Seamonsters-2605.github.io

Subsystem Controller Classes

A subsystem is a collection of motors/sensors on the robot that has a specific purpose. Each year our robot has a few subsystems. Last year we had 3:

• Drivetrain (for movement)
• Conveyor (for manipulating cubes)
• Wings (for lifting other robots)
• Bonus #4: LED light display on the wings

Each subsystem will live in its own .py file and have its own Controller class. Controller classes are responsible for managing all of the resources associated with the subsystem (motors, sensors, etc.), and have functions/generators for all of the basic actions of the subsystem. The Controller class does not know about driver controls like joysticks, or any other subsystems. A Controller class is not a robot.

Here’s what a controller class looks like.

class SubsystemController:

    def __init__(self):
        # this function is called when the controller object is created by the robot. initialize resources here
    
    def doSomething(self, arg1, arg2, arg3):
        # do something...

Here’s how you might use this controller class in your robot:

# import the things
import my_subsystem

class MyRobot(sea.GeneratorBot):

    def robotInit(self):
        self.subsystem = my_subsystem.SubsystemController()
    
    def teleop(self):
        self.subsystem.doSomething(1, 2, 3)

# etc.

Activity

Your task is to write a subsystem controller for the conveyor on our 2018 robot.

The conveyor subsystem has 4 motors:

• A left and right conveyor motor
• A left and right intake motor

Your controller should include these functions:

• Load the cube by running the conveyor and intake slowly
• Drop the cube (reverse of loading cube)
• Shoot the cube by running the conveyor quickly
• Stop all motors

It should also include these autonomous generators:

• Shoot the cube for 1 second and stop
• Drop the cube for 1 second and stop
• Pulse the intake (move back and forth forever)

All of these generators should have a stop condition so that the motors properly stop if the generators are interrupted early. You can use a try/finally block for this:

try:
    # do the thing
finally:
    # stop the thing

Finally, write a robot class in a separate file which attaches joystick controls to each of these actions.