ADS7843/XPT2046 touch screen chip 8051 MCU driver

The size of my color screen is 240*320~

Following is the code

//common.h

#ifndef __COMMON_H__

#define __COMMON_H__

#include

#include

typedef unsigned int uint;

typedef unsigned char uchar;

#endif // !__COMMON_H__

//TouchPad.c

#define __TOUCHPAD_C__

#include "TouchPad.h"

//My screen interface

//#include "gdi.h"

sbit TP_CLK = P1^4; //clock

sbit TP_CS = P1^5; //Chip select

sbit TP_IN = P1^6; //Data input

//sbit TP_BUSY = P1^3; //I don't use the busy flag

sbit TP_OUT = P1^7; //data output

sbit TP_IRQ = P3^2; //Notify MCU via INT0

/*

 * Function: Check whether the touch screen is in interruption and call the detection function in the interruption

 * Parameters: (none)

 * Return: 0-No, non-0: the touch screen is pressed

 */

uchar tp_isirq(void)

{

    return !(uchar)TP_IRQ;

}

// Enable external interrupt 1 and notify MCU through external interrupt

void tp_init(void)

{

    EX0 = 1;

    IT0 = 1;

    EA = 1;

    TP_CS = 1;

    TP_CLK = 1;

    TP_IN = 1;

    TP_CLK = 1;

}

/* Function: write a byte in SPI mode

 * Parameters: ch: uchar: byte value

 * Returns: (None)

 */

void tp_write(uchar ch)

{

    uchar k;

    TP_CLK = 0;

    for(k=0; k<8; k++){

        ch <<= 1;

        TP_IN = CY;

        TP_CLK = 0;

        _nop_();

        TP_CLK = 1;

        _nop_();

    }

}

/*

 * Function: SPI mode read function

 * Parameters: (none)

 * Return value: 12 bits of valid data

 */

uint tp_read(void)

{

    uchar k;

    uint ret = 0;

    for(k=0; k<12; k++){

        ret <<= 1;

        TP_CLK = 1;

        _nop_();

        TP_CLK = 0;

        _nop_();

        if(TP_OUT)

            ret++;

    }

    return ret;

}

/*

 * Function: Get X, Y coordinates, but no comparison sampling

 * Parameter: struct tp_point structure pointer

 * Returns: (None)

 * Note: Do not call externally, there will be errors

 */

void tp_get_pt(struct tp_point* pt)

{

    TP_CS = 0;

    tp_write(0x90); //Read Y

    TP_CLK = 1;

    _nop_();

    TP_CLK = 0;

    _nop_();

    pt->y = tp_read();

    tp_write(0xd0); //Read X

    TP_CLK = 1;

    _nop_();

    TP_CLK = 0;

    _nop_();

    pt->x = tp_read();

    TP_CS = 1;

}

/*

 * Function: Get the touch screen coordinate function

 * Parameter: int type x, y pointer

 * return value:

 * Return 0 - sampling failed

 * Returns non-zero valid samples

*/

int tp_get(int* px, int* py)

{

    struct tp_point pt1;

    struct tp_point pt2;

    int x,y;

    //Twice the value and sample

    tp_get_pt(&pt1);

    tp_get_pt(&pt2);

    x = pt1.x-pt2.x;

    y = pt1.y-pt2.y;

    //The error is not too big, then it is valid

    if(x<2 && y<2)

    {

        //This calculation is not clear yet.

        *px = 240-(pt1.x-330)*10/142;

        *py = 320-(pt1.y-380)/11;

        return 1;

    }

    return 0;

}

//TouchPad.h

/*

    File:TouchPad.h

    Description: Touch screen related support files

    Text:ts=4, sw=4, sts=4

*/

#ifndef __TOUCHPAD_H__

#define __TOUCHPAD_H__

#include "common.h"

//common.h

/*

typedef unsigned char uchar;

typedef unsigned int uint;

#include

*/

int tp_get(int* px, int* py); //Get the current coordinate point, the return value is not zero if it is valid

void tp_init(void); //touch screen initialization function

uchar tp_isirq(void); //Judge whether the touch screen is still in interruption

#ifdef __TOUCHPAD_C__

//Internal structure, function

struct tp_point{

    int x;

    int y;

};

void tp_get_pt(struct tp_point* pt);

uint tp_read(void);

void tp_write(uchar ch);

#undef __TOUCHPAD_C__

#endif

#endif // !__TOUCHPAD_H__

//Example usage

//main.c

#include "common.h"

#include "TouchPad.h"

//The touch screen notifies the MCU to sample via external interrupt 0

//Should be written in the main module

void int0(void) interrupt 0

{

    int x=0,y=0;

    EA = 0;

    while(1){

        if(tp_isirq()){

            if(!tp_get(&x, &y))     

                continue;   

            //x,y are the coordinates obtained

            //set_pixel is my screen drawing function

            //Change to your own usage method

            //set_pixel(x,y, 0xaaaa);

            //set_pixel(x+1,y, 0xaaaa);

            //set_pixel(x,y+1, 0xaaaa);

            //set_pixel(x+1,y+1, 0xaaaa);

        }else{

            break;

        }

    }

    EA = 1;

}

void main(void)

{

    //delay_ms(200);//self-implementation

    tp_init();

    while(1)

        ;

}