#include <PWM.h>

Inheritance diagram for PWM:

Collaboration diagram for PWM:

Public Types
enum	PeriodMultiplier { kPeriodMultiplier_1X = 1, kPeriodMultiplier_2X = 2, kPeriodMultiplier_4X = 4 }

Public Member Functions
	PWM (UINT32 channel)
	PWM (UINT8 moduleNumber, UINT32 channel)
virtual	~PWM ()
virtual void	SetRaw (UINT8 value)
virtual UINT8	GetRaw ()
void	SetPeriodMultiplier (PeriodMultiplier mult)
void	EnableDeadbandElimination (bool eliminateDeadband)
void	SetBounds (INT32 max, INT32 deadbandMax, INT32 center, INT32 deadbandMin, INT32 min)
UINT32	GetChannel ()
UINT32	GetModuleNumber ()
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 lineNumber) const
	Set error information associated with a C library call that set an error to the "errno" global variable.
virtual void	SetImaqError (int success, const char contextMessage, const char filename, const char *function, UINT32 lineNumber) const
	Set the current error information associated from the nivision Imaq API.
virtual void	SetError (Error::Code code, const char contextMessage, const char filename, const char *function, UINT32 lineNumber) const
	Set the current error information associated with this sensor.
virtual void	SetWPIError (const char errorMessage, const char contextMessage, const char filename, const char function, UINT32 lineNumber) const
	Set the current error information associated with this sensor.
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.

Protected Member Functions
virtual void	SetPosition (float pos)
virtual float	GetPosition ()
virtual void	SetSpeed (float speed)
virtual float	GetSpeed ()
void	ValueChanged (ITable *source, const std::string &key, EntryValue value, bool isNew)
void	UpdateTable ()
void	StartLiveWindowMode ()
void	StopLiveWindowMode ()
std::string	GetSmartDashboardType ()
void	InitTable (ITable *subTable)
ITable *	GetTable ()
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
bool	m_eliminateDeadband
INT32	m_maxPwm
INT32	m_deadbandMaxPwm
INT32	m_centerPwm
INT32	m_deadbandMinPwm
INT32	m_minPwm
ITable *	m_table

Static Protected Attributes
static const UINT32	kDefaultPwmPeriod = 774
static const UINT32	kDefaultMinPwmHigh = 102
static const INT32	kPwmDisabled = 0

Friends
class	DigitalModule

Additional Inherited Members
Static Public Member Functions inherited from SensorBase
static void	DeleteSingletons ()
static UINT32	GetDefaultAnalogModule ()
static UINT32	GetDefaultDigitalModule ()
static UINT32	GetDefaultSolenoidModule ()
static bool	CheckAnalogModule (UINT8 moduleNumber)
static bool	CheckDigitalModule (UINT8 moduleNumber)
static bool	CheckPWMModule (UINT8 moduleNumber)
static bool	CheckRelayModule (UINT8 moduleNumber)
static bool	CheckSolenoidModule (UINT8 moduleNumber)
static bool	CheckDigitalChannel (UINT32 channel)
static bool	CheckRelayChannel (UINT32 channel)
static bool	CheckPWMChannel (UINT32 channel)
static bool	CheckAnalogChannel (UINT32 channel)
static bool	CheckSolenoidChannel (UINT32 channel)
Static Public Attributes inherited from SensorBase
static const UINT32	kSystemClockTicksPerMicrosecond = 40
static const UINT32	kDigitalChannels = 14
static const UINT32	kAnalogChannels = 8
static const UINT32	kAnalogModules = 2
static const UINT32	kDigitalModules = 2
static const UINT32	kSolenoidChannels = 8
static const UINT32	kSolenoidModules = 2
static const UINT32	kPwmChannels = 10
static const UINT32	kRelayChannels = 8
static const UINT32	kChassisSlots = 8

Detailed Description

Class implements the PWM generation in the FPGA.

