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frc::AnalogGyro Class Reference

Use a rate gyro to return the robots heading relative to a starting position. More...

#include <AnalogGyro.h>

Inheritance diagram for frc::AnalogGyro:
frc::GyroBase frc::Gyro frc::ErrorBase frc::SendableBase frc::PIDSource frc::Sendable

Public Member Functions

 AnalogGyro (int channel)
 Gyro constructor using the Analog Input channel number. More...
 
 AnalogGyro (AnalogInput *channel)
 Gyro constructor with a precreated AnalogInput object. More...
 
 AnalogGyro (std::shared_ptr< AnalogInput > channel)
 Gyro constructor with a precreated AnalogInput object. More...
 
 AnalogGyro (int channel, int center, double offset)
 Gyro constructor using the Analog Input channel number with parameters for presetting the center and offset values. More...
 
 AnalogGyro (std::shared_ptr< AnalogInput > channel, int center, double offset)
 Gyro constructor with a precreated AnalogInput object and calibrated parameters. More...
 
 AnalogGyro (AnalogGyro &&rhs)
 
AnalogGyrooperator= (AnalogGyro &&rhs)
 
double GetAngle () const override
 Return the actual angle in degrees that the robot is currently facing. More...
 
double GetRate () const override
 Return the rate of rotation of the gyro. More...
 
virtual int GetCenter () const
 Return the gyro center value. More...
 
virtual double GetOffset () const
 Return the gyro offset value. More...
 
void SetSensitivity (double voltsPerDegreePerSecond)
 Set the gyro sensitivity. More...
 
void SetDeadband (double volts)
 Set the size of the neutral zone. More...
 
void Reset () override
 Reset the gyro. More...
 
virtual void InitGyro ()
 Initialize the gyro. More...
 
void Calibrate () override
 Calibrate the gyro by running for a number of samples and computing the center value. More...
 
- Public Member Functions inherited from frc::GyroBase
 GyroBase (GyroBase &&)=default
 
GyroBaseoperator= (GyroBase &&)=default
 
double PIDGet () override
 Get the PIDOutput for the PIDSource base object. More...
 
void InitSendable (SendableBuilder &builder) override
 Initializes this Sendable object. More...
 
- Public Member Functions inherited from frc::Gyro
 Gyro (Gyro &&)=default
 
Gyrooperator= (Gyro &&)=default
 
- Public Member Functions inherited from frc::ErrorBase
 ErrorBase (ErrorBase &&)=default
 
ErrorBaseoperator= (ErrorBase &&)=default
 
virtual ErrorGetError ()
 Retrieve the current error. More...
 
virtual const ErrorGetError () const
 Retrieve the current error. More...
 
virtual void ClearError () const
 Clear the current error information associated with this sensor.
 
virtual void SetErrnoError (const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber) const
 Set error information associated with a C library call that set an error to the "errno" global variable. More...
 
virtual void SetImaqError (int success, const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber) const
 Set the current error information associated from the nivision Imaq API. More...
 
virtual void SetError (Error::Code code, const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber) const
 Set the current error information associated with this sensor. More...
 
virtual void SetErrorRange (Error::Code code, int32_t minRange, int32_t maxRange, int32_t requestedValue, const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber) const
 Set the current error information associated with this sensor. More...
 
virtual void SetWPIError (const wpi::Twine &errorMessage, Error::Code code, const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber) const
 Set the current error information associated with this sensor. More...
 
virtual void CloneError (const ErrorBase &rhs) const
 
virtual bool StatusIsFatal () const
 Check if the current error code represents a fatal error. More...
 
- Public Member Functions inherited from frc::SendableBase
 SendableBase (bool addLiveWindow=true)
 Creates an instance of the sensor base. More...
 
 SendableBase (SendableBase &&rhs)
 
SendableBaseoperator= (SendableBase &&rhs)
 
std::string GetName () const final
 Gets the name of this Sendable object. More...
 
void SetName (const wpi::Twine &name) final
 Sets the name of this Sendable object. More...
 
std::string GetSubsystem () const final
 Gets the subsystem name of this Sendable object. More...
 
void SetSubsystem (const wpi::Twine &subsystem) final
 Sets the subsystem name of this Sendable object. More...
 
- Public Member Functions inherited from frc::Sendable
 Sendable (Sendable &&)=default
 
Sendableoperator= (Sendable &&)=default
 
void SetName (const wpi::Twine &subsystem, const wpi::Twine &name)
 Sets both the subsystem name and device name of this Sendable object. More...
 
- Public Member Functions inherited from frc::PIDSource
virtual void SetPIDSourceType (PIDSourceType pidSource)
 Set which parameter you are using as a process control variable. More...
 
virtual PIDSourceType GetPIDSourceType () const
 

Static Public Attributes

static constexpr int kOversampleBits = 10
 
static constexpr int kAverageBits = 0
 
static constexpr double kSamplesPerSecond = 50.0
 
static constexpr double kCalibrationSampleTime = 5.0
 
static constexpr double kDefaultVoltsPerDegreePerSecond = 0.007
 

Protected Attributes

std::shared_ptr< AnalogInputm_analog
 
- Protected Attributes inherited from frc::ErrorBase
Error m_error
 
- Protected Attributes inherited from frc::PIDSource
PIDSourceType m_pidSource = PIDSourceType::kDisplacement
 

Additional Inherited Members

- Static Public Member Functions inherited from frc::ErrorBase
static void SetGlobalError (Error::Code code, const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber)
 
static void SetGlobalWPIError (const wpi::Twine &errorMessage, const wpi::Twine &contextMessage, wpi::StringRef filename, wpi::StringRef function, int lineNumber)
 
static const ErrorGetGlobalError ()
 Retrieve the current global error.
 
