MityDSP::tcDspTouchScreen Class Reference

The tcDspTouchScreen class provides access to a 4-wire touch screen overlay device. More...

#include <core/DspTouchScreen.h>

Public Types
enum	teEventType { eeNoEvent, eePenDown, eeDataChange }
Public Member Functions
	tcDspTouchScreen (void *apAddress, unsigned int anScreenWidth, unsigned int anScreenHeight, SEM_Handle ahTouchSem=NULL, bool abRotate=false)
	This constructor is used to create an instance of the tcDspTouchScreen class.
	~tcDspTouchScreen ()
	This destructor is used to close up and free tcDspTouchScreen resources.
bool	IsTouched (void)
	This routine indicates whether or not the touch screen overlay is currently "touched".
void	EventEnable (teEventType aeEvent)
	This routine enables posting of the user semaphore on pen down or data change events.
void	Rotate (bool abRotate)
	Enables or disables 90 degree touch screen rotation.
bool	IsRotated (void)
	Indicates whether touch screen is currently rotated 90 degrees.
bool	GetPosition (tcDspDisplay::tsScreenCoords &arPos)
	This routine obtains the most recent touch screen controller ADC values, applies the current calibration, and returns the touch position in screen pixel coordinates (origin at upper left).
bool	GetPositionRaw (tcDspDisplay::tsScreenCoords &arCounts)
	This routine reads the most recent touch screen controller ADC values.
void	SetCalParams (tcDspDisplay::tsScreenCoords asCalUL, tcDspDisplay::tsScreenCoords asCalLR)
	This routine provides new calibration parameters to this instance of tcDspTouchScreen.
void	GetCalParams (tcDspDisplay::tsScreenCoords &arCalUL, tcDspDisplay::tsScreenCoords &arCalLR)
	This routine returns the calibration parameters in use by this instance of tcDspTouchScreen.
bool	CalUpperLeft (int anTimeoutMsec)
	This is a convenience routine to assist with calibration.
bool	CalLowerRight (int anTimeoutMsec)
	This is a convenience routine to assist with calibration.
SEM_Handle	GetTouchSem (void)
	Utility routine to get the active associated semaphore handle used for Touch notifications.
void	SetTouchSem (SEM_Handle ahTouchSem)
	Utility routine to set the active associated semaphore handle used for Touch notifications.
void	EnableGPIO (bool abEnable)
	Call this routine to enable continuous polling of the GPIO input data.
bool	IsGPIOEnabled (void)
	Returns the enabled state from EnableGPIO().
void	SetOutput (unsigned int anMask, unsigned int anValue)
	Set the output state of the GPIO pins attached to the display SPI controller.
unsigned int	GetInputs (unsigned int anMask)
	Gets the most recently polled GPIO Input state from the GPIO devices attached to the display SPI controller.
int	SendDispCommand (unsigned int anCommand, SEM_Handle ahDoneSem)
	Send an SPI Command to an attached display SPI controller.
unsigned int	GetDispResponse (void)
	Retrieve response from an SPI Command issued to an attached display SPI controller.
Public Attributes
unsigned int	mnInterruptCount
	ISR counter (debug).
Static Public Attributes
static const int	gnMinAdcValue = 0
	minimum controller ADC value
static const int	gnMaxAdcValue = 4095
	full-scale controller ADC value
Protected Member Functions
void	TouchInterrupt (void)
	Interrupt service routine for the TouchScreen core.
Static Protected Member Functions
static int	interrupt_dispatch (Arg arMyObject)
	Static interrupt dispatch routine.
Protected Attributes
LCK_Handle	mhMutex
	Used to serialize access.
volatile unsigned int *	mpBaseAddr
	TouchScreen base address.
unsigned short	mnMyIntMask
	TouchScreen interrupt mask.
int	mnMyIntLevel
	TouchScreen interrupt level.
int	mnMyIntVector
	TouchScreen interrupt vector.
SEM_Handle	mhTouchSemaphore
	Storage for touch/untouch semaphore.
SEM_Handle	mhTmpTouch
	Temporarily take over "touched" semaphore.
int	mnWidthPixels
	Pixel width of display.
int	mnHeightPixels
	Pixel height of display.
bool	mbRotate
	If true, X and Y axes are reversed.
tcDspDisplay::tsScreenCoords	msCalUL
	Controller ADC values at screen upper left.
tcDspDisplay::tsScreenCoords	msCalLR
	Controller ADC values at screen lower right.
teEventType	meEvent
	Type of event to interrupt upon.
volatile SEM_Handle	mhCommandDoneSem
	option semaphore to post when command is completed resp ready
Static Protected Attributes
static unsigned int	mnTicksPerMsec = CLK_countspms() / CLK_getprd()
	Number of clocks per millisecond.

