Command-Based Programming

As robot programs grow, even state machines can become difficult to manage.

Command-based programming provides a cleaner way to organize robot behavior.

The main idea is:

Subsystems represent what the robot has. Commands represent what the robot does.

Subsystems

Subsystems are the different parts of your robot.

Examples:

• Drivetrain
• Intake
• Shooter
• Arm
• Turret

A subsystem contains the hardware and logic needed to control that mechanism.

Commands

Commands represent actions.

Examples:

• Drive forward
• Shoot a game piece
• Move an arm
• Intake an object

Instead of manually controlling every step:

if (shooting) {
    shooter.run();
}

You create reusable actions:

new ShootCommand();

Command Scheduling

A scheduler manages which commands are currently running.

This allows multiple systems to work together:

Drive Command
        +
Shooter Command
        +
Intake Command

The robot can perform complex actions without one giant loop of conditions.

FTC Libraries

Several FTC libraries can help you implement command-based programming:

• FTCLib (Unfortunately the docs don't work anymore)
• Mercurial
• SolversLib (FTCLib's Successor)
• NextFTC
• Ivy by Pedro Pathing

These libraries provide tools for creating commands and organizing subsystems.

Command-based programming is not a replacement for understanding control flow. It is a structure built on top of ideas like loops, states, and events.