Java Iterative-Robot: Toggle Buttons?

[BL0X3R]

Originally Posted by Fauge7

suggestion #1: dont use iterative, Java is an object oriented programming for what it is meant for, objects!

I hope you aren't suggesting that this team completely rewrites their robot code to work in a new style a few weeks before the competition. "Don't use iterative" is a pretty overgeneralized statement to make: Plenty of teams use it, some to great success.
The main difference between Iterative and Command based besides structure and style is that Iterative is continuous and periodic, while Command based is built around being asynchronous. While it is also true that the Command based model does use more of the features of object oriented programming, that does not necessarily always make it better in this environment.

Originally Posted by Fauge7

suggestion #2: post your code so we might be able to help

This. Even if you can only post the section that you are having trouble with, any amount of context can help us find a solution.

Originally Posted by Fauge7

boolean buttonToggle = false;
if (button.isPressed()) {
  buttonToggle = !buttonToggle;
}

//code for using it:

if (buttonToggle) {
motor.setSpeed(someSpeed);
}

This would work for a command based robot, but because of the periodic nature of Iterative robot, this code gets run about 50 times a second. Therefore, if the driver holds the button for more than 20ms, the toggle variable will flip more than once.
One solution is to only flip the variable on the rising edge of the button press - to check if the button is pressed, but was not pressed earlier. Example below.

boolean buttonToggle = false;
boolean buttonLast = false;

public void runToggle(boolean buttonValue){
     if(buttonValue && !buttonLast)
          buttonToggle = !buttonToggle;     

     buttonLast = buttonValue;

     if(buttonToggle)
          motor.setSpeed(someSpeed)
}

[rrossbach]

Our team developed a short extension of the Joystick class implementing a couple of useful methods for cases like this.

One of those is a "getToggleButton(int buttonNumber)" that you can use just like getRawButton() in Joystick, the difference being that the return value of the method starts off false and alternates between true and false with each press of the button.

The code is up in our github repo, here's a link to the specific class (robovikingStick)

Hope that helps!

- Ron
Team #2607 controls mentor

[lethc]

We use 254's Latch class.

Github Link

Their code has been a huge resource for our team.

[Fauge7]

Originally Posted by BL0X3R

I hope you aren't suggesting that this team completely rewrites their robot code to work in a new style a few weeks before the competition. "Don't use iterative" is a pretty overgeneralized statement to make: Plenty of teams use it, some to great success.
The main difference between Iterative and Command based besides structure and style is that Iterative is continuous and periodic, while Command based is built around being asynchronous. While it is also true that the Command based model does use more of the features of object oriented programming, that does not necessarily always make it better in this environment.

actually command based is also periodic, each subsystem runs the command about every 20ms...but as for a code rewrite it wouldn't necessarily be wise but it wouldn't be impossible.

Originally Posted by BL0X3R

This would work for a command based robot, but because of the periodic nature of Iterative robot, this code gets run about 50 times a second. Therefore, if the driver holds the button for more than 20ms, the toggle variable will flip more than once.
One solution is to only flip the variable on the rising edge of the button press - to check if the button is pressed, but was not pressed earlier. Example below.

well, the toggle can work both ways on down and up. IF it runs for 20ms loops and the user holds the button down for 100ms that is 5 loops it runs through before the code reacts, so I would suggest making it on the downstroke instead of the upstroke