Detailed Description

The tcDspTouchScreen class provides access to a 4-wire touch screen overlay device.

A semaphore is posted every time the screen is touched. A pair of functions are provided to assist with calibration.

See also:: tcDspTouchScreen Page

Member Enumeration Documentation

enum MityDSP::tcDspTouchScreen::teEventType

Enumerator:

eeNoEvent
eePenDown
eeDataChange

Constructor & Destructor Documentation

tcDspTouchScreen::tcDspTouchScreen	(	void *	apAddress,
		unsigned int	anScreenWidth,
		unsigned int	anScreenHeight,
		SEM_Handle	ahTouchSem = `NULL`,
		bool	abRotate = `false`
	)

This constructor is used to create an instance of the tcDspTouchScreen class.

The address of the core, screen dimensions, and a semaphore handle (for screen touch and/or data change events) must be provided.

Parameters:

`[in]`	apAddress	Base Address of the Touch Screen controller core.
`[in]`	anScreenWidth	Screen width, in pixels.
`[in]`	anScreenHeight	Screen height, in pixels.
`[in]`	ahTouchSem	User-semaphore to associate with screen events.
`[in]`	abRotate	Set to true to use a vertically oriented touch screen with a horizontally oriented display or vice versa.

Returns:: None.

See also:: DspTouchScreen.h

tcDspTouchScreen::~tcDspTouchScreen ( )

This destructor is used to close up and free tcDspTouchScreen resources.

Returns:: None.

See also:: DspTouchScreen.h

Member Function Documentation

bool tcDspTouchScreen::IsTouched ( void )

This routine indicates whether or not the touch screen overlay is currently "touched".

Returns:: True if screen is currently "touched".

See also:: DspTouchScreen.h

void tcDspTouchScreen::EventEnable ( teEventType aeEvent )

This routine enables posting of the user semaphore on pen down or data change events.

Parameters:

[in]

aeEvent

Type of event to set user semaphore upon:

eeNoEvent No events
eePenDown Whenever screen becomes "touched"
eeDataChange Whenever data changes

Returns:: None.

See also:: DspTouchScreen.h

void tcDspTouchScreen::Rotate ( bool abRotate )

Enables or disables 90 degree touch screen rotation.

Note:: Touch screen must be recalibrated following a change in rotation.

Parameters:

[in] abRotate If true, rotates screen coordinates 90-degrees.

Returns:: None.

See also:: DspTouchScreen.h

bool tcDspTouchScreen::IsRotated ( void )

Indicates whether touch screen is currently rotated 90 degrees.

Returns:: True if rotated.

See also:: DspTouchScreen.h

bool tcDspTouchScreen::GetPosition ( tcDspDisplay::tsScreenCoords & arPos )

This routine obtains the most recent touch screen controller ADC values, applies the current calibration, and returns the touch position in screen pixel coordinates (origin at upper left).

Parameters:

[out] arPos Storage for screen position results (pixels relative to upper left corner of display).

Returns:: True if successful.

See also:: DspTouchScreen.h

bool tcDspTouchScreen::GetPositionRaw ( tcDspDisplay::tsScreenCoords & arCounts )

This routine reads the most recent touch screen controller ADC values.

Parameters:

[out] arCounts Storage for ADC count results (width and length axis values).

Returns:: True if screen is currently "touched".

See also:: DspTouchScreen.h

void tcDspTouchScreen::SetCalParams	(	tcDspDisplay::tsScreenCoords	asCalUL,
		tcDspDisplay::tsScreenCoords	asCalLR
	)

This routine provides new calibration parameters to this instance of tcDspTouchScreen.

This supports performing calibration manually, or restoring a previously-saved calibration.

Parameters:

`[in]`	asCalUL	ADC counts read at screen upper left corner.
`[in]`	asCalLR	ADC counts read at screen lower right corner.

Returns:: None.

See also:: DspTouchScreen.h

void tcDspTouchScreen::GetCalParams	(	tcDspDisplay::tsScreenCoords &	arCalUL,
		tcDspDisplay::tsScreenCoords &	arCalLR
	)

This routine returns the calibration parameters in use by this instance of tcDspTouchScreen.

This supports saving off a calibration to be restored at a later time.

Parameters:

`[out]`	arCalUL	ADC counts read at screen upper left corner.
`[out]`	arCalLR	ADC counts read at screen lower right corner.

Returns:: None.

See also:: DspTouchScreen.h

bool tcDspTouchScreen::CalUpperLeft ( int anTimeoutMsec )

This is a convenience routine to assist with calibration.

After an application prompts its user to touch the upper left of the screen, this routine may be called to wait for the touch, read the ADC values, and update the current calibration.

