Header file for XPT2046 touch screen controller driver. More...

#include "main.h"

Data Structures
struct	XPT2046CalibrationValues_t
	Calibration values for XPT2046. More...

struct	XPT2046Coordinates_t
	Coordinates structure for XPT2046. More...

struct	XPT2046Handle_t
	Handle structure for XPT2046. More...

Macros
#define	XPT2046_HOR_RES 240

#define	XPT2046_VER_RES 320

#define	XPT2046_MAX_SAMPLES 100

Enumerations
enum	XPT2046States_t { XPT2046_PRESSED , XPT2046_NOT_PRESSED }
	Touch states for XPT2046. More...

Functions
uint8_t	XPT2046_ReadIRQPin (void)
	Reads the IRQ pin state of the XPT2046.

void	XPT2046_ReadRawData (uint16_t x, uint16_t y)
	Reads raw touch data from the XPT2046.

void	XPT2046_ReadData (XPT2046Handle_t *handle)
	Reads calibrated touch coordinates from the XPT2046.

void	XPT2046_IRQHandler (XPT2046Handle_t *handle)
	Handles touch interrupt for the XPT2046.

void	XPT2046_CallBack (XPT2046Handle_t *handle) __attribute__((weak))
	Callback function for the XPT2046 touch controller.

void	XPT2046_Calibrate (XPT2046Handle_t *handle)
	Calibrates the XPT2046 touch controller.

void	XPT2046_SetCalibrationValues (XPT2046Handle_t handle, XPT2046CalibrationValues_t x_calib, XPT2046CalibrationValues_t *y_calib)
	Sets the calibration values for the XPT2046 touch controller.

void	XPT2046_GetCalibrationValues (XPT2046Handle_t handle, XPT2046CalibrationValues_t x_calib, XPT2046CalibrationValues_t *y_calib)
	Gets the calibration values from the XPT2046 touch controller.

void	XPT2046_Test (XPT2046Handle_t *handle)
	Tests the XPT2046 touch controller.

Detailed Description

Header file for XPT2046 touch screen controller driver.

This file contains the declarations for the XPT2046 touch screen controller driver. It includes function prototypes for reading touch coordinates, handling interrupts, calibrating the touch screen, and performing basic tests. The calibration procedure is implemented based on Texas Instruments' application note SLYT277 "Calibration in touch-screen systems".

See also: https://www.ti.com/lit/an/slyt277/slyt277.pdf for calibration details.

Macro Definition Documentation

◆ XPT2046_HOR_RES

#define XPT2046_HOR_RES 240

Horizontal resolution of the touch screen

◆ XPT2046_MAX_SAMPLES

#define XPT2046_MAX_SAMPLES 100

Maximum number of samples for touch averaging

◆ XPT2046_VER_RES

#define XPT2046_VER_RES 320

Vertical resolution of the touch screen

Enumeration Type Documentation

◆ XPT2046States_t

enum XPT2046States_t

Touch states for XPT2046.

Enumerator
XPT2046_PRESSED	Touch screen is pressed
XPT2046_NOT_PRESSED	Touch screen is not pressed

Function Documentation

◆ XPT2046_Calibrate()

void XPT2046_Calibrate ( XPT2046Handle_t * handle )

Calibrates the XPT2046 touch controller.

Parameters

handle Pointer to the XPT2046 handle structure.

This function performs calibration of the XPT2046 touch controller using three reference points on the screen. The calibration process is based on the method described in the TI application note SLYT277.

Parameters

handle Pointer to the XPT2046 handle structure.

◆ XPT2046_CallBack()

void XPT2046_CallBack ( XPT2046Handle_t * handle )

Callback function for the XPT2046 touch controller.

This is a weak function that can be overridden by the user. It is called when a touch event is processed.

Parameters

handle Pointer to the XPT2046 handle structure.

◆ XPT2046_GetCalibrationValues()

void XPT2046_GetCalibrationValues	(	XPT2046Handle_t *	handle,
		XPT2046CalibrationValues_t *	x_calib,
		XPT2046CalibrationValues_t *	y_calib )

Gets the calibration values from the XPT2046 touch controller.

Parameters

handle	Pointer to the XPT2046 handle structure.
x_calib	Pointer to store the calibration values for the X axis.
y_calib	Pointer to store the calibration values for the Y axis.

This function retrieves the current calibration values from the XPT2046 touch controller.

Parameters

handle	Pointer to the XPT2046 handle structure.
x_calib	Pointer to store the calibration values for the X axis.
y_calib	Pointer to store the calibration values for the Y axis.

◆ XPT2046_IRQHandler()

void XPT2046_IRQHandler ( XPT2046Handle_t * handle )

Handles touch interrupt for the XPT2046.

Parameters

handle Pointer to the XPT2046 handle structure.

This function is the interrupt handler for the XPT2046 touch controller. It reads the touch data and updates the touch state.

Parameters

handle Pointer to the XPT2046 handle structure.

◆ XPT2046_ReadData()

void XPT2046_ReadData ( XPT2046Handle_t * handle )

Reads calibrated touch coordinates from the XPT2046.

Parameters

handle Pointer to the XPT2046 handle structure.

This function reads raw touch data from the XPT2046 and applies calibration coefficients to convert them to screen coordinates.

Parameters

handle Pointer to the XPT2046 handle structure.

◆ XPT2046_ReadIRQPin()

uint8_t XPT2046_ReadIRQPin ( void )

Reads the IRQ pin state of the XPT2046.

Return values

uint8_t 1 if the pin is high, 0 if the pin is low.

This function reads the state of the IRQ pin of the XPT2046 touch controller.

Return values

uint8_t 1 if the pin is high, 0 if the pin is low.

◆ XPT2046_ReadRawData()

void XPT2046_ReadRawData	(	uint16_t *	x,
		uint16_t *	y )

Reads raw touch data from the XPT2046.

Parameters

x	Pointer to store the raw x-coordinate.
y	Pointer to store the raw y-coordinate.

This function reads the raw touch data from the XPT2046 touch controller by sending appropriate commands via SPI and processing the received data. It implements a simple averaging filter to improve the touch data quality.

Parameters

x	Pointer to store the raw x-coordinate.
y	Pointer to store the raw y-coordinate.

◆ XPT2046_SetCalibrationValues()

void XPT2046_SetCalibrationValues	(	XPT2046Handle_t *	handle,
		XPT2046CalibrationValues_t *	x_calib,
		XPT2046CalibrationValues_t *	y_calib )

Sets the calibration values for the XPT2046 touch controller.

Parameters

handle	Pointer to the XPT2046 handle structure.
x_calib	Pointer to the calibration values for the X axis.
y_calib	Pointer to the calibration values for the Y axis.

This function updates the calibration values for the XPT2046 touch controller.

Parameters

handle	Pointer to the XPT2046 handle structure.
x_calib	Pointer to the calibration values for the X axis.
y_calib	Pointer to the calibration values for the Y axis.

◆ XPT2046_Test()

void XPT2046_Test ( XPT2046Handle_t * handle )

Tests the XPT2046 touch controller.

Parameters

handle Pointer to the XPT2046 handle structure.

This function tests the XPT2046 touch controller by reading the touch coordinates and drawing a target on the screen at the touch location.

Parameters

handle Pointer to the XPT2046 handle structure.

Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ XPT2046_HOR_RES

◆ XPT2046_MAX_SAMPLES

◆ XPT2046_VER_RES

Enumeration Type Documentation

◆ XPT2046States_t

Function Documentation

◆ XPT2046_Calibrate()

◆ XPT2046_CallBack()

◆ XPT2046_GetCalibrationValues()

◆ XPT2046_IRQHandler()

◆ XPT2046_ReadData()

◆ XPT2046_ReadIRQPin()

◆ XPT2046_ReadRawData()

◆ XPT2046_SetCalibrationValues()

◆ XPT2046_Test()