README.md

FRC Project 03

In this project, you are going to select a partner to be able to work with, and both of you will be creating an algorithm that does the following:

• You must program a drivetrain that moves forward or backward straight depending on the value of the leftJoySticky variable in the Joystick file. To drive straight, you are going to create a program that can make the robot go straight by using encoder values.

Using Joystick values

In the FRC Project_01, we learned that you could set a motor to a speed from -1 to 1. Fortunately, this is how the Joystick works too. Analog joysticks have values from -1 to 1, and buttons have values of true or false. There is also something called a dead-zone we add to analog joystick values. The purpose of this is to avoid values like .01, .12, etc. For instance, the value of an analog joystick is never technically 0. They are just close to 0. Since we don't want the robot to move unless the joystick has a value of above .15, we make the dead-zone .15. This means that if the joystick value is any less than .15 or greater than -.15, we set the value of the joystick to 0.

import edu.wpi.first.wpilibj.Joystick;
public class Joysticks 
{
	//The Joy stick Object
	public Joystick mainController = new Joystick(0);
	
	//Joy stick Variables
	public static boolean rightBumper;
	public static boolean leftBumper;
	public static boolean buttonA;
	public static boolean buttonB;
	public static boolean buttonX;
	public static boolean buttonY;
	public static double rightTrigger;
	public static double leftTrigger;	
	public static double leftJoySticky;
	public static double rightJoyStickx;
	public static double rightJoySticky;
	public static double leftJoyStickx;
	
	//assigning values to variables through this function
	public void updateMainController()
	{
		rightBumper = mainController.getRawButton(6);
		leftBumper = mainController.getRawButton(5);
		leftTrigger = fixController(mainController.getRawAxis(2));
		buttonA = mainController.getRawButton(1);
		buttonB = mainController.getRawButton(2);
		rightTrigger = fixController(mainController.getRawAxis(3));
		buttonY = mainController.getRawButton(4);
		leftJoySticky = fixController(-mainController.getRawAxis(1));
		leftJoyStickx = fixController(mainController.getRawAxis(0));
		rightJoyStickx = fixController(mainController.getRawAxis(4));
		rightJoySticky = fixController(mainController.getRawAxis(5));
		
	}
	
	//Dead-zone function
	public double fixController(double joyStickValue)
	{
		if(joyStickValue < .15 && joyStickValue > -.15)
		{
			return 0;
		}
		else
		{
			return joyStickValue;
		}
	}
}

For the robot motors to move in the direction to the value of the leftJoySticky variable, the following code would work (Assuming you have created the Spark objects in the Motors file, and that the leftJoySticky variable in the Joysticks class is static):

public void teleopPeriodic() 
{
	Motors.leftMotor.set(Joysticks.leftJoySticky);
	Motors.rightMotor.set(-Joysticks.leftJoySticky);
}

Here is a picture of the Joystick:

The way we would implement this program by using the Joystick is by using the function you created in FRC Project_02, and instead of using the speed variable to determine speed, you would use the leftJoySticky variable from the Joystick file.

Here is a list of clues/changes you would have to make from your previous exercise:

• A slight change in your algorithm because it has to be now able to travel backward straightly too.
• Since the program will be tele-operated, there will be no distance variable, unlike the previous project.
• You would have to reset encoders whenever the value ofleftJoySticky variable becomes 0.

Good luck on the project!