sonar

Initializing the sonar Class

A Range Finder is created by using the following constructor:

The sonar constructor creates a sonar object in the specified Three Wire Port.

Parameter	Description
port	The 3-Wire Port “pair” that the Range Finder is connected to, whether it’s a port on the Brain, or a 3-Wire Expander. Note: A Range Finder 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 sonar Class constructor.

// Create the Brain.
brain Brain;
// Construct a Range Finder "Sonar" with the
// sonar class.
sonar Sonar = sonar(Brain.ThreeWirePort.A);

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

Class Methods

distance()

The distance(units) method returns the current distance the Range Finder is detecting on abject at. The Range Finder will return a large positive number if no object is detected in range.

Parameters	Description
units	A valid DistanceUnit.

Returns: A double representing the distance measured by the Range Finder.

// Get the Range Finder distance in millimeters.
double value = Sonar.distance(mm);

// Print the current distance detected by the Range Finder to the
// Brain's screen.
Brain.Screen.print(value);

foundObject()

The foundObject() method checks if an object is detected by the Range Finder in the range 0 - 1000 millimeters. The Range Finder will return true if an object is detected closer than 1000mm.

Returns: true if an object is detected by the Range Finder. false if one is not.

// Check if an object is 1000mm or closer to the Range Finder.
if (Sonar.foundObject()){
    // Print to screen on the brain that an object was found.
    Brain.Screen.print("object found");
}

setMaximum()

The setMaximum(distance, units) method sets the maximum distance the foundObject() method will return true for.

Parameters	Description
distance	A double representing the maximum distance the Range Finder will find objects at.
units	A valid DistanceUnit.

Returns: None.

changed()

The changed(callback) method runs a callback function when the Range Finder’s value changes.

Parameters	Description
callback	A callback function to run when the value of the Range Finder changes.

Returns: None.

// Define the sonarChanged function with a void return type,
// showing it doesn't return a value.
void sonarChanged() {
  // The Brain will print that the value detected by the
  // Range Finder changed on the Brain's screen.
  Brain.Screen.print("Range Finder value changed");
}

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

  // Run sonarChanged when the value of the
  // Range Finder changes.
  Sonar.changed(sonarChanged);
}