Coasting Problems

[Matt_4505]

I'm using the Java Library. My inputs are from the .getY() values of the joysticks. The motors are being controlled through: tankDrive(leftJoystickValue, rightJoystickValue). I have the values from the Joystick.getY() being fed to the dashboard to view them. They always seem to read between .1<->.3 when the joystick is released. Should I be using the route of the .getY() value to drive the robot?

[BigJ]

Can you elaborate more by what you mean by this:

for which I've set up some wiggle room with a pair of if statements.

To me that sounds like you're trying to set a deadzone, but I'm not sure.

[Matt_4505]

Originally Posted by BigJ

Can you elaborate more by what you mean by this:



To me that sounds like you're trying to set a deadzone, but I'm not sure.

Yep, that code is to set a deadzone, although since I have to keep increasing it's size, I'm losing a lot of mobility.

It might be an issue with zeroing the motor controllers, although, it works fine with Labview.

Heres the code:

public class DriveControl {
double leftJoystickValue = 0;
double rightJoystickValue = 0;

/**
* Controls the Joystick Read-in.
* Reads the joystick values and directs values to the motors.
*/
public void driveRobot() {

if(Math.abs(Hardware.leftJoystick.getY()) > .25){
leftJoystickValue = Hardware.leftJoystick.getY();
}
if(Math.abs(Hardware.rightJoystick.getY()) > .25){
rightJoystickValue = Hardware.rightJoystick.getY();
}

SmartDashboard.putNumber("leftJoystickValue", leftJoystickValue);
SmartDashboard.putNumber("righttJoystickValue", rightJoystickValue);

//decrease values by 3/4 for each trigger pressed
if (Hardware.leftJoystick.getRawButton(1)) {
leftJoystickValue = leftJoystickValue * (.75);
rightJoystickValue = leftJoystickValue * (.75);
}
SmartDashboard.putBoolean("leftJoystickTrigger Pressed", Hardware.leftJoystick.getRawButton(1));
//reduces values even more
if (Hardware.rightJoystick.getRawButton(1)) {
leftJoystickValue = leftJoystickValue * (.75);
rightJoystickValue = leftJoystickValue * (.75);
}
SmartDashboard.putBoolean("rigbhtJoystickTrigger Pressed", Hardware.rightJoystick.getRawButton(1)); //sends signal to bot with the adjusted drive values

Hardware.chassis.tankDrive(leftJoystickValue, rightJoystickValue);
}

[Joe Ross]

Originally Posted by Matt_4505

public class DriveControl {
    double leftJoystickValue = 0;
    double rightJoystickValue = 0;
    
    /**
     * Controls the Joystick Read-in.
     * Reads the joystick values and directs values to the motors.
     */
    public void driveRobot() {

        if(Math.abs(Hardware.leftJoystick.getY()) > .25){
            leftJoystickValue = Hardware.leftJoystick.getY();
        }
        if(Math.abs(Hardware.rightJoystick.getY()) > .25){
            rightJoystickValue = Hardware.rightJoystick.getY();
        }

This code will make the speed controllers run at about 0.25 when the joystick ramps down.

Imagine the following scenario

joystick output
1        1
0.75     0.75
0.5      0.5
0.3      0.3
0.26     0.26
0.25     0.25
0.1      0.25
0.0      0.25

You need to explicitly set the value back to 0 when it is <= 0.25. The initialize to 0 at the top only occurs once.

[Matt_4505]

Thank you for your help! I added to the code so the values are zeroed. I'm amazed that I missed that earlier.

[ekapalka]

Just for future reference, my favourite deadzone code looks something like this:

float deadZ (float val) {
	return val > 0.6 || val < -0.6? val: 0;
}

Then you would simply say something like 'tankDrive(deadZ(leftStick), deadZ(rightStick));'
To me this is the most aesthetically pleasing. But to each his own :P One thing I noticed that would also make it look better (my apologies, I'm really picky about these things) would be to assign 'Hardware.leftJoystick.getRawButton(1)' to a boolean somewhere in the beginning of your code so that you don't have to type that mess every time you need to check it. You could also make a similar method to the one above that takes your boolean as an input as well as a joystick value and clean up the code even more (there's currently a lot of code involved in just getting it to drive). Just my $0.02 :P Take it with a grain of salt

[Matt_4505]

Thanks, I will definitely give those a try.