WPILibC++
unspecified
|
Class to read quad encoders. More...
#include <Encoder.h>
Public Types | |
enum | IndexingType { kResetWhileHigh, kResetWhileLow, kResetOnFallingEdge, kResetOnRisingEdge } |
![]() | |
enum | EncodingType { k1X, k2X, k4X } |
Public Member Functions | |
Encoder (int aChannel, int bChannel, bool reverseDirection=false, EncodingType encodingType=k4X) | |
Encoder constructor. More... | |
Encoder (std::shared_ptr< DigitalSource > aSource, std::shared_ptr< DigitalSource > bSource, bool reverseDirection=false, EncodingType encodingType=k4X) | |
Encoder (DigitalSource *aSource, DigitalSource *bSource, bool reverseDirection=false, EncodingType encodingType=k4X) | |
Encoder constructor. More... | |
Encoder (DigitalSource &aSource, DigitalSource &bSource, bool reverseDirection=false, EncodingType encodingType=k4X) | |
Encoder constructor. More... | |
virtual | ~Encoder () |
Free the resources for an Encoder. More... | |
int | Get () const override |
Gets the current count. More... | |
int | GetRaw () const |
Gets the raw value from the encoder. More... | |
int | GetEncodingScale () const |
The encoding scale factor 1x, 2x, or 4x, per the requested encodingType. More... | |
void | Reset () override |
Reset the Encoder distance to zero. More... | |
double | GetPeriod () const override |
Returns the period of the most recent pulse. More... | |
void | SetMaxPeriod (double maxPeriod) override |
Sets the maximum period for stopped detection. More... | |
bool | GetStopped () const override |
Determine if the encoder is stopped. More... | |
bool | GetDirection () const override |
The last direction the encoder value changed. More... | |
double | GetDistance () const |
Get the distance the robot has driven since the last reset. More... | |
double | GetRate () const |
Get the current rate of the encoder. More... | |
void | SetMinRate (double minRate) |
Set the minimum rate of the device before the hardware reports it stopped. More... | |
void | SetDistancePerPulse (double distancePerPulse) |
Set the distance per pulse for this encoder. More... | |
void | SetReverseDirection (bool reverseDirection) |
Set the direction sensing for this encoder. More... | |
void | SetSamplesToAverage (int samplesToAverage) |
Set the Samples to Average which specifies the number of samples of the timer to average when calculating the period. More... | |
int | GetSamplesToAverage () const |
Get the Samples to Average which specifies the number of samples of the timer to average when calculating the period. More... | |
double | PIDGet () override |
Implement the PIDSource interface. More... | |
void | SetIndexSource (int channel, IndexingType type=kResetOnRisingEdge) |
Set the index source for the encoder. More... | |
void | SetIndexSource (const DigitalSource &source, IndexingType type=kResetOnRisingEdge) |
Set the index source for the encoder. More... | |
void | UpdateTable () override |
Update the table for this sendable object with the latest values. | |
void | StartLiveWindowMode () override |
Start having this sendable object automatically respond to value changes reflect the value on the table. | |
void | StopLiveWindowMode () override |
Stop having this sendable object automatically respond to value changes. | |
std::string | GetSmartDashboardType () const override |
void | InitTable (std::shared_ptr< nt::NetworkTable > subTable) override |
Initializes a table for this sendable object. More... | |
int | GetFPGAIndex () const |
![]() | |
SensorBase (const SensorBase &)=delete | |
SensorBase & | operator= (const SensorBase &)=delete |
![]() | |
ErrorBase (const ErrorBase &)=delete | |
ErrorBase & | operator= (const ErrorBase &)=delete |
virtual Error & | GetError () |
Retrieve the current error. More... | |
virtual const Error & | GetError () const |
virtual void | SetErrnoError (llvm::StringRef contextMessage, llvm::StringRef filename, llvm::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, llvm::StringRef contextMessage, llvm::StringRef filename, llvm::StringRef function, int lineNumber) const |
Set the current error information associated from the nivision Imaq API. More... | |
virtual void | SetError (Error::Code code, llvm::StringRef contextMessage, llvm::StringRef filename, llvm::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, llvm::StringRef contextMessage, llvm::StringRef filename, llvm::StringRef function, int lineNumber) const |
Set the current error information associated with this sensor. More... | |
virtual void | SetWPIError (llvm::StringRef errorMessage, Error::Code code, llvm::StringRef contextMessage, llvm::StringRef filename, llvm::StringRef function, int lineNumber) const |
Set the current error information associated with this sensor. More... | |
virtual void | CloneError (const ErrorBase &rhs) const |
virtual void | ClearError () const |
Clear the current error information associated with this sensor. | |
virtual bool | StatusIsFatal () const |
Check if the current error code represents a fatal error. More... | |
![]() | |
virtual void | SetPIDSourceType (PIDSourceType pidSource) |
Set which parameter you are using as a process control variable. More... | |
PIDSourceType | GetPIDSourceType () const |
Friends | |
class | DigitalGlitchFilter |
