encoder

Initializing the encoder Class

An Encoder Sensor is created by using the following constructor:

The encoder constructor creates an encoder object in the specified Three Wire Port:

Parameter	Description
port	The 3-Wire Port “pair” that the Encoder Sensor is connected to, whether it’s a port on the Brain, or a 3-Wire Expander. Note: An Encoder Sensor uses two adjacent 3-Wire ports. These pairs are a/b, c/d, e/f, and g/h. When entering the pair as an argument, use the first letter of the pair, ie: Brain.ThreeWirePort.A refers to the a/b pair.

A Brain or 3-Wire Expander must be created first before they can be used to create an object with the Encoder Class constructor.

// Create the Brain.
brain Brain;
// Construct an Encoder Sensor "Encoder" with the
// encoder class.
encoder Encoder = encoder(Brain.ThreeWirePort.A);

This Encoder object will be used in all subsequent examples throughout this API documentation when referring to encoder class methods.

Class Methods

resetRotation()

The resetRotation() method resets the rotation of the Encoder Sensor to 0.

Returns: None.

setRotation()

The setRotation(value, units) method sets the rotation of the Encoder Sensor.

Parameters	Description
value	The rotation value to set.
units	A valid RotationUnit.

Returns: None.

// Set the Encoder Sensor's value of rotation to 180 degrees.
Encoder.setRotation(180);

setPosition()

The setPosition(value, units) method sets the position of the Encoder Sensor.

Parameters	Description
value	The rotation value to set.
units	A valid RotationUnit.

Returns: None.

// Set the Encoder Sensor's value of position to 180 degrees.
Encoder.setPosition(180);

rotation()

The rotation(units) method returns the rotation value of the Encoder Sensor.

Parameters	Description
units	A valid RotationUnit.

Returns: A double that represents the current rotation of the Encoder.

// Get the current encoder rotation.
double value = Encoder.rotation();

position()

The position(units) method returns the current position of the Encoder Sensor.

Parameters	Description
units	A valid RotationUnit.

Returns: The value of the current position of the Encoder Sensor in the specified units.

// Get the current Encoder Sensor's position.
double value = Encoder.position();

velocity()

The velocity(units) method returns the current velocity of the Encoder Sensor.

Parameters	Description
units	A valid VelocityUnit.

Returns: A double representing the value of the current velocity of the Encoder Sensor in the specified units.

// Get the current Encoder Sensor's velocity in rpm.
double value = Encoder.velocity();

changed()

The changed(callback) method registers a function to be called when the value of the Encoder Sensor changes.

Parameters	Description
callback	A function that will be called when the Encoder Sensor’s axis value changes.

Returns: An instance of the Event class.

// Define the encoderChanged function with a void return
// type, showing it doesn't return a value.
void encoderChanged() {
  // The Brain will print that the Encoder Sensor changed on
  // the Brain's screen.
  Brain.Screen.print("encoder changed");
}

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Drive the robot forward.
  Drivetrain.drive(forward);

  // Run encoderChanged when the value of the
  // Encoder Sensor changes.
  Encoder.changed(encoderChanged);
}