Note:: Use tcDspTouchScreen::GetCalParams to retrieve results, if necessary.

Parameters:

[in] anTimeoutMsec How long to wait for a touch (msec).

Returns:: True if successful within the timeout period.

See also:: DspTouchScreen.h

bool tcDspTouchScreen::CalLowerRight ( int anTimeoutMsec )

This is a convenience routine to assist with calibration.

After an application prompts its user to touch the lower right of the screen, this routine may be called to wait for the touch, read the ADC values, and update the current calibration.

Note:: Use tcDspTouchScreen::GetCalParams to retrieve results, if necessary.

Parameters:

[in] anTimeoutMsec How long to wait for a touch (msec).

Returns:: True if successful within the timeout period.

See also:: DspTouchScreen.h

SEM_Handle tcDspTouchScreen::GetTouchSem ( void )

Utility routine to get the active associated semaphore handle used for Touch notifications.

Returns:: Active Semaphore Handle, (may be NULL if none set)

void tcDspTouchScreen::SetTouchSem ( SEM_Handle ahTouchSem )

Utility routine to set the active associated semaphore handle used for Touch notifications.

This routine will override the last set (via the constructor, or this method) semaphore handle for the class.

Parameters:

ahTouchSem

Semaphore Handle to use for notifications (may be NULL)

void tcDspTouchScreen::EnableGPIO ( bool abEnable )

Call this routine to enable continuous polling of the GPIO input data.

Before calling EnableGPIO, you should at make one call to SetOutput() in order to ensure that the output state of the GPIO (if applicable) is in a known condition.

Note:: The GPIO routines are not specific to the ADS7843 touch controller wrapped by this class, but are specific to several Critical Link designed combined LCD / Touchscreen interfaces that provide additional SPI controlled I/O signals. This routine is not required if you are only integrating the touchscreen portion of the controller PCB.

Parameters:

abEnable

When true start polling the I/O from the display SPI controller

bool tcDspTouchScreen::IsGPIOEnabled ( void )

Returns the enabled state from EnableGPIO().

Returns:: true if GPIO polling from the display SPI controller is enabled

void tcDspTouchScreen::SetOutput	(	unsigned int	anMask,
		unsigned int	anValue
	)

Set the output state of the GPIO pins attached to the display SPI controller.

You must call EnableGPIO before the outputs are sent to the controller.

Note:: The GPIO routines are not specific to the ADS7843 touch controller wrapped by this class, but are specific to several Critical Link designed combined LCD / Touchscreen interfaces that provide additional SPI controlled I/O signals. This routine is not required if you are only integrating the touchscreen portion of the controller PCB.

Parameters:

	anMask	a bitmask (24 bits) representing the I/O lines to alter
	anValue	the value for the bits in anMask to change

unsigned int tcDspTouchScreen::GetInputs ( unsigned int anMask )

Gets the most recently polled GPIO Input state from the GPIO devices attached to the display SPI controller.

You must call EnableGPIO before the inputs are read back by the controller.

Note:: The GPIO routines are not specific to the ADS7843 touch controller wrapped by this class, but are specific to several Critical Link designed combined LCD / Touchscreen interfaces that provide additional SPI controlled I/O signals. This routine is not required if you are only integrating the touchscreen portion of the controller PCB.

Parameters:

anMask

a bitmask (24 bits) representing the I/O lines to read

Returns:: the value for the bits in anMask read by the controller

int tcDspTouchScreen::SendDispCommand	(	unsigned int	anCommand,
		SEM_Handle	ahDoneSem
	)

Send an SPI Command to an attached display SPI controller.

Note:: The SendDispCommand and GetDispResponse routines are not specific to the ADS7843 touch controller wrapped by this class, but are specific to several Critical Link designed combined LCD / Touchscreen interfaces that provide additional SPI controlled I/O signals. This routine is not required if you are only integrating the touchscreen portion of the controller PCB.

Parameters:

	anCommand	24 bit command to send to the controller
	ahDoneSem	Semaphore handle (may be NULL) to post when command/response cycle is complete.

Returns:: zero on success, -1 if device is busy

unsigned int tcDspTouchScreen::GetDispResponse ( void )

Retrieve response from an SPI Command issued to an attached display SPI controller.

This is typically called after a SEM_pend() is called on the SEM_Handle ahDoneSem passed into the SendDispCommand method.

Note:: The SendDispCommand and GetDispResponse routines are not specific to the ADS7843 touch controller wrapped by this class, but are specific to several Critical Link designed combined LCD / Touchscreen interfaces that provide additional SPI controlled I/O signals. This routine is not required if you are only integrating the touchscreen portion of the controller PCB.