OpModes

OpModes in the context of the provided project are classes that control the robot's behavior. They are part of the robot control system and are used to define the actions the robot should perform during different phases of operation. Here's a detailed description of how OpModes work:

Initialization (init() method)

The init() method is called once when the user presses the INIT button on the Driver Station. This method is used to set up any necessary configurations or initial states before the robot starts running.

Running (run() method)

Once the user presses the Play button, the run() method is executed. The run() method is run once, and any continuous actions need to be placed inside a while loop to keep running as long as the OpMode is active.

Stopping (onStop() method)

The onStop() method is called when the user presses the Stop button on the Driver Station. It is also called if a timer on the Driver Station reaches zero. This method is used to clean up or stop any ongoing actions safely.

Scripts

Scripts are components that can be added to an OpMode. They are not controlled by the Driver Station but are added in the init() function of an OpMode. Multiple scripts can be added to an OpMode, and they are reusable between different OpModes.

Hardware Management

The HardwareManager class is used to control the hardware objects available to the robot. These hardware objects should be configured in the Driver Station.

OpMode Annotations

OpMode annotations are used to register and categorize OpModes in the robot control system. These annotations provide metadata that helps the system identify and organize the OpModes. Here are the key annotations used:

@TeleOp

The @TeleOp annotation is used to mark an OpMode as a teleoperated mode. This means the OpMode is intended to be run during the teleoperated period of a match, where the robot is controlled by drivers using gamepads.

Example:

@TeleOp(name = "Simple Mecanum OpMode", group = BaseOpMode.DRIVETRAIN_GROUP_NAME)
class SimpleMecanumOpMode: BaseOpMode() {
    // OpMode implementation
}

@Autonomous

The @Autonomous annotation is used to mark an OpMode as an autonomous mode. This means the OpMode is intended to be run during the autonomous period of a match, where the robot operates based on pre-programmed instructions without driver input.

Example:

@Autonomous(name = "Simple Autonomous OpMode", group = BaseOpMode.DRIVETRAIN_GROUP_NAME)
class SimpleAutonomousOpMode: BaseOpMode() {
    // OpMode implementation
}

Parameters

Both @TeleOp and @Autonomous annotations accept the following parameters:

• name: A string representing the name of the OpMode. This name will be displayed on the Driver Station.
• group: A string representing the group name of the OpMode. This is used to categorize OpModes into different groups for easier navigation on the Driver Station.

There are certain constants defined in the BaseOpMode class that can be used for group names:

• BaseOpMode.DRIVETRAIN_GROUP_NAME: Group name for drivetrain-related OpModes.
• BaseOpMode.DEBUG_GROUP_NAME: Group name for debug-related OpModes.
• BaseOpMode.FULL_GROUP_NAME: Group name for OpModes that represent a fully-featured robot.
• BaseOpMode.AUTONOMOUS_GROUP_NAME: Group name for autonomous-related OpModes.

Example

Here is an example of a simple OpMode:

@TeleOp(name = "Simple Mecanum OpMode", group = BaseOpMode.DRIVETRAIN_GROUP_NAME)
class SimpleMecanumOpMode: BaseOpMode() {
    override fun construct() {
        addScript(MecanumDriveScript())
    }

    override fun run() {
        // Main loop code here
    }

    override fun onStop() {
        // Cleanup code here
    }
}

In this example:

• The construct() method adds a MecanumDriveScript to the OpMode.
• The run() method would contain the main loop code.
• The onStop() method would contain any cleanup code needed when the OpMode stops.

Uplooading OpModes

To upload OpModes to the robot controller, you need to connect the robot controller to your computer via USB and press the play button in Android Studio. This will compile the code and upload it to the robot controller. Once the code is uploaded, you can select the OpMode on the Driver Station and run it on the robot.

NOTE

You will need either a USB-C to USB-C or USB-A to USB-C cable to connect the robot controller to your computer. If you connect the USB-A end to the robot controller, it will not show up in Android Studio.

How OpModes Work Internally

The multithreaded model of OpModes in the provided project allows for concurrent execution of the main robot control logic and additional scripts. When an OpMode starts, a hidden method called runOpMode() method initializes the hardware and calls the construct() method to set up any necessary configurations. After waiting for the start signal, it starts the main thread, which runs the run() method containing the primary control loop. Concurrently, any scripts added to the OpMode are also started in their own threads. This setup ensures that the main control logic and scripts can run simultaneously, allowing for more complex and responsive robot behavior.

During the execution of the OpMode, the system continuously checks if the OpMode is active and manages the lifecycle of the threads. If a script's thread terminates unexpectedly, it is removed from the list of active scripts. When the OpMode stops, either due to user intervention or a timer, all threads are interrupted and joined to ensure they terminate safely. The onStop() method is then called to perform any necessary cleanup. This multithreaded approach provides a robust framework for managing multiple concurrent tasks within an OpMode, enhancing the robot's ability to perform complex operations efficiently.