Ultrasonic Class Reference

#include <Ultrasonic.h>

Inheritance diagram for Ultrasonic:

Public Types
enum	DistanceUnit { kInches = 0, kMilliMeters = 1 }
Public Types inherited from PIDSource
enum	PIDSourceParameter { kDistance, kRate, kAngle }

Public Member Functions
	Ultrasonic (DigitalOutput *pingChannel, DigitalInput *echoChannel, DistanceUnit units=kInches)
	Ultrasonic (DigitalOutput &pingChannel, DigitalInput &echoChannel, DistanceUnit units=kInches)
	Ultrasonic (uint32_t pingChannel, uint32_t echoChannel, DistanceUnit units=kInches)
	Ultrasonic (uint8_t pingModuleNumber, uint32_t pingChannel, uint8_t echoModuleNumber, uint32_t echoChannel, DistanceUnit units=kInches)
virtual	~Ultrasonic ()
void	Ping ()
bool	IsRangeValid ()
double	GetRangeInches ()
double	GetRangeMM ()
bool	IsEnabled ()
void	SetEnabled (bool enable)
double	PIDGet ()
void	SetDistanceUnits (DistanceUnit units)
DistanceUnit	GetDistanceUnits ()
void	UpdateTable ()
void	StartLiveWindowMode ()
void	StopLiveWindowMode ()
std::string	GetSmartDashboardType ()
void	InitTable (ITable *subTable)
ITable *	GetTable ()
Public Member Functions inherited from SensorBase
	SensorBase ()
virtual	~SensorBase ()
Public Member Functions inherited from ErrorBase
virtual Error &	GetError ()
	Retrieve the current error. Get the current error information associated with this sensor.
virtual const Error &	GetError () const
virtual void	SetErrnoError (const char *contextMessage, const char *filename, const char *function, uint32_t 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 char *contextMessage, const char *filename, const char *function, uint32_t lineNumber) const
	Set the current error information associated from the nivision Imaq API. More...
virtual void	SetError (Error::Code code, const char *contextMessage, const char *filename, const char *function, uint32_t lineNumber) const
	Set the current error information associated with this sensor. More...
virtual void	SetWPIError (const char *errorMessage, const char *contextMessage, const char *filename, const char *function, uint32_t lineNumber) const
	Set the current error information associated with this sensor. More...
virtual void	CloneError (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...

Static Public Member Functions
static void	SetAutomaticMode (bool enabling)
Static Public Member Functions inherited from SensorBase
static void	DeleteSingletons ()
static uint32_t	GetDefaultAnalogModule ()
static uint32_t	GetDefaultDigitalModule ()
static uint32_t	GetDefaultSolenoidModule ()
static bool	CheckAnalogModule (uint8_t moduleNumber)
static bool	CheckDigitalModule (uint8_t moduleNumber)
static bool	CheckPWMModule (uint8_t moduleNumber)
static bool	CheckRelayModule (uint8_t moduleNumber)
static bool	CheckSolenoidModule (uint8_t moduleNumber)
static bool	CheckDigitalChannel (uint32_t channel)
static bool	CheckRelayChannel (uint32_t channel)
static bool	CheckPWMChannel (uint32_t channel)
static bool	CheckAnalogChannel (uint32_t channel)
static bool	CheckSolenoidChannel (uint32_t channel)
Static Public Member Functions inherited from ErrorBase
static void	SetGlobalError (Error::Code code, const char *contextMessage, const char *filename, const char *function, uint32_t lineNumber)
static void	SetGlobalWPIError (const char *errorMessage, const char *contextMessage, const char *filename, const char *function, uint32_t lineNumber)
static Error &	GetGlobalError ()

Additional Inherited Members
Static Public Attributes inherited from SensorBase
static const uint32_t	kSystemClockTicksPerMicrosecond = 40
static const uint32_t	kDigitalChannels = 14
static const uint32_t	kAnalogChannels = 8
static const uint32_t	kAnalogModules = 2
static const uint32_t	kDigitalModules = 2
static const uint32_t	kSolenoidChannels = 8
static const uint32_t	kSolenoidModules = 2
static const uint32_t	kPwmChannels = 10
static const uint32_t	kRelayChannels = 8
static const uint32_t	kChassisSlots = 8
Protected Member Functions inherited from SensorBase
void	AddToSingletonList ()
Protected Member Functions inherited from ErrorBase
	ErrorBase ()
	Initialize the instance status to 0 for now.
Protected Attributes inherited from ErrorBase
Error	m_error
Static Protected Attributes inherited from ErrorBase
static SEM_ID	_globalErrorMutex = semMCreate(SEM_Q_PRIORITY | SEM_DELETE_SAFE | SEM_INVERSION_SAFE)
static Error	_globalError

Detailed Description

Ultrasonic rangefinder class. The Ultrasonic rangefinder measures absolute distance based on the round-trip time of a ping generated by the controller. These sensors use two transducers, a speaker and a microphone both tuned to the ultrasonic range. A common ultrasonic sensor, the Daventech SRF04 requires a short pulse to be generated on a digital channel. This causes the chirp to be emmitted. A second line becomes high as the ping is transmitted and goes low when the echo is received. The time that the line is high determines the round trip distance (time of flight).