- Protected Member Functions inherited from frc::SendableBase
void AddChild (std::shared_ptr< Sendable > child)
 Add a child component. More...
 
void AddChild (void *child)
 Add a child component. More...
 
void SetName (const wpi::Twine &moduleType, int channel)
 Sets the name of the sensor with a channel number. More...
 
void SetName (const wpi::Twine &moduleType, int moduleNumber, int channel)
 Sets the name of the sensor with a module and channel number. More...
 

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 AnalogInput for the current accumulator assignments.

This class is for gyro sensors that connect to an analog input.

Constructor & Destructor Documentation

frc::AnalogGyro::AnalogGyro ( int  channel)
explicit

Gyro constructor using the Analog Input channel number.

Parameters
channelThe analog channel the gyro is connected to. Gyros can only be used on on-board Analog Inputs 0-1.
frc::AnalogGyro::AnalogGyro ( AnalogInput channel)
explicit

Gyro constructor with a precreated AnalogInput object.

Use this constructor when the analog channel needs to be shared. This object will not clean up the AnalogInput object when using this constructor.

Gyros can only be used on on-board channels 0-1.

Parameters
channelA pointer to the AnalogInput object that the gyro is connected to.
frc::AnalogGyro::AnalogGyro ( std::shared_ptr< AnalogInput channel)
explicit

Gyro constructor with a precreated AnalogInput object.

Use this constructor when the analog channel needs to be shared. This object will not clean up the AnalogInput object when using this constructor.

Parameters
channelA pointer to the AnalogInput object that the gyro is connected to.
frc::AnalogGyro::AnalogGyro ( int  channel,
int  center,
double  offset 
)

Gyro constructor using the Analog Input channel number with parameters for presetting the center and offset values.

Bypasses calibration.

Parameters
channelThe analog channel the gyro is connected to. Gyros can only be used on on-board Analog Inputs 0-1.
centerPreset uncalibrated value to use as the accumulator center value.
offsetPreset uncalibrated value to use as the gyro offset.
frc::AnalogGyro::AnalogGyro ( std::shared_ptr< AnalogInput channel,
int  center,
double  offset 
)

Gyro constructor with a precreated AnalogInput object and calibrated parameters.

Use this constructor when the analog channel needs to be shared. This object will not clean up the AnalogInput object when using this constructor.

Parameters
channelA pointer to the AnalogInput object that the gyro is connected to.
centerPreset uncalibrated value to use as the accumulator center value.
offsetPreset uncalibrated value to use as the gyro offset.

Member Function Documentation

void frc::AnalogGyro::Calibrate ( )
overridevirtual

Calibrate the gyro by running for a number of samples and computing the center value.

Then use the center value as the Accumulator center value for subsequent measurements. It's important to make sure that the robot is not moving while the centering calculations are in progress, this is typically done when the robot is first turned on while it's sitting at rest before the competition starts.

Implements frc::Gyro.

double frc::AnalogGyro::GetAngle ( ) const
overridevirtual

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 it will continue from 360->361 degrees. This allows algorithms that wouldn't want to see a discontinuity in the gyro output as it sweeps from 360 to 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.

Implements frc::Gyro.

virtual int frc::AnalogGyro::GetCenter ( ) const
virtual

Return the gyro center value.

If run after calibration, the center value can be used as a preset later.

Returns
the current center value
virtual double frc::AnalogGyro::GetOffset ( ) const
virtual

Return the gyro offset value.

If run after calibration, the offset value can be used as a preset later.

Returns
the current offset value
double frc::AnalogGyro::GetRate ( ) const
overridevirtual

Return the rate of rotation of the gyro.

The rate is based on the most recent reading of the gyro analog value

Returns
the current rate in degrees per second

Implements frc::Gyro.

virtual void frc::AnalogGyro::InitGyro ( )
virtual

Initialize the gyro.

Calibration is handled by Calibrate().

void frc::AnalogGyro::Reset ( )
overridevirtual

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.

Implements frc::Gyro.

void frc::AnalogGyro::SetDeadband ( double  volts)

Set the size of the neutral zone.

Any voltage from the gyro less than this amount from the center is considered stationary. Setting a deadband will decrease the amount of drift when the gyro isn't rotating, but will make it less accurate.

Parameters
voltsThe size of the deadband in volts
void frc::AnalogGyro::SetSensitivity ( double  voltsPerDegreePerSecond)

Set the gyro 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. This value is typically found in the gyro datasheet.

Parameters
voltsPerDegreePerSecondThe sensitivity in Volts/degree/second

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