The values supplied as arguments for PWM outputs range from -1.0 to 1.0. They are mapped to the hardware dependent values, in this case 0-255 for the FPGA. Changes are immediately sent to the FPGA, and the update occurs at the next FPGA cycle. There is no delay.

As of revision 0.1.10 of the FPGA, the FPGA interprets the 0-255 values as follows:

255 = full "forward"
254 to 129 = linear scaling from "full forward" to "center"
128 = center value
127 to 2 = linear scaling from "center" to "full reverse"
1 = full "reverse"
0 = disabled (i.e. PWM output is held low)

Definition at line 32 of file PWM.h.

Constructor & Destructor Documentation

PWM::PWM ( UINT32 channel )

explicit

Allocate a PWM in the default module given a channel.

Using a default module allocate a PWM given the channel number. The default module is the first slot numerically in the cRIO chassis.

Parameters

channel The PWM channel on the digital module.

Definition at line 79 of file PWM.cpp.

PWM::PWM	(	UINT8	moduleNumber,
		UINT32	channel
	)

Allocate a PWM given a module and channel. Allocate a PWM using a module and channel number.

Parameters

moduleNumber	The digital module (1 or 2).
channel	The PWM channel on the digital module (1..10).

Definition at line 65 of file PWM.cpp.

PWM::~PWM ( )

virtual

Free the PWM channel.

Free the resource associated with the PWM channel and set the value to 0.

Definition at line 90 of file PWM.cpp.

Member Function Documentation

void PWM::EnableDeadbandElimination ( bool eliminateDeadband )

Optionally eliminate the deadband from a speed controller.

Parameters

eliminateDeadband If true, set the motor curve on the Jaguar to eliminate the deadband in the middle of the range. Otherwise, keep the full range without modifying any values.

Definition at line 105 of file PWM.cpp.

float PWM::GetPosition ( )

protectedvirtual

Get the PWM value in terms of a position.

This is intended to be used by servos.

Precondition: SetMaxPositivePwm() called.; SetMinNegativePwm() called.

Returns: The position the servo is set to between 0.0 and 1.0.

Definition at line 179 of file PWM.cpp.

UINT8 PWM::GetRaw ( )

virtual

Get the PWM value directly from the hardware.

Read a raw value from a PWM channel.

Returns: Raw PWM control value. Range: 0 - 255.

Definition at line 306 of file PWM.cpp.

std::string PWM::GetSmartDashboardType ( )

protectedvirtual

Returns: the string representation of the named data type that will be used by the smart dashboard for this sendable

Implements Sendable.

Reimplemented in Servo.

Definition at line 356 of file PWM.cpp.

float PWM::GetSpeed ( )

protectedvirtual

Get the PWM value in terms of speed.

This is intended to be used by speed controllers.

Precondition: SetMaxPositivePwm() called.; SetMinPositivePwm() called.; SetMaxNegativePwm() called.; SetMinNegativePwm() called.

Returns: The most recently set speed between -1.0 and 1.0.

Definition at line 260 of file PWM.cpp.

ITable * PWM::GetTable ( )

protectedvirtual

Returns: the table that is currently associated with the sendable

Implements Sendable.

Reimplemented in Servo.

Definition at line 365 of file PWM.cpp.

void PWM::InitTable ( ITable * subtable )

protectedvirtual

Initializes a table for this sendable object.

Parameters

subtable The table to put the values in.

Implements Sendable.

Reimplemented in Servo.

Definition at line 360 of file PWM.cpp.

void PWM::SetBounds	(	INT32	max,
		INT32	deadbandMax,
		INT32	center,
		INT32	deadbandMin,
		INT32	min
	)

Set the bounds on the PWM values. This sets the bounds on the PWM values for a particular each type of controller. The values determine the upper and lower speeds as well as the deadband bracket.

