Eye

Introduction

The VR Eye Sensor can detect objects and identify their color, brightness, and hue. It also allows you to adjust detection range and lighting settings for more accurate readings.

Below is a list of all available methods:

Getters – Read object presence, color, brightness, and hue.

• near_object – Returns whether the Eye Sensor detects an object within range.

• detect – Returns whether the Eye Sensor detects a specific color.

• brightness – Returns the amount of light reflected from the object as a percent.

Callback – Run code when an object is detected or lost.

• object_detected – Registers a function to be called whenever the Eye Sensor detects an object.

• object_lost – Registers a function to be called whenever the Eye Sensor loses an object.

Getters

near_object

near_object returns a Boolean that reports whether or not the Eye Sensor detects an object within range.

• True – The sensor is near an object.

• False – The sensor is not near an object.

Usage:
eye.near_object()

Parameters	Description
	This method has no parameters.

def main():
    # Stop driving when Eye Sensor is 
    # near an object
    drivetrain.drive(FORWARD)
    while True:
        if front_eye.near_object():
            drivetrain.stop()
        wait(5, MSEC)

# VR threads — Do not delete
vr_thread(main)

detect

detect returns a Boolean that reports whether the Eye Sensor detects a specified color, based on the detected hue value.

• True — The Eye Sensor detects the selected color.

• False — The Eye Sensor does not detect the selected color.

Usage:
eye.detect(color)

Parameters	Description
color	The color for the Eye Sensor to check for: BLUE GREEN NONE RED

def main():
    # Stop the robot if the Eye Sensor 
    # detects red
    drivetrain.turn(RIGHT)
    while True:
        if front_eye.detect(RED):
            drivetrain.stop()
        wait(5, MSEC)

# VR threads — Do not delete
vr_thread(main)

brightness

brightness returns the amount of light reflected from the object as a decimal (float) representing a percent.

A higher percentage means more light is reflected back to the Eye Sensor. A lower percentage means less light is reflected back.

Usage:
eye.brightness(units)

Parameters	Description
units	The unit that represents the brightness: PERCENT

Callback

object_detected

object_detected registers a function to be called whenever the Eye Sensor detects a new object.

Usage:
eye.object_detected(callback)

Parameters	Description
callback	A previously defined function that executes when the Eye Sensor detects a new object.

def detected():
    # Display a message
    drivetrain.stop()
    brain.print("object detected")
    wait(0.5,SECONDS)
    brain.clear()

def main():
    # Drive until an object is detected
    drivetrain.drive(FORWARD)
    front_eye.object_detected(detected)

# VR threads — Do not delete
vr_thread(main)

object_lost

object_lost registers a function to be called whenever the Eye Sensor loses a detected object.

Usage:
eye.object_lost(callback)

Parameters	Description
callback	A previously defined function that executes when the Eye Sensor loses a detected object.

def lost():
    # Display a message
    drivetrain.stop()
    brain.print("object lost")
    wait(0.5,SECONDS)
    brain.clear()

def main():
    # Back away from an object
    drivetrain.drive(REVERSE)
    front_eye.object_lost(lost)

# VR threads — Do not delete
vr_thread(main)