PS4 Controller?

Technical Programming
1

We are trying to use a PS4 controller to drive our robot but we are getting weird values from it.

2

What sort of weird values? What code are you using to get those values?

3

We are just using the WPIlib joystick code to get them. When the joystick is not pressed it bounces from 0.1-0.2.

4

This is not uncommon for many controllers. You need to program in a deadband - perhaps a wrapper class for the controller could implement this - to ignore values below the threshold (and perhaps scale the joystick output across the rest of the range). This is an issue common to several controllers: PS4, Xbox 360, etc.

5

@Galen6790

I just created a class DeadBand and put this in it. Which I’m sure I copied from CD. My Java Kung Fo is not strong, but getting better.

package frc.robot;
/**

  • A class to try to tone down the deadband in the joysticks to make

  • the robot less jumpy.

  • Takes in the axis from a joystick, checks if it’s under the deadBandrate

  • set the axis to 0.0 and return it.
    */
    public class DeadBand {

    public static final double deadBandrate = 0.15; //<-- Change this up and down to a setting that works best for your controller.

    public double SmoothAxis(double joyStickAxis){

    if (Math.abs(joyStickAxis) < deadBandrate) {
    joyStickAxis = 0.0;
    }
    else {
    if (joyStickAxis>0.0) {
    joyStickAxis = (joyStickAxis - deadBandrate) / (1.0 - deadBandrate);
    }
    else {
    joyStickAxis = (joyStickAxis - -deadBandrate) / (1.0 - deadBandrate);
    }// ******** end if > *******
    }// ****** end if <

    return joyStickAxis;

    } // *********************** end of SmoothAxis **********************

}// ************************ end of Class DeadBand *********************

Then in my Teleop I have

m_robotDrive.driveCartesian(m_stick.SmoothAxis(m_controllerDriver.getRawAxis(1)), 
                            m_stick.SmoothAxis(m_controllerDriver.getRawAxis(0)), 
                            m_stick.SmoothAxis(m_controllerDriver.getRawAxis(4)));

Again, sorry for the bad Java. Hope this helps in someway, and you and your team have a great season.

-Russ

6