Object Sensor

Introduction

The objectdetector class is used to measure reflectivity and detect objects by the Object Sensor.

Class Constructor

objectdetector( 
  triport::port &port, 
  bool           bReverse = false );

Class Destructor

Destroys the objectdetector object and releases associated resources.

virtual ~objectdetector();

Parameters

Parameter	Type	Description
port	triport::port &	The 3-Wire Port that the Object Sensor is connected to, written as Brain.ThreeWirePort.X or ExpanderName.X, where X is the port letter (for example, Brain.ThreeWirePort.A or Expander1.A).
bReverse	bool	An optional boolean to reverse the direction of the Object Sensor: false (default) — Do not reverse the direction true — Reverse the direction

Examples

// Create an objectdetector instance in Port A
objectdetector ObjectSensorA = objectdetector(Brain.ThreeWirePort.A, true);

Member Functions

The objectdetector class includes the following member functions:

• reflectivity — Returns the reflectivity detected by the Object Sensor.

• isObjectDetected — Returns whether the Object Sensor detects an object.

• setDetectionThreshold — Sets the detection range of the Object Sensor.

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

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

Before calling any objectdetector member functions, a objectdetector instance must be created, as shown below:

// Create an objectdetector instance in Port A
objectdetector ObjectSensorA = objectdetector(Brain.ThreeWirePort.A, true);

reflectivity

Returns the reflectivity measured by the Object Sensor.

Available Functions

int32_t reflectivity( 
  percentUnits units = percentUnits::pct );

Parameters

Parameters	Type	Description
units	percentUnits	The unit that represents the reflectivity: percent / pct — percent

Return Values

Returns an int32_t representing the reflectivity measured by the Object Detector as a percent in the range 0 - 100%.

Examples

// Display the detected reflectivity on the Brain's screen
int32_t value = ObjectSensorA.reflectivity();
Brain.Screen.print(value);

isObjectDetected

Returns whether an object is currently detected by the Object Detector.

Available Functions

bool isObjectDetected();

Parameters

This function does not take any parameters.

Return Values

Returns a Boolean indicating whether an object is detected:

• true — An object is detected.
• false — No object is detected.

setDetectionThreshold

Sets the detection threshold for the Object Detector to a specific value.

Available Functions

void setDetectionThreshold( 
  int32_t      threshold, 
  percentUnits units = percentUnits::pct );

Parameters

Parameters	Type	Description
threshold	int32_t	The reflectivity threshold for object detection, in the range 0 - 100.
units	percentUnits	The unit that represents the new threshold: percent / pct — percent

Return Values

This function does not return a value.

Examples

// Set the reflectivity threshold to 50%
ObjectSensorA.setDetectionThreshold(50);

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

void detected() {
  Brain.Screen.print("object detected");
}

// Run detected when the Object Detector detects an object
ObjectSensorA.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

void lost() {
  Brain.Screen.print("object lost");
}

// Run lost when the Object Detector loses an object
ObjectSensorA.objectLost(lost);