Using Built-In Attachments

Volt has several built-in Attachments that can be used to quickly add functionality to your Robots.

These Attachments include:

DcMotorAttachment: Controls a single DcMotor
ServoAttachment: Controls a single Servo
CRServoAttachment: Controls a single CRServo
CRServoWithPotentiometerAttachment: Controls a CRServo with an AnalogInput measuring its angular displacement

Using Built-In Attachments

There are two main ways to use a built-in attachment:

As-is: Relies on existing Actions
Extended: Extends the existing implementation

As-is

To use a built-in Attachment as-is, simply create a new instance of the Attachment in your Robot class:

Kotlin
Java

class MyRobot(hardwareMap: HardwareMap) : Robot(hardwareMap) {
    private val clawServo by servo("clawServo")

    val claw = attachment { ServoAttachment("Claw", clawServo) }
}

public class MyRobot extends Robot {
    private final Servo clawServo;
    public final ServoAttachment claw;

    public MyRobot(HardwareMap hardwareMap) {
        super(hardwareMap);
        clawServo = hardwareMap.get(Servo.class, "clawServo");
        claw = attachment(() -> {
            return new ServoAttachment(
                    "Claw",
                    clawServo
            );
        });
    }
}

Extended

To extend a built-in Attachment, create a new class that inherits the Attachment:

Kotlin
Java

class Claw(servo: Servo) : ServoAttachment("Claw", servo) {
    // Custom functionality can be added here
}

public class Claw extends ServoAttachment {
    public Claw(Servo servo) {
        super("Claw", servo);
    }

    // Custom functionality can be added here
}

Simple Built-in Attachments Reference

The simplest built-in attachments control a single hardware actuator. These types of Attachments are very common.

`DcMotorAttachment`

Constructor Parameters

name: String: The name of the DcMotorAttachment
motor: DcMotor: The motor to control
maxPosition: Int: The maximum position of the motor in encoder ticks
minPosition: Int: The minimum position of the motor in encoder ticks
direction: DcMotorSimple.Direction: The direction the motor should spin

Properties

currentGoal: Int: The position of the current goal in encoder ticks

Actions

reset(): Resets the motor’s encoder
goTo(power: Double, position: Int): Moves the motor to the specified position in encoder ticks at the specified power

Telemetry

Logs the current goal, current position, and whether the motor is running. Example output:

Goal 0
Position 0
Busy false

`ServoAttachment`

Constructor Parameters

name: String: The name of the ServoAttachment
servo: Servo: The servo to control
direction: Servo.Direction: The direction the servo should spin

Properties

position: ServoPosition: The position of the servo

Actions

goTo(target: ServoPosition): Moves the servo to the specified target servo position

Telemetry

Logs the current position of the servo. Example output:

Position 0.0

`CRServoAttachment`

Constructor Parameters

name: String: The name of the CRServoAttachment
crServo: CRServo: The cr servo to control
direction: DcMotorSimple.Direction: The direction the cr servo should spin

Properties

None

Actions

moveFor(power: Power, seconds: Seconds): Moves the cr servo for the specified number of seconds at the specified power
start(power: Power): Starts the cr servo at the specified power

Telemetry

Logs the current power being applied to the cr servo. Example output:

Power 0.0

Using Built-In Attachments