inertial

Initializing the inertial Class

An Inertial Sensor is created by using the following constructor:

The inertial constructor creates an inertial object using the EXP Brain’s internal Inertial Sensor.

Parameter	Description
dir	The directionType which corresponds to a positive heading value. The default is right.

// Create a new object "Inertial" with the
// inertial class.
inertial Inertial = inertial();

The inertial(port, dir) constructor creates an inertial object using the EXP Brain’s internal Inertial Sensor.

Parameter	Description
port	A valid Smart Port that the Inertial Sensor is connected to.
dir	The directionType which corresponds to a positive heading value. The default is right.

// Construct a Inertial Sensor "Inertial" with the
// inertial class.
inertial Inertial = inertial(PORT1);

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

Class Methods

calibrate()

This method is called in the following ways:

The calibrate() method calibrates the Inertial Sensor. Calibration should be done when the Inertial Sensor is not moving.

Returns: None.

// Start calibration.
Inertial.calibrate();

The calibrate(value) method calibrates the Inertial Sensor. Calibration should be done when the Inertial Sensor is not moving.

Parameters	Description
value	Sets the amount of calibration time. The default is 0.

Returns: None.

// Start calibration with the calibration time set to 3 seconds.
Inertial.calibrate(3);

isCalibrating()

The isCalibrating() method checks if the Inertial Sensor is currently calibrating.

Returns: true if the Inertial Sensor is calibrating. false if it is not.

// Start calibration.
Inertial.calibrate();
// Print that the Inertial Sensor is calibrating while
// waiting for it to finish calibrating.
while(Inertial.isCalibrating()){
    Brain.Screen.clear();
    Brain.Screen.print("Inertial Calibrating");
    wait(50, msec);
}

resetHeading()

The resetHeading() method resets the heading of the Inertial Sensor to 0.

Returns: None.

setHeading()

The setHeading(value, units) method sets the heading of the Inertial Sensor to a specified value.

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

Returns: None.

// Set the Inertial Sensor's heading to 180 degrees.
Inertial.setHeading(180);

heading()

The heading(units) method returns the current heading of the Inertial Sensor.

Parameters	Description
units	A valid RotationUnit. The default is degrees.

Returns: A double representing the current heading of the Inertial Sensor in the specified units.

// Get the current heading for the Inertial Sensor.
double value = Inertial.heading();

resetRotation()

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

Returns: None.

setRotation()

The setRotation(value, units) method sets the rotation of the Inertial Sensor to a specified value.

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

Returns: None.

// Set the Inertial Sensor's rotation to 180 degrees.
Inertial.setRotation(180);

rotation()

The rotation(units) method returns the current rotation of the Inertial Sensor.

Parameters	Description
units	A valid RotationUnit. The default is degrees.

Returns: A double representing the current rotation of the Inertial Sensor in the specified units.

// Get the current rotation for the Inertial Sensor.
double value = Inertial.rotation();

angle()

The angle(units) method returns the current angle of the Inertial Sensor.

Parameters	Description
units	A valid RotationUnit. The default is degrees.

Returns: A double representing the current angle of the Inertial Sensor in the specified units.

// Get the current angle for the Inertial Sensor.
double value = Inertial.angle();

roll()

The roll(units) method returns the roll angle of the Inertial Sensor.

Parameters	Description
units	A valid RotationUnit. The default is degrees.

Returns: A double representing the roll value of the Inertial Sensor.

pitch()

The pitch(units) method returns the roll angle of the Inertial Sensor.

Parameters	Description
units	A valid RotationUnit. The default is degrees.

Returns: A double representing the pitch value of the Inertial Sensor.

yaw()

The yaw(units) method returns the yaw angle of the Inertial Sensor.

Parameters	Description
units	A valid RotationUnit. The default is degrees.

Returns: A double representing the yaw value of the Inertial Sensor.

orientation()

The orientation(axis, units) method returns the orientation for one axis of the Inertial Sensor.

Parameters	Description
axis	A valid AxisType.
units	A valid RotationUnit.

Returns: A double representing the value for the axis orientation in the units specified.

// Get the orientation value for the X axis of the
// Inertial Sensor.
double orient = Inertial.orientation(xaxis);

gyroRate()

The gyroRate(axis, units) method returns the gyro rate for one axis of the Inertial Sensor.

Parameters	Description
axis	A valid AxisType.
units	A valid VelocityUnit.

Returns: A double representing the value for the gyro rate of the axis in the units specified.

// Get the gyro rate for the Z axis of the Inertial Sensor.
double zrate = Inertial.gyroRate(zaxis);

acceleration()

The acceleration(axis) method returns the acceleration of a specific axis of the Inertial Sensor.

Parameters	Description
axis	A valid AxisType.

Returns: A double representing the value for the acceleration of the axis in units of gravity.

// Get the acceleration for the Z axis of the
// Inertial Sensor.
double accel = Inertial.acceleration(zaxis);

// Print the value of the current acceleration of the z-axis
// of the Inertial Sensor to the Brain's screen.
Brain.Screen.print(accel);

changed()

The changed(callback) method registers a callback function for when the Inertial Sensor heading changes.

Parameters	Description
callback	The callback function to be called when the Inertial Sensor heading changes.

Returns: An instance of the Event class.

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

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

  // Turn the robot right.
  Drivetrain.turn(right);

  // Run inertialChanged when the value of the
  // Inertial Sensor changes.
  Inertial.changed(inertialChanged);
}

collision()

The collision(axis, x, y, z) method registers a callback function for when the Inertial Sensor detects a collision.

Parameters	Description
axis	A valid AxisType.
x	A double for the acceleration values for the x axis.
y	A double for the acceleration values for the y axis.
z	A double for the acceleration values for the z axis.

Returns: An instance of the Event class.

timestamp()

The timestamp() method requests the timestamp of the last received status packet from the Inertial Sensor.

Returns: Timestamp of the last status packet as an unsigned 32-bit integer in milliseconds.

installed()

The installed() method returns if the Inertial Sensor is installed.

Returns: true if the Inertial Sensor is installed. false if it is not.