edu.wpi.first.wpilibj

Class AnalogGyro

java.lang.Object

edu.wpi.first.wpilibj.SensorBase

edu.wpi.first.wpilibj.GyroBase

edu.wpi.first.wpilibj.AnalogGyro

All Implemented Interfaces:

Gyro, LiveWindowSendable, PIDSource, Sendable

public class AnalogGyro
extends GyroBase
implements Gyro, PIDSource, LiveWindowSendable

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

Field Summary

Fields

Modifier and Type	Field and Description
protected AnalogInput	m_analog

Fields inherited from class edu.wpi.first.wpilibj.SensorBase

kAnalogInputChannels, kAnalogOutputChannels, kDigitalChannels, kPCMModules, kPDPChannels, kPDPModules, kPwmChannels, kRelayChannels, kSolenoidChannels, kSystemClockTicksPerMicrosecond

Constructor Summary

Constructors

Constructor and Description
AnalogGyro(AnalogInput channel) Gyro constructor with a precreated analog channel object.
AnalogGyro(AnalogInput channel, int center, double offset) Gyro constructor with a precreated analog channel object along with parameters for presetting the center and offset values.
AnalogGyro(int channel) Gyro constructor using the channel number
AnalogGyro(int channel, int center, double offset) Gyro constructor using the channel number along with parameters for presetting the center and offset values.

Method Summary

Modifier and Type	Method and Description
void	calibrate() Calibrate the gyro by running for a number of samples and computing the center value.
void	free() Delete (free) the accumulator and the analog components used for the gyro.
double	getAngle() Return the actual angle in degrees that the robot is currently facing.
int	getCenter() Return the gyro center value set during calibration to use as a future preset.
double	getOffset() Return the gyro offset value set during calibration to use as a future preset.
double	getRate() Return the rate of rotation of the gyro.
void	initGyro() Initialize the gyro.
void	reset() Reset the gyro.
void	setSensitivity(double voltsPerDegreePerSecond) Set the gyro sensitivity.

Methods inherited from class edu.wpi.first.wpilibj.GyroBase

getPIDSourceType, getSmartDashboardType, getTable, initTable, pidGet, setPIDSourceType, startLiveWindowMode, stopLiveWindowMode, updateTable

Methods inherited from class edu.wpi.first.wpilibj.SensorBase

checkAnalogInputChannel, checkAnalogOutputChannel, checkDigitalChannel, checkPDPChannel, checkPDPModule, checkPWMChannel, checkRelayChannel, checkSolenoidChannel, checkSolenoidModule, getDefaultSolenoidModule, setDefaultSolenoidModule

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface edu.wpi.first.wpilibj.PIDSource

getPIDSourceType, pidGet, setPIDSourceType

Methods inherited from interface edu.wpi.first.wpilibj.livewindow.LiveWindowSendable

startLiveWindowMode, stopLiveWindowMode, updateTable

Methods inherited from interface edu.wpi.first.wpilibj.Sendable

getSmartDashboardType, getTable, initTable

Field Detail

m_analog

protected AnalogInput m_analog

Constructor Detail

AnalogGyro

public AnalogGyro(int channel)

Gyro constructor using the channel number

Parameters:

channel - The analog channel the gyro is connected to. Gyros can only be used on on-board channels 0-1.

AnalogGyro

public AnalogGyro(AnalogInput channel)

Gyro constructor with a precreated analog channel object. Use this constructor when the analog channel needs to be shared.

Parameters:

channel - The AnalogInput object that the gyro is connected to. Gyros can only be used on on-board channels 0-1.

AnalogGyro

public AnalogGyro(int channel,
                  int center,
                  double offset)

Gyro constructor using the channel number along with parameters for presetting the center and offset values. Bypasses calibration.

Parameters:

channel - The analog channel the gyro is connected to. Gyros can only be used on on-board channels 0-1.

center - Preset uncalibrated value to use as the accumulator center value.

offset - Preset uncalibrated value to use as the gyro offset.

AnalogGyro

public AnalogGyro(AnalogInput channel,
                  int center,
                  double offset)

Gyro constructor with a precreated analog channel object along with parameters for presetting the center and offset values. Bypasses calibration.

Parameters:

channel - The analog channel the gyro is connected to. Gyros can only be used on on-board channels 0-1.

center - Preset uncalibrated value to use as the accumulator center value.

offset - Preset uncalibrated value to use as the gyro offset.

Method Detail

initGyro

public void initGyro()

Initialize the gyro. Calibration is handled by calibrate().

calibrate

public void calibrate()

Description copied from interface: Gyro

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.

Specified by:

calibrate in interface Gyro

reset

public void reset()

Description copied from interface: Gyro

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.

Specified by:

reset in interface Gyro

free

public void free()

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

Specified by:

free in interface Gyro

Overrides:

free in class SensorBase

getAngle

public double getAngle()

Description copied from interface: Gyro

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 to 361 degrees. This allows algorithms that wouldn't want to see a discontinuity in the gyro output as it sweeps past from 360 to 0 on the second time around.

This heading is based on integration of the returned rate from the gyro.

Specified by:

getAngle in interface Gyro

Returns:

the current heading of the robot in degrees.

getRate

public double getRate()

Description copied from interface: Gyro

Return the rate of rotation of the gyro.

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

Specified by:

getRate in interface Gyro

Returns:

the current rate in degrees per second

getOffset

public double getOffset()

Return the gyro offset value set during calibration to use as a future preset.

Returns:

the current offset value

getCenter

public int getCenter()

Return the gyro center value set during calibration to use as a future preset.

Returns:

the current center value

setSensitivity

public void 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:

voltsPerDegreePerSecond - The sensitivity in Volts/degree/second.