Feedback Servos

NextFeedbackServo and NextFeedbackCRServo pair a NextServo or NextCRServo with an analog feedback input, for servos with a feedback wire (e.g. Axon). They inherit everything from their base class and add angle for reading the servo’s actual physical angle.

Creating a feedback servo

Both classes pair the constructors you already know from NextServo and NextCRServo with an already-constructed AnalogFeedback instance for reading the angle. NextAnalogInput is the built-in implementation of AnalogFeedback, and is what you’ll use in most cases. All of these below are interchangeable with NextFeedbackCRServo.

Kotlin

// By configuration name
val armServo = NextFeedbackServo("armServo", NextAnalogInput("armEncoder"))

// By Lynx Module and port
val armServo = NextFeedbackServo(RobotController.expansionHub, 0, NextAnalogInput(RobotController.expansionHub, 0))

Java

// By configuration name
NextFeedbackServo armServo = new NextFeedbackServo("armServo", new NextAnalogInput("armEncoder"));

// By Lynx Module and port
NextFeedbackServo armServo = new NextFeedbackServo(RobotController.getExpansionHub(), 0, new NextAnalogInput(RobotController.getExpansionHub(), 0));

feedback accepts any AnalogFeedback implementation, so you can also write your own if NextAnalogInput doesn’t fit what you want. AnalogFeedback just needs a maxVoltage and a Supplier<Double> that returns the raw voltage from wherever you’re reading it

Kotlin

val myAnalogInput = hardwareMap.get(AnalogInput::class.java, "armEncoder")

val customFeedback = AnalogFeedback(maxVoltage = 3.3.volts) { myAnalogInput.voltage }

val armServo = NextFeedbackServo("armServo", customFeedback)

Java

AnalogInput myAnalogInput = hardwareMap.get(AnalogInput.class, "armEncoder");

AnalogFeedback customFeedback = new AnalogFeedback(3.3.volts, () -> myAnalogInput.getVoltage());

NextFeedbackServo armServo = new NextFeedbackServo("armServo", customFeedback);

Usage

angle

The servo’s actual physical angle, read from the analog feedback input and returned as a typed Angle.

Kotlin

val currentAngle = armServo.angle

Java

Angle currentAngle = armServo.getAngle();