("targetPitch").getDouble(0.0d); // y ekseni

    double deneme = 0;

    if((xloc < 3 && xloc > 0) || (xloc >= -3 && xloc < 0)){

      motorControl.Stop();

      deneme = 1;

    }

    else if (xloc > 3){

      motorControl.Right(0.2);

      deneme = 2;

    }

    else if (xloc < -3){

      motorControl.Left(0.2);

      deneme = 3;

    }

    SmartDashboard.putNumber("Try", deneme);

  }

}

However when I put Vision class at the comment line at the Robot.java file and build it, it gives another error:
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)
at frc.robot.Robot.(Robot.java:36)
at frc.robot.Autonomous.(Autonomous.java:4)

Error at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:336): The robot program quit unexpectedly. This is usually due to a code error.
The above stacktrace can help determine where the error occurred.
See https://wpilib.org/stacktrace for more information.

Error at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:342): Could not instantiate robot edu.wpi.first.wpilibj.RobotBase!

4

Hmm. You would likewise have to post your Autonomous.java code, where there appears to be a problem on line 4. It almost looks like your Autonomous code is trying to create a Robot object, which is trying to create An Autonomous object, which… until you run out of memory.

5

You declare RootTable, but don’t initialize it. Then on the next line, you try to call RootTable.getEntry(...) which throws a NullPointerException because RootTable is null (uninitialized)

Be sure to read and understand this: https://docs.wpilib.org/en/stable/docs/software/basic-programming/reading-stacktraces.html

6

Guys I solved it thank you. Like you said I didn’t entirely passed the code correctly so that there were some mistakes that blocks the code to work. And also I guess I can’t create Robot class object at another classes like in Vision.java because of it is a part of TimedBase ? However I’m not sure. But in the end it solved thanks

7

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