SmartDashboard output help

Technical Java
1

Hi, I am having an error whenever I run certain code on the roborio.
When i commented out all of the code in method driveForward() except the variable declarations, the console doesn’t output any errors, but when I uncomment and include leftEncoder.reset() and rightEncoder.reset(), I get an error that disables my robot. Any help is appreciated.

This is the code I am running:

package org.usfirst.frc.team5242.robot;

import edu.wpi.first.wpilibj.AnalogInput;
import edu.wpi.first.wpilibj.BuiltInAccelerometer;
import edu.wpi.first.wpilibj.Encoder;
import edu.wpi.first.wpilibj.SampleRobot;
import edu.wpi.first.wpilibj.Timer;
import edu.wpi.first.wpilibj.Joystick;
import edu.wpi.first.wpilibj.RobotDrive;
import edu.wpi.first.wpilibj.Victor;
import edu.wpi.first.wpilibj.interfaces.Accelerometer;
import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;

/**

  • This is a sample program to demonstrate the use of a soft potentiometer and

  • proportional control to reach and maintain position setpoints on an elevator

  • mechanism. A joystick button is used to switch elevator setpoints.

  • WARNING: While it may look like a good choice to use for your code if you’re

  • inexperienced, don’t. Unless you know what you are doing, complex code will

  • be much more difficult under this system. Use IterativeRobot or Command-Based

  • instead if you’re new.
    */
    public class Robot extends SampleRobot {
    //Drive Objects
    BuiltInAccelerometer accel;
    RobotDrive drive;
    Joystick stick;
    Encoder leftEncoder;
    Encoder rightEncoder;
    Accelerometer accelerometer;

    final int kPotChannel = 1; // analog input pin
    final int kMotorChannel = 7; // PWM channel
    final int kJoystickChannel = 0; // usb number in DriverStation
    final int kButtonNumber = 4; // joystick button

    final double kSetPoints] = { 1.0, 2.6, 4.3 }; // bottom, middle, and top
    // elevator setpoints

    final double kP = 1.0; // proportional speed constant
    double motorSpeed;
    double currentPosition; // sensor voltage reading corresponding to current
    // elevator position

    // make objects for the potentiometer, elevator motor controller, and
    // joystick
    AnalogInput potentiometer = new AnalogInput(kPotChannel);
    Victor elevatorMotor = new Victor(kMotorChannel);
    Joystick joystick = new Joystick(kJoystickChannel);

    public Robot() {
    }

    public void driveForward2(float distance, float speed)
    {

    }

    public void driveForward(float distance, float speed)
    {
    int pulsesPerRev = 1024;
    double inchesPerRev = 6.0 * 3.141;
    double currentSpeed;
    double currentDistance;
    double acceleration;
    double deceleration;
    double driveDelay;

     currentSpeed = 0.0;
 currentDistance = 0.0;
 acceleration = 0.01;
 deceleration = 0.02;
 driveDelay = 0.01;

 

 //rightEncoder.reset();
 //leftEncoder.reset();

 rightEncoder.setDistancePerPulse(inchesPerRev / pulsesPerRev);
 
 
 /*while(currentDistance < distance)
 {
 	SmartDashboard.putNumber("Distance", currentDistance);
 	if (currentSpeed < speed)
 	{
 		currentSpeed = currentSpeed + acceleration;
 	}
 	//drive.tankDrive(currentSpeed, currentSpeed);
 	drive.tankDrive(0, 0);
 	Timer.delay(driveDelay);
 	currentDistance = (rightEncoder.getDistance() + leftEncoder.getDistance()) / 2;
 }
 
 while (currentSpeed > 0)
 {
 	currentSpeed = currentSpeed - deceleration;
 	if (currentSpeed < 0.0)
 		currentSpeed = 0.0;
 	drive.tankDrive(currentSpeed, currentSpeed);
 	Timer.delay(driveDelay);
 }
 */

    }

    /**

    • Runs during autonomous.
      */
      @Override
      public void autonomous() {
      //drive.setSafetyEnabled(false);
      SmartDashboard.putNumber(“start go”, 1);
      driveForward((float) 24.0,(float) 5.0);
      SmartDashboard.putNumber(“stop”, 5);
      //drive.setSafetyEnabled(true);
      }

    /**

    • Moves elevator to a selectable setpoint that can be changed by pressing a

    • button on the joystick. Proportional control is used to reach and

    • maintain the desired setpoint by obtaining values from the potentiometer

    • and comparing them to the setpoint value.
      */
      @Override
      public void operatorControl() {
      boolean buttonState;
      boolean prevButtonState = false;

      int index = 0; // setpoint array index
      double currentSetpoint; // holds desired setpoint
      currentSetpoint = kSetPoints[0]; // set to first setpoint

      while (isOperatorControl() && isEnabled()) {
      buttonState = joystick.getRawButton(kButtonNumber); // check if
      // button is
      // pressed

       // if button has been pressed and released once
 if (buttonState && !prevButtonState) {
 	index = (index + 1) % kSetPoints.length; // increment set point,
 												// reset if at end
 												// of
 												// array
 	currentSetpoint = kSetPoints[index]; // set setpoint
 }
 prevButtonState = buttonState; // record previous button state

 currentPosition = potentiometer.getAverageVoltage(); // get position
 														// value
 motorSpeed = (currentPosition - currentSetpoint) * kP; // convert
 														// position
 														// error
 														// to
 														// speed
 elevatorMotor.set(motorSpeed); // drive elevator motor

      }
      }

    /**

    • Runs during test mode
      */
      @Override
      public void test() {
      }
      }
2

Do you ever initialize the encoder objects?
For example:
leftEncoder = new Encoder(0, 1, false, Encoder.EncodingType.k4X);

http://first.wpi.edu/FRC/roborio/release/docs/java/edu/wpi/first/wpilibj/Encoder.html

Also for future reference, it would be helpful to post the entire error you get in addition to your code