Optical Sensor#

Introduction#

The optical class is used to access data from the V5 Optical Sensor. It uses reflected light to detect objects, identify colors, and measure brightness and hue.

Class Constructor#

optical Optical = optical(index);

Class Destructor#

Destroys the optical object and releases associated resources.

virtual ~optical();

Parameters#

Parameter

Type

Description

index

int32_t

The Smart Port that the Optical Sensor is connected to, written as PORTx, where x is the port number (for example, PORT1).

Examples#

// Create an optical instance in Port 1
optical Optical1 = optical(PORT1);

Member Functions#

The optical class includes the following member functions:

  • setLight — Turns the Optical Sensor’s LED on or off.

  • setLightPower — Sets the Optical Sensor’s LED to a specific brightness.

  • isNearObject — Returns whether or not an object is close to the sensor.

  • color — Return the detected color as a predefined color object.

  • brightness — Returns the detected brightness of an object.

  • hue — Returns the detected hue value.

  • objectDetected — Registers a function to be called when the Optical Sensor detects an object.

  • objectLost — Registers a function to be called when the Optical Sensor loses an object.

Before calling any optical member functions, an optical instance must be created, as shown below:

// Create an optical object in Port 1
optical Optical1 = optical(PORT1);

setLight#

Sets Optical Sensor’s LED to on or off.

Available Functions 
void  setLight(ledState state);
Parameters

Parameter

Type

Description

state

ledState

A valid ledState:

  • ledState::off
  • ledState::on
Return Values

This function does not return a value.

Examples 
// Turn on LED with previous intensity.
Optical.setLight(ledState::on);

setLightPower#

Sets the light power of the Optical Sensor’s LED.

Available Functions 
void setLightPower( 
      int32_t      intensity, 
      percentUnits units = percent );

Parameter

Type

Description

intensity

int32_t

The power level to set the light from 0 – 100.

units

percentUnits

The unit that represents the light intensity:

  • percent / pct — percent

Return Values

This function does not return a value.

Examples 
// Set the light power to 50 percent.
Optical.setLightPower(50, percent);

isNearObject#

Returns if the Optical Sensor detects a nearby object.

Available Functions 
bool  isNearObject();
Parameters

This function does not accept any parameters.

Return Values

This function returns a Boolean indicating if a nearby object is detected:

  • true — An object is detected nearby.

  • false — An object is not detected.

Examples 
// If an object is detected yb the Optical Sensor, print
// "near object".
if (Optical.isNearObject()){
  Brain.Screen.print("near object");
}

color#

Returns the color detected by the Optical Sensor.

Available Functions 
vex::color  color();
Parameters

This function does not accept any parameters.

Return Values

The color detected by the Optical Sensor as an instance of the color class.

Examples 
// Set a variable, detectColor, to the color detected by the
// Optical Sensor.
color detectColor = Optical.color();

// Print the color detected by the Optical Sensor
// to the Brain's screen.
brain.screen.print(detectColor);

brightness#

Returns the brightness detected by the Optical Sensor.

Available Functions 
double  brightness(bool bRaw = false);
Parameters

Parameter

Type

Description

bRaw

bool

A Boolean value to read raw brightness data instead of percentage. The default is false.
Return Values

A double representing the brightness detected by the Optical Sensor as a float in the range 0 - 100%, or a double representing the raw data detected by the sensor.

Examples 
// Set a variable, brightness, to the value of the brightness
// detected by the Optical Sensor.    
double brightness = Optical.brightness();

// Print the brightness detected by the Optical Sensor to the
// Brain's screen.
brain.screen.print(brightness);

hue#

Returns the value of the hue detected by the Optical Sensor.

Available Functions 
double hue();
Parameters

This function does not accept any parameters.

Return Values

A double representing the value of the hue detected by the Optical Sensor as a float in the range 0 — 359.99.

Examples 
// Set a variable, hue, to the value of the hue detected
// by the Optical Sensor.
double hue = Optical.hue();

objectDetected#

Registers a callback function for when an object is detected.

Available Functions 
void objectDetected(void (* callback)(void));
Parameters

Parameter

Type

Description

callback

void (*)(void)

The callback function to be called when an object is detected.
Return Values

This function does not return a value.

Examples 
// Define the lost function with a void return type,
// showing it doesn't return a value.
void detected() {
  // The Brain will print that the Optical Sensor detected an
  // object to the Brain's screen.
  Brain.Screen.print("object detected");
}

// Run lost when the Optical Sensor detects an object.
Optical.objectDetected(detected);

objectLost#

Registers a callback function for when an object is lost.

Available Functions 
void objectLost(void (* callback)(void));
Parameters

Parameter

Type

Description

callback

void (*)(void)

The callback function to be called when an object is lost.
Return Values

This function does not return a value.

Examples 
// Define the lost function with a void return type,
// showing it doesn't return a value.
void lost() {
  // The Brain will print that the Optical Sensor lost an
  // object to the Brain's screen.
  Brain.Screen.print("object lost");
}

// Run lost when the Optical Sensor loses an object.
Optical.objectLost(lost);
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