Command Based Robots

Structure Documentation:

Subsystem

• Default Commands
  • Continuously executing until Interrupt

setDefaultCommand(new ExampleGroup());

• Relation To Robot
  • Subsystems can be compared to mechanisms that use the same overall resources
  • Realize that two actions that require the same subsystem cannot occur at the same time

• Dependencies
  • These prevent two different commands from utilizing the same resources on the robot
  • Dependencies are created by

requires(Robot.exampleSubsystem);

Commands

• Initialization
  • Initialization occurs when a command is run for the first time
  • This means that if a command is stopped and then run again the init() method will run twice

• Execution
  • The execute method inside of a command is must be concise and must not bog down the system or the entire robot may stop
  • This means that large loops and wait methods should not be inside of an execute command

• Interrupts
  • Called to stop a command from running
  • Specifically when robot is disabled or a dependency overlaps

• Connection With Buttons
  • Commands can be easily mapped to buttons through the OI class

• Manually Starting Commands
  • In order to manually start commands, create a new command object and run the start() method on the new command object
  • This may be very important when programming the autonomous robot

ExampleCommand cmd = new ExampleCommand()

cmd.start();

Input Class

• Input Devices
  • Input devices are mapped through joystick and button objects

Joystick js0 = new Joystick(0);

Button btn00 = new JoystickButton(js0, 0);

• Button Actions
  • Commands can be mapped to buttons or triggers in the OI class

btn00.whileHeld(new Command());

Robot Map

• Ports
  • This class centralizes port numbers and connection numbers for robot-wide use

public static int defaultMotor = 2;

Command Groups

• About
  • Command Groups are used for command sequencing and parallelization
  • Basically running things in a specific order or at the same time
  • Think about automated actions
  • Commands will add in order of methods to add them

• Parallel
  • Runs one command in the command group after the other without the need for an end command.

addParallel(new Command1());

• Ending Parallel
  • When an end() method is run in a parallel command group, the ended command is removed from the group until the next instance of the command is run.

• Sequential
  • Runs one command in the command group after the other with the need for an end() command before moving to the next command.

addSequential(new Command1());