TeleOp

Creating a TeleOp in NextFTC is just as easy as autonomous! This page will walk you through creating a TeleOp. This page assumes you have already read the Autonomous guide.

This TeleOp program will teach you how to bind commands to gamepad buttons and control your drivetrain using NextFTC.

Step 1: Create your class

Just like for autonomous, your OpMode will extend either NextFTCOpMode or PedroOpMode. However unlike autonomous, this page will cover both.

NOTE

The main thing PedroPathing is used for in TeleOp is centripetal force correction while driving, which prevents your robot from "bulging" out while turning. It is completely a matter of preference whether or not to use it. If you are not using PedroPathing in your TeleOp, you do not need to extend PedroOpMode, even if you have PedroPathing in your project.

With that in mind, here is the basic structure for a TeleOp:

@TeleOp(name = "NextFTC TeleOp Program Kotlin")
class TeleOpProgram: NextFTCOpMode() {

}

Don't forget to replace NextFTCOpMode with PedroOpMode if you want to use PedroPathing.

Just like for autonomous, we need to add the required subsystems into the constructor of our OpMode:

class TeleOpProgram: NextFTCOpMode(Claw, Lift) {

That's all! Now we will allow the joysticks to control our robot's driving.

Step 2: Create your drive command

NextFTC has built in commands for common drivetrains.

IMPORTANT

Currently, NextFTC only has support for mecanum, x-drive, and differential (tank) drivetrains. If you write a command for another, please share it with us!

Go to the drivetrain commands page to get the code for your drivetrain. In this guide I will be using the MecanumDriverControlled command. If you are using a different drivetrain command, follow the instructions there to get it set up and then come back to this guide.

After adding the MecanumDriverControlled command, here is our code:

@TeleOp(name = "NextFTC TeleOp Program Kotlin")
class TeleOpProgram: NextFTCOpMode(Claw, Lift) {

    // Change the motor names to suit your robot.
    val frontLeftName = "front_left"
    val frontRightName = "front_right"
    val backLeftName = "back_left"
    val backRightName = "back_right"

    lateinit var frontLeftMotor: MotorEx
    lateinit var frontRightMotor: MotorEx
    lateinit var backLeftMotor: MotorEx
    lateinit var backRightMotor: MotorEx

    lateinit var motors: Array<MotorEx>

    lateinit var driverControlled: Command

    override fun onInit() {
        frontLeftMotor = MotorEx(frontLeftName)
        backLeftMotor = MotorEx(backLeftName)
        backRightMotor = MotorEx(backRightName)
        frontRightMotor = MotorEx(frontRightName)

        // Change the motor directions to suit your robot.
        frontLeftMotor.direction = DcMotorSimple.Direction.REVERSE
        backLeftMotor.direction = DcMotorSimple.Direction.REVERSE
        frontRightMotor.direction = DcMotorSimple.Direction.FORWARD
        backRightMotor.direction = DcMotorSimple.Direction.FORWARD

        motors = arrayOf(frontLeftMotor, frontRightMotor, backLeftMotor, backRightMotor)
    }

    override fun onStartButtonPressed() {
        driverControlled = MecanumDriverControlled(motors, gamepadManager.gamepad1)
        driverControlled()
    }
}

Step 3: Create your gamepad bindings

In the last guide you learned how to schedule a command when the OpMode starts. Now you will learn how to schedule a command whenever the driver presses a button.

In this guide, we will have the following buttons, all on gamepad 2:

• Pressing d-pad up moves the lift up.
• Releasing d-pad up opens the claw.
• Pressing the right trigger closes the claw and then moves the lift up.
• Pressing the left bumper opens the claw and at the same time moves the lift down.

NOTE

It is unlikely that these commands will be useful for any real robot, but it will give you an idea of how you can achieve practically any gamepad bindings possible with NextFTC.

TIP

It is best to have the most commonly used functions activated by bumpers and triggers. This is because to press any other button, your thumb must move, while no finger has to move to press the bumpers and triggers.

To bind commands to buttons, we will use gamepadManager. You can access gamepadManager in any NextFTCOpMode or PedroOpMode. Instead of using the Qualcomm gamepads, you interact with an instance of GamepadEx, which is a wrapper over gamepads.

