Gyro Class Reference

#include <Gyro.h>

Inheritance diagram for Gyro:

List of all members.

Public Member Functions
	Gyro (UINT8 moduleNumber, UINT32 channel)
	Gyro (UINT32 channel)
	Gyro (AnalogChannel *channel)
	Gyro (AnalogChannel &channel)
virtual	~Gyro ()
virtual float	GetAngle ()
void	SetSensitivity (float voltsPerDegreePerSecond)
virtual void	Reset ()
double	PIDGet ()
Static Public Attributes
static const UINT32	kOversampleBits = 10
static const UINT32	kAverageBits = 0
static const float	kSamplesPerSecond = 50.0
static const float	kCalibrationSampleTime = 5.0
static const float	kDefaultVoltsPerDegreePerSecond = 0.007

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Detailed Description

Use a rate gyro to return the robots heading relative to a starting position. The Gyro class tracks the robots heading based on the starting position. As the robot rotates the new heading is computed by integrating the rate of rotation returned by the sensor. When the class is instantiated, it does a short calibration routine where it samples the gyro while at rest to determine the default offset. This is subtracted from each sample to determine the heading. This gyro class must be used with a channel that is assigned one of the Analog accumulators from the FPGA. See AnalogChannel for the current accumulator assignments.

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Constructor & Destructor Documentation

Gyro::Gyro	(	UINT8	moduleNumber,
		UINT32	channel
	)

Gyro constructor given a slot and a channel.

Parameters:

moduleNumber	The analog module the gyro is connected to (1).
channel	The analog channel the gyro is connected to (1 or 2).

Gyro::Gyro

(

UINT32

channel

)

[explicit]

Gyro constructor with only a channel.

Use the default analog module slot.

Parameters:

channel

The analog channel the gyro is connected to.

Gyro::Gyro

(

AnalogChannel *

channel

)

[explicit]

Gyro constructor with a precreated analog channel object. Use this constructor when the analog channel needs to be shared. There is no reference counting when an AnalogChannel is passed to the gyro.

Parameters:

channel

The AnalogChannel object that the gyro is connected to.

Gyro::~Gyro

(

)

[virtual]

Delete (free) the accumulator and the analog components used for the gyro.

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Member Function Documentation

float Gyro::GetAngle

(

void

)

[virtual]

Return the actual angle in degrees that the robot is currently facing.

The angle is based on the current accumulator value corrected by the oversampling rate, the gyro type and the A/D calibration values. The angle is continuous, that is can go beyond 360 degrees. This make algorithms that wouldn't want to see a discontinuity in the gyro output as it sweeps past 0 on the second time around.

Returns:

the current heading of the robot in degrees. This heading is based on integration of the returned rate from the gyro.

Reimplemented in SendableGyro.

double Gyro::PIDGet

(

)

[virtual]

Get the angle in degrees for the PIDSource base object.

Returns:

The angle in degrees.

Implements PIDSource.

void Gyro::Reset

(

)

[virtual]

Reset the gyro. Resets the gyro to a heading of zero. This can be used if there is significant drift in the gyro and it needs to be recalibrated after it has been running.

Reimplemented in SendableGyro.

void Gyro::SetSensitivity

(

float

voltsPerDegreePerSecond

)

Set the gyro type based on the sensitivity. This takes the number of volts/degree/second sensitivity of the gyro and uses it in subsequent calculations to allow the code to work with multiple gyros.

Parameters:

voltsPerDegreePerSecond

The type of gyro specified as the voltage that represents one degree/second.

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The documentation for this class was generated from the following files:

• Gyro.h
• Gyro.cpp