Parameters

max	The Minimum pwm value
deadbandMax	The high end of the deadband range
center	The center speed (off)
deadbandMin	The low end of the deadband range
min	The minimum pwm value

Definition at line 121 of file PWM.cpp.

void PWM::SetPeriodMultiplier ( PeriodMultiplier mult )

Slow down the PWM signal for old devices.

Parameters

mult	The period multiplier to apply to this channel

Definition at line 317 of file PWM.cpp.

void PWM::SetPosition ( float pos )

protectedvirtual

Set the PWM value based on a position.

This is intended to be used by servos.

Precondition: SetMaxPositivePwm() called.; SetMinNegativePwm() called.

Parameters

pos	The position to set the servo between 0.0 and 1.0.

Definition at line 146 of file PWM.cpp.

void PWM::SetRaw ( UINT8 value )

virtual

Set the PWM value directly to the hardware.

Write a raw value to a PWM channel.

Parameters

value Raw PWM value. Range 0 - 255.

Definition at line 293 of file PWM.cpp.

void PWM::SetSpeed ( float speed )

protectedvirtual

Set the PWM value based on a speed.

This is intended to be used by speed controllers.

Precondition: SetMaxPositivePwm() called.; SetMinPositivePwm() called.; SetCenterPwm() called.; SetMaxNegativePwm() called.; SetMinNegativePwm() called.

Parameters

speed The speed to set the speed controller between -1.0 and 1.0.

Reimplemented in SafePWM.

Definition at line 210 of file PWM.cpp.

void PWM::StartLiveWindowMode ( )

protectedvirtual

Start having this sendable object automatically respond to value changes reflect the value on the table.

Implements LiveWindowSendable.

Reimplemented in Servo.

Definition at line 347 of file PWM.cpp.

void PWM::StopLiveWindowMode ( )

protectedvirtual

Stop having this sendable object automatically respond to value changes.

Implements LiveWindowSendable.

Reimplemented in Servo.

Definition at line 351 of file PWM.cpp.

void PWM::UpdateTable ( )

protectedvirtual

Update the table for this sendable object with the latest values.

Implements LiveWindowSendable.

Reimplemented in Servo.

Definition at line 341 of file PWM.cpp.

void PWM::ValueChanged	(	ITable *	source,
		const std::string &	key,
		EntryValue	value,
		bool	isNew
	)

protectedvirtual

Called when a key-value pair is changed in a ITable WARNING: If a new key-value is put in this method value changed will immediatly be called which could lead to recursive code

Parameters

source	the table the key-value pair exists in
key	the key associated with the value that changed
value	the new value
isNew	true if the key did not previously exist in the table, otherwise it is false

Implements ITableListener.

Reimplemented in Servo.

Definition at line 337 of file PWM.cpp.

Member Data Documentation

const UINT32 PWM::kDefaultMinPwmHigh = 102

staticprotected

kDefaultMinPwmHigh is "ticks" where each tick is 6.525us

There are 128 pwm values less than the center, so...
The minimum output pulse length is 1.5ms - 128 * 6.525us = 0.665ms
0.665ms / 6.525us per tick = 102

Definition at line 77 of file PWM.h.

const UINT32 PWM::kDefaultPwmPeriod = 774

staticprotected

kDefaultPwmPeriod is "ticks" where each tick is 6.525us

20ms periods (50 Hz) are the "safest" setting in that this works for all devices
20ms periods seem to be desirable for Vex Motors
20ms periods are the specified period for HS-322HD servos, but work reliably down to 10.0 ms; starting at about 8.5ms, the servo sometimes hums and get hot; by 5.0ms the hum is nearly continuous
10ms periods work well for Victor 884
5ms periods allows higher update rates for Luminary Micro Jaguar speed controllers. Due to the shipping firmware on the Jaguar, we can't run the update period less than 5.05 ms.

kDefaultPwmPeriod is the 1x period (5.05 ms). In hardware, the period scaling is implemented as an output squelch to get longer periods for old devices.

Set to 5.05 ms period / 6.525us clock = 774

Definition at line 68 of file PWM.h.

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

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation