rtouch.c File Reference

Resistive Touch Service.

Copyright (c) 2011-2018 Microchip Technology Inc. and its subsidiaries.

#include "board.h"
#include "ioport.h"
#include "rtouch.h"

Macros
#define	DEBOUNCE_TIME   6 /* 10 * 6 = 60 ms */
	Delay for pushbutton debouncing (the time-base is 10 ms). More...
#define	MULTI_FACTOR   1024
	The multiplicator value used by the calibration algorithm to avoid working on float values. More...
#define	POINTS_MAX_ERROR   5
	Maximum difference in pixels between the test point and the measured point. More...

Typedefs
typedef enum rtouch_pen_state_enum	rtouch_pen_state_t
	Pen state definitions. More...

Enumerations
enum	rtouch_pen_state_enum {   STATE_PEN_RELEASED = 0,   STATE_PEN_PRESSED = 1,   STATE_PEN_DEBOUNCE = 2 }
	Pen state definitions. More...

Functions
uint32_t	rtouch_compute_calibration (rtouch_calibration_point_t *points)
	Perform the calibration process using the provided points. More...
void	rtouch_disable (void)
	Disable the resistive touch service. More...
static void	rtouch_disable_pen_interrupt (void)
	Disable PEN interrupts. More...
void	rtouch_enable (void)
	Enable the resistive touch service for touch detection and sampling. More...
static void	rtouch_enable_pen_interrupt (void)
	Enable PEN interrupts. More...
static void	rtouch_get_calibrated_point (const rtouch_point_t *p_raw, rtouch_point_t *p_point)
	Interpolate the provided raw measurements using the previously calculated slope. More...
rtouch_event_handler_t	rtouch_get_event_handler (void)
	Get the touch event handler. More...
uint32_t	rtouch_init (const uint32_t ul_width, const uint32_t ul_height)
	Initialize the resistive touch service. More...
static uint8_t	rtouch_is_calibrated (void)
	Indicates if the calibration of the touch screen is Ok. More...
static void	rtouch_pen_handler (void)
	Handler for PEN interrupts. More...
void	rtouch_process (void)
	Core function for resistive touch service. More...
void	rtouch_set_calibration_parameter (int32_t xslope, int32_t yslope, int32_t rawx, int32_t rawy)
	Set calibration parameters when manual calibration procedure is not performed. More...
void	rtouch_set_event_handler (rtouch_event_handler_t handler)
	Set the touch event handler. More...
void	rtouch_wait_pressed (void)
	Wait touch pressed. More...
void	rtouch_wait_released (void)
	Wait touch released. More...

Variables
static rtouch_calibration_point_t	calibration_point_0
	First calibration point (required for processing point). More...
static rtouch_event_t	event
	Current touch screen event. More...
static rtouch_event_handler_t	event_handler
	User event handler function pointer. More...
static int32_t	g_l_xslope
	Slope for interpoling touchscreen measurements along the X-axis. More...
static int32_t	g_l_yslope
	Slope for interpoling touchscreen measurements along the Y-axis. More...
static uint32_t	g_ul_height
static volatile uint32_t	g_ul_is_calibrated = 0
	indicates if the touch screen has been calibrated. More...
static volatile uint32_t	g_ul_is_rtouch_enabled = 0
	Touch screen enable flag. More...
static volatile uint32_t	g_ul_timepress = 0
	last time when the pen is pressed on the touchscreen. More...
static volatile uint32_t	g_ul_timerelease = 0
	last time when the pen is released. More...
static volatile uint32_t	g_ul_timestamp = 0
	Global g_ul_timestamp in milliseconds since start of application. More...
static uint32_t	g_ul_width
	Panel size. More...
static volatile rtouch_pen_state_t	pen_state = STATE_PEN_RELEASED
	Pen current state. More...

#define DEBOUNCE_TIME   6 /* 10 * 6 = 60 ms */

Delay for pushbutton debouncing (the time-base is 10 ms).

Referenced by rtouch_process().

#define MULTI_FACTOR   1024

The multiplicator value used by the calibration algorithm to avoid working on float values.

Referenced by rtouch_compute_calibration(), and rtouch_get_calibrated_point().

#define POINTS_MAX_ERROR   5

Maximum difference in pixels between the test point and the measured point.

Referenced by rtouch_compute_calibration(), and rtouch_process().

typedef enum rtouch_pen_state_enum rtouch_pen_state_t

Pen state definitions.

enum rtouch_pen_state_enum

Pen state definitions.

Enumerator
STATE_PEN_RELEASED
STATE_PEN_PRESSED
STATE_PEN_DEBOUNCE

static void rtouch_disable_pen_interrupt ( void  )

static

Disable PEN interrupts.

Disable the interrupt

References rtouch_disable_interrupt.

Referenced by rtouch_disable().

static void rtouch_enable_pen_interrupt ( void  )

static

Enable PEN interrupts.

Initialize interrupts

Enable the interrupt

References rtouch_enable_interrupt, rtouch_pen_handler(), and rtouch_set_handler.

Referenced by rtouch_enable().

static void rtouch_get_calibrated_point ( const rtouch_point_t *  p_raw, rtouch_point_t *  p_point  )

static

Interpolate the provided raw measurements using the previously calculated slope.

The resulting x and y coordinates are stored in an array.

Parameters

p_data	Raw measurement data.
p_point	Array in which x and y will be stored.

References g_l_xslope, g_l_yslope, g_ul_height, g_ul_width, MULTI_FACTOR, rtouch_calibration_point_struct::panel, rtouch_calibration_point_struct::raw, rtouch_point_struct::x, and rtouch_point_struct::y.

Referenced by rtouch_compute_calibration(), and rtouch_process().

static uint8_t rtouch_is_calibrated ( void  )

static

Indicates if the calibration of the touch screen is Ok.

Returns

1 calibration Ok, 0 if not.

References g_ul_is_calibrated.

Referenced by rtouch_process().

static void rtouch_pen_handler ( void  )

static

Handler for PEN interrupts.

Check if the touch screen has been pressed

References g_ul_timestamp, rtouch_is_pressed, STATE_PEN_DEBOUNCE, STATE_PEN_PRESSED, and STATE_PEN_RELEASED.

Referenced by rtouch_enable_pen_interrupt().

rtouch_calibration_point_t calibration_point_0

static

First calibration point (required for processing point).

rtouch_event_t event

static

Current touch screen event.

rtouch_event_handler_t event_handler

static

User event handler function pointer.

Referenced by rtouch_get_event_handler(), and rtouch_process().

int32_t g_l_xslope

static

Slope for interpoling touchscreen measurements along the X-axis.

Referenced by rtouch_get_calibrated_point().

int32_t g_l_yslope

static

Slope for interpoling touchscreen measurements along the Y-axis.

Referenced by rtouch_get_calibrated_point().

uint32_t g_ul_height

static

Referenced by rtouch_get_calibrated_point().

volatile uint32_t g_ul_is_calibrated = 0

static

indicates if the touch screen has been calibrated.

If not, Callback functions are not called.

Referenced by rtouch_is_calibrated().

volatile uint32_t g_ul_is_rtouch_enabled = 0

static

Touch screen enable flag.

volatile uint32_t g_ul_timepress = 0

static

last time when the pen is pressed on the touchscreen.

Referenced by rtouch_process().

volatile uint32_t g_ul_timerelease = 0

static

last time when the pen is released.

Referenced by rtouch_process().

volatile uint32_t g_ul_timestamp = 0

static

Global g_ul_timestamp in milliseconds since start of application.

Referenced by rtouch_pen_handler(), and rtouch_process().

uint32_t g_ul_width

static

Panel size.

Referenced by rtouch_get_calibrated_point().

volatile rtouch_pen_state_t pen_state = STATE_PEN_RELEASED

static

Pen current state.