You can access the gamepads with gamepadManager.gamepad1 and gamepadManager.gamepad2.

Accessing buttons is simple; for example, gamepadManager.gamepad1.x or gamepadManager.gamepad2.dpadUp.

There are four types of bindings you can give a button:

• pressedCommand is called on the rising edge. That is, the first loop when the button is pressed.
• heldCommand is called every loop where the button is pressed.
• releasedCommand is called on the falling edge. That is, the first loop when the button is not pressed.
• stateChangedCommand is called on both the rising edge and the falling edge.

To set a command, you set one of those four bindings to a lambda that returns the command. For example:

gamepadManager.gamepad1.x.pressedCommand = { Claw.open }

We will bind our commands in onStartButtonPressed(). If we wanted them accessible in init, we would do it in onInit().

CAUTION

Although it is possible to bind the commands in init, keep in mind that your robot is not allowed to move during the transition from autonomous to TeleOp. There is almost never a time you would want to use the gamepads during init.

First, we will make d-pad up move the lift up when pressed:

gamepadManager.gamepad2.dpadUp.pressedCommand = { Lift.toHigh }

Next, we will make it so releasing d-pad up opens the claw:

gamepadManager.gamepad2.dpadUp.releasedCommand = { Claw.open }

NOTE

If d-pad up is released before the lift has fully finished moving up, then the claw will open while the lift is moving up.

Now, we must make the right trigger close the claw and then move the lift up. To do this, we can use a SequentialGroup!

gamepadManager.gamepad2.rightTrigger.pressedCommand = {
    SequentialGroup(
        Claw.close,
        Lift.toHigh
    )
 }

Lastly, we must make the left bumper open the claw and at the same time move the lift down. We can use a ParallelGroup for this!

gamepadManager.gamepad2.leftBumper.pressedCommand = {
    ParallelGroup(
        Claw.open,
        Lift.toLow
    )
}

Final Result

That's all! You now have created a TeleOp program with driving and operating the lift and claw. You also now know how to create any TeleOp you wish, even if it has complicated sequences.

For reference, here is the final result:

@TeleOp(name = "NextFTC TeleOp Program Kotlin")
class TeleOpProgram: NextFTCOpMode(Claw, Lift) {

    val frontLeftName = "front_left"
    val frontRightName = "front_right"
    val backLeftName = "back_left"
    val backRightName = "back_right"

    lateinit var frontLeftMotor: MotorEx
    lateinit var frontRightMotor: MotorEx
    lateinit var backLeftMotor: MotorEx
    lateinit var backRightMotor: MotorEx

    lateinit var motors: Array<MotorEx>

    lateinit var driverControlled: Command

    override fun onInit() {
        frontLeftMotor = MotorEx(frontLeftName)
        backLeftMotor = MotorEx(backLeftName)
        backRightMotor = MotorEx(backRightName)
        frontRightMotor = MotorEx(frontRightName)

        // Change your motor directions to suit your robot.
        frontLeftMotor.direction = DcMotorSimple.Direction.REVERSE
        backLeftMotor.direction = DcMotorSimple.Direction.REVERSE
        frontRightMotor.direction = DcMotorSimple.Direction.FORWARD
        backRightMotor.direction = DcMotorSimple.Direction.FORWARD

        motors = arrayOf(frontLeftMotor, frontRightMotor, backLeftMotor, backRightMotor)
    }

    override fun onStartButtonPressed() {
        driverControlled = MecanumDriverControlled(motors, gamepadManager.gamepad1)
        driverControlled()

        gamepadManager.gamepad2.dpadUp.pressedCommand = { Lift.toHigh }

        gamepadManager.gamepad2.dpadUp.releasedCommand = { Claw.open }

        gamepadManager.gamepad2.rightTrigger.pressedCommand = {
            SequentialGroup(
                Claw.close,
                Lift.toHigh
            )
        }

        gamepadManager.gamepad2.leftBumper.pressedCommand = {
            ParallelGroup(
                Claw.open,
                Lift.toLow
            )
        }
    }
}