Additional Inherited Members | |
![]() | |
static int | GetDefaultSolenoidModule () |
static bool | CheckSolenoidModule (int moduleNumber) |
Check that the solenoid module number is valid. More... | |
static bool | CheckDigitalChannel (int channel) |
Check that the digital channel number is valid. More... | |
static bool | CheckRelayChannel (int channel) |
Check that the relay channel number is valid. More... | |
static bool | CheckPWMChannel (int channel) |
Check that the digital channel number is valid. More... | |
static bool | CheckAnalogInputChannel (int channel) |
Check that the analog input number is value. More... | |
static bool | CheckAnalogOutputChannel (int channel) |
Check that the analog output number is valid. More... | |
static bool | CheckSolenoidChannel (int channel) |
Verify that the solenoid channel number is within limits. More... | |
static bool | CheckPDPChannel (int channel) |
Verify that the power distribution channel number is within limits. More... | |
![]() | |
static void | SetGlobalError (Error::Code code, llvm::StringRef contextMessage, llvm::StringRef filename, llvm::StringRef function, int lineNumber) |
static void | SetGlobalWPIError (llvm::StringRef errorMessage, llvm::StringRef contextMessage, llvm::StringRef filename, llvm::StringRef function, int lineNumber) |
static Error & | GetGlobalError () |
Retrieve the current global error. | |
![]() | |
static const int | kDigitalChannels = HAL_GetNumDigitalChannels() |
static const int | kAnalogInputs = HAL_GetNumAnalogInputs() |
static const int | kAnalogOutputs |
static const int | kSolenoidChannels = HAL_GetNumSolenoidChannels() |
static const int | kSolenoidModules = HAL_GetNumPCMModules() |
static const int | kPwmChannels = HAL_GetNumPWMChannels() |
static const int | kRelayChannels = HAL_GetNumRelayHeaders() |
static const int | kPDPChannels = HAL_GetNumPDPChannels() |
![]() | |
Error | m_error |
![]() | |
PIDSourceType | m_pidSource = PIDSourceType::kDisplacement |
![]() | |
static std::mutex | _globalErrorMutex |
static Error | _globalError |
Class to read quad encoders.
Quadrature encoders are devices that count shaft rotation and can sense direction. The output of the QuadEncoder class is an integer that can count either up or down, and can go negative for reverse direction counting. When creating QuadEncoders, a direction is supplied that changes the sense of the output to make code more readable if the encoder is mounted such that forward movement generates negative values. Quadrature encoders have two digital outputs, an A Channel and a B Channel that are out of phase with each other to allow the FPGA to do direction sensing.
All encoders will immediately start counting - Reset() them if you need them to be zeroed before use.
Encoder::Encoder | ( | int | aChannel, |
int | bChannel, | ||
bool | reverseDirection = false , |
||
EncodingType | encodingType = k4X |
||
) |
Encoder constructor.
Construct a Encoder given a and b channels.
The counter will start counting immediately.
aChannel | The a channel DIO channel. 0-9 are on-board, 10-25 are on the MXP port |
bChannel | The b channel DIO channel. 0-9 are on-board, 10-25 are on the MXP port |
reverseDirection | represents the orientation of the encoder and inverts the output values if necessary so forward represents positive values. |
encodingType | either k1X, k2X, or k4X to indicate 1X, 2X or 4X decoding. If 4X is selected, then an encoder FPGA object is used and the returned counts will be 4x the encoder spec'd value since all rising and falling edges are counted. If 1X or 2X are selected then a counter object will be used and the returned value will either exactly match the spec'd count or be double (2x) the spec'd count. |
Encoder::Encoder | ( | DigitalSource * | aSource, |
DigitalSource * | bSource, | ||
bool | reverseDirection = false , |
||
EncodingType | encodingType = k4X |
||
) |
Encoder constructor.
Construct a Encoder given a and b channels as digital inputs. This is used in the case where the digital inputs are shared. The Encoder class will not allocate the digital inputs and assume that they already are counted.
The counter will start counting immediately.
aSource | The source that should be used for the a channel. |
bSource | the source that should be used for the b channel. |
reverseDirection | represents the orientation of the encoder and inverts the output values if necessary so forward represents positive values. |
encodingType | either k1X, k2X, or k4X to indicate 1X, 2X or 4X decoding. If 4X is selected, then an encoder FPGA object is used and the returned counts will be 4x the encoder spec'd value since all rising and falling edges are counted. If 1X or 2X are selected then a counter object will be used and the returned value will either exactly match the spec'd count or be double (2x) the spec'd count. |
Encoder::Encoder | ( | DigitalSource & | aSource, |
DigitalSource & | bSource, | ||
bool | reverseDirection = false , |
||
EncodingType | encodingType = k4X |
||
) |
Encoder constructor.
Construct a Encoder given a and b channels as digital inputs. This is used in the case where the digital inputs are shared. The Encoder class will not allocate the digital inputs and assume that they already are counted.