Constructor & Destructor Documentation

Ultrasonic::Ultrasonic	(	DigitalOutput *	pingChannel,
		DigitalInput *	echoChannel,
		DistanceUnit	units = kInches
	)

Create an instance of an Ultrasonic Sensor from a DigitalInput for the echo channel and a DigitalOutput for the ping channel.

Parameters

pingChannel	The digital output object that starts the sensor doing a ping. Requires a 10uS pulse to start.
echoChannel	The digital input object that times the return pulse to determine the range.
units	The units returned in either kInches or kMilliMeters

Ultrasonic::Ultrasonic	(	DigitalOutput &	pingChannel,
		DigitalInput &	echoChannel,
		DistanceUnit	units = kInches
	)

Create an instance of an Ultrasonic Sensor from a DigitalInput for the echo channel and a DigitalOutput for the ping channel.

Parameters

pingChannel	The digital output object that starts the sensor doing a ping. Requires a 10uS pulse to start.
echoChannel	The digital input object that times the return pulse to determine the range.
units	The units returned in either kInches or kMilliMeters

Ultrasonic::Ultrasonic	(	uint32_t	pingChannel,
		uint32_t	echoChannel,
		DistanceUnit	units = kInches
	)

Create an instance of the Ultrasonic Sensor using the default module. This is designed to supchannel the Daventech SRF04 and Vex ultrasonic sensors. This constructor assumes that both digital I/O channels are in the default digital module.

Parameters

pingChannel	The digital output channel that sends the pulse to initiate the sensor sending the ping.
echoChannel	The digital input channel that receives the echo. The length of time that the echo is high represents the round trip time of the ping, and the distance.
units	The units returned in either kInches or kMilliMeters

Ultrasonic::Ultrasonic	(	uint8_t	pingModuleNumber,
		uint32_t	pingChannel,
		uint8_t	echoModuleNumber,
		uint32_t	echoChannel,
		DistanceUnit	units = kInches
	)

Create an instance of the Ultrasonic sensor using specified modules. This is designed to supchannel the Daventech SRF04 and Vex ultrasonic sensors. This constructors takes the channel and module slot for each of the required digital I/O channels.

Parameters

pingModuleNumber	The digital module that the pingChannel is on.
pingChannel	The digital output channel that sends the pulse to initiate the sensor sending the ping.
echoModuleNumber	The digital module that the echoChannel is on.
echoChannel	The digital input channel that receives the echo. The length of time that the echo is high represents the round trip time of the ping, and the distance.
units	The units returned in either kInches or kMilliMeters

Ultrasonic::~Ultrasonic ( )

virtual

Destructor for the ultrasonic sensor. Delete the instance of the ultrasonic sensor by freeing the allocated digital channels. If the system was in automatic mode (round robin), then it is stopped, then started again after this sensor is removed (provided this wasn't the last sensor).

Member Function Documentation

Ultrasonic::DistanceUnit Ultrasonic::GetDistanceUnits

(

)

Get the current DistanceUnit that is used for the PIDSource base object.

Returns

The type of DistanceUnit that is being used.

double Ultrasonic::GetRangeInches

(

)

Get the range in inches from the ultrasonic sensor.

Returns

double Range in inches of the target returned from the ultrasonic sensor. If there is no valid value yet, i.e. at least one measurement hasn't completed, then return 0.

double Ultrasonic::GetRangeMM

(

)

Get the range in millimeters from the ultrasonic sensor.

Returns

double Range in millimeters of the target returned by the ultrasonic sensor. If there is no valid value yet, i.e. at least one measurement hasn't complted, then return 0.

bool Ultrasonic::IsRangeValid

(

)

Check if there is a valid range measurement. The ranges are accumulated in a counter that will increment on each edge of the echo (return) signal. If the count is not at least 2, then the range has not yet been measured, and is invalid.

double Ultrasonic::PIDGet ( )

virtual

Get the range in the current DistanceUnit for the PIDSource base object.

Returns

The range in DistanceUnit

Implements PIDSource.

void Ultrasonic::Ping

(

)

Single ping to ultrasonic sensor. Send out a single ping to the ultrasonic sensor. This only works if automatic (round robin) mode is disabled. A single ping is sent out, and the counter should count the semi-period when it comes in. The counter is reset to make the current value invalid.

void Ultrasonic::SetAutomaticMode ( bool  enabling )

static

Turn Automatic mode on/off. When in Automatic mode, all sensors will fire in round robin, waiting a set time between each sensor.

Parameters

enabling

Set to true if round robin scheduling should start for all the ultrasonic sensors. This scheduling method assures that the sensors are non-interfering because no two sensors fire at the same time. If another scheduling algorithm is preffered, it can be implemented by pinging the sensors manually and waiting for the results to come back.

void Ultrasonic::SetDistanceUnits

(

DistanceUnit

units

)

Set the current DistanceUnit that should be used for the PIDSource base object.

Parameters

units

The DistanceUnit that should be used.

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

• Ultrasonic.h
• Ultrasonic.cpp