The counter will start counting immediately.
aSource | The source that should be used for the a channel. |
bSource | the source that should be used for the b channel. |
reverseDirection | represents the orientation of the encoder and inverts the output values if necessary so forward represents positive values. |
encodingType | either k1X, k2X, or k4X to indicate 1X, 2X or 4X decoding. If 4X is selected, then an encoder FPGA object is used and the returned counts will be 4x the encoder spec'd value since all rising and falling edges are counted. If 1X or 2X are selected then a counter object will be used and the returned value will either exactly match the spec'd count or be double (2x) the spec'd count. |
|
virtual |
|
overridevirtual |
Gets the current count.
Returns the current count on the Encoder. This method compensates for the decoding type.
Implements frc::CounterBase.
|
overridevirtual |
The last direction the encoder value changed.
Implements frc::CounterBase.
double Encoder::GetDistance | ( | ) | const |
Get the distance the robot has driven since the last reset.
int Encoder::GetEncodingScale | ( | ) | const |
The encoding scale factor 1x, 2x, or 4x, per the requested encodingType.
Used to divide raw edge counts down to spec'd counts.
|
overridevirtual |
Returns the period of the most recent pulse.
Returns the period of the most recent Encoder pulse in seconds. This method compensates for the decoding type.
Warning: This returns unscaled periods. Use GetRate() for rates that are scaled using the value from SetDistancePerPulse().
Implements frc::CounterBase.
double Encoder::GetRate | ( | ) | const |
Get the current rate of the encoder.
Units are distance per second as scaled by the value from SetDistancePerPulse().
int Encoder::GetRaw | ( | ) | const |
Gets the raw value from the encoder.
The raw value is the actual count unscaled by the 1x, 2x, or 4x scale factor.
int Encoder::GetSamplesToAverage | ( | ) | const |
Get the Samples to Average which specifies the number of samples of the timer to average when calculating the period.
Perform averaging to account for mechanical imperfections or as oversampling to increase resolution.
|
overridevirtual |
Implements frc::Sendable.
|
overridevirtual |
Determine if the encoder is stopped.
Using the MaxPeriod value, a boolean is returned that is true if the encoder is considered stopped and false if it is still moving. A stopped encoder is one where the most recent pulse width exceeds the MaxPeriod.
Implements frc::CounterBase.
|
overridevirtual |
Initializes a table for this sendable object.
subtable | The table to put the values in. |
Implements frc::Sendable.
|
overridevirtual |
Implement the PIDSource interface.
Implements frc::PIDSource.
|
overridevirtual |
Reset the Encoder distance to zero.
Resets the current count to zero on the encoder.
Implements frc::CounterBase.
void Encoder::SetDistancePerPulse | ( | double | distancePerPulse | ) |
Set the distance per pulse for this encoder.
This sets the multiplier used to determine the distance driven based on the count value from the encoder.
Do not include the decoding type in this scale. The library already compensates for the decoding type.
Set this value based on the encoder's rated Pulses per Revolution and factor in gearing reductions following the encoder shaft.
This distance can be in any units you like, linear or angular.
distancePerPulse | The scale factor that will be used to convert pulses to useful units. |
void Encoder::SetIndexSource | ( | int | channel, |
Encoder::IndexingType | type = kResetOnRisingEdge |
||
) |
Set the index source for the encoder.
When this source is activated, the encoder count automatically resets.
channel | A DIO channel to set as the encoder index |
type | The state that will cause the encoder to reset |
void Encoder::SetIndexSource | ( | const DigitalSource & | source, |
Encoder::IndexingType | type = kResetOnRisingEdge |
||
) |
Set the index source for the encoder.
When this source is activated, the encoder count automatically resets.
channel | A digital source to set as the encoder index |
type | The state that will cause the encoder to reset |
|
overridevirtual |
Sets the maximum period for stopped detection.
Sets the value that represents the maximum period of the Encoder before it will assume that the attached device is stopped. This timeout allows users to determine if the wheels or other shaft has stopped rotating. This method compensates for the decoding type.
maxPeriod | The maximum time between rising and falling edges before the FPGA will report the device stopped. This is expressed in seconds. |
Implements frc::CounterBase.
void Encoder::SetMinRate | ( | double | minRate | ) |
Set the minimum rate of the device before the hardware reports it stopped.
minRate | The minimum rate. The units are in distance per second as scaled by the value from SetDistancePerPulse(). |
void Encoder::SetReverseDirection | ( | bool | reverseDirection | ) |
Set the direction sensing for this encoder.
This sets the direction sensing on the encoder so that it could count in the correct software direction regardless of the mounting.
reverseDirection | true if the encoder direction should be reversed |
void Encoder::SetSamplesToAverage | ( | int | samplesToAverage | ) |
Set the Samples to Average which specifies the number of samples of the timer to average when calculating the period.
Perform averaging to account for mechanical imperfections or as oversampling to increase resolution.
samplesToAverage | The number of samples to average from 1 to 127. |