驱动XPT2046一个很奇怪的现象，大家看下怎么回事

张衍波 · 发表于 2015-10-8 07:18:10

程序的功能是采集触摸屏坐标，然后在此坐标画点。但是却出现下图的现象，换了两套滤波消抖算法，甚至换了另一个方案的屏还是这样。纠结两天了，大家帮忙看下是怎么回事。

经过验证，绘图算法是没有问题的。而且根据LOG发现，问题根源应该是在触摸驱动上。但是小弟真的琢磨不出是什么原因。

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "xpt2046.h"
#include "lcd.h"
#include "pin.h"

#define TP_CS_LOW() {PBout(12) = 0;}
#define TP_CS_HIGH() {PBout(12) = 1;}

#define ADJUST_TOUCH_DELAY 500

#define FILTER_SAMPLE 9

#define ADJUST_POINT1 LCD_WIDTH*1/6,LCD_HEIGHT*1/6
#define ADJUST_POINT2 LCD_WIDTH*5/6,LCD_HEIGHT*1/6
#define ADJUST_POINT3 LCD_WIDTH*1/6,LCD_HEIGHT*5/6
#define ADJUST_POINT4 LCD_WIDTH*5/6,LCD_HEIGHT*5/6
#define ADJUST_POINT5 LCD_WIDTH/2,LCD_HEIGHT/2

extern SPI_HandleTypeDef hspi2;

//X: 0.014766,-0.001094,-39.920000
//Y: -0.021198,-0.000286,618.693333

//double Ax = 0.012000,Bx = -0.001094, Cx = -39.920000;
//double Ay = -0.021198,By = -0.000286,Cy = 618.693333;

double Ax = 0.015193,Bx = 0.000179,Cx = -93.940186;
double Ay = -0.020224,By = -0.000281,Cy = 591.518222;

//double Ax,Bx,Cx;
//double Ay,By,Cy;

BOOL adjust_enable = FALSE;
BOOL adjust_pressed = FALSE;

void _sort(uint16_t dat[])
{

      uint16_t tmp;
      for(int i = 0 ; i < FILTER_SAMPLE - 1 ; i ++)
      {
            for(int j = 1 ; j < FILTER_SAMPLE; j ++)
            {
                     if(dat[i] > dat[j])
                     {
                              tmp = dat[i];
                              dat[i] = dat[j];
                              dat[j] = tmp;
                     }
            }
      }
}

/*
* Read raw ad value.
*/
void XPT2046_GetRawPos_(uint16_t *x, uint16_t *y)
{
      uint8_t tx_buf, rx_buf;
      TP_CS_LOW();

      tx_buf = 0xD0;
      HAL_SPI_TransmitReceive(&hspi2, &tx_buf, &rx_buf, 1, 2000);

      tx_buf = 0x00;
      HAL_SPI_TransmitReceive(&hspi2, &tx_buf, &rx_buf, 1, 2000);
      *x = rx_buf << 8;

      tx_buf = 0x00;
      HAL_SPI_TransmitReceive(&hspi2, &tx_buf, &rx_buf, 1, 2000);
      *x += rx_buf;

      tx_buf = 0x90;
      HAL_SPI_TransmitReceive(&hspi2, &tx_buf, &rx_buf, 1, 2000);

      tx_buf = 0x00;
      HAL_SPI_TransmitReceive(&hspi2, &tx_buf, &rx_buf, 1, 2000);
      *y = rx_buf << 8;

      tx_buf = 0x00;
      HAL_SPI_TransmitReceive(&hspi2, &tx_buf, &rx_buf, 1, 2000);
      *y += rx_buf;

      TP_CS_HIGH();

      *y >>=2;
      *x >>=2;
}

static void _delay()
{
      for(int i = 10000; i --;);
}

/*
*       AD Fliter
*/
void XPT2046_GetRawPos(uint16_t *x, uint16_t *y)
{
      uint16_t rx[FILTER_SAMPLE], ry[FILTER_SAMPLE];
      float jx[FILTER_SAMPLE/3],jy[FILTER_SAMPLE/3];
      int m0,m1,m2;
      int tmx,tmy;

      RESTART:

      for(int i = 0 ; i < FILTER_SAMPLE ; i ++)
      {
            XPT2046_GetRawPos_(&rx[i],&ry[i]);
            printf("=%hd,%hd=",rx[i],ry[i]);
            HAL_Delay(1);
      }

      jx[0] = (rx[0] + rx[1] + rx[2])/3;
      jx[1] = (rx[3] + rx[4] + rx[5])/3;
      jx[2] = (rx[6] + rx[7] + rx[8])/3;
      m0 = jx[0] - jx[1];
      m1 = jx[1] - jx[2];
      m2 = jx[2] - jx[0];
      m0=m0>0? m0

-m0);
m1=m1>0? m1

-m1);
m2=m2>0? m2

-m2);

      //printf("%d,%d,%d\r\n",m0,m1,m2);

      if(m0 > 200 && m1 > 200 && m2 > 200)
            goto RESTART;

      if(m0<m1) {
            if(m2<m0)
                     tmx=(jx[0]+jx[2])/2;
            else
                     tmx=(jx[0]+jx[1])/2;
      }else {
            if(m2<m1)
                     tmx=(jx[0]+jx[2])/2;
            else
                     tmx=(jx[1]+jx[2])/2;
      }

      jy[0] = (ry[0] + ry[1] + ry[2])/3;
      jy[1] = (ry[3] + ry[4] + ry[5])/3;
      jy[2] = (ry[6] + ry[7] + ry[8])/3;
      m0 = jy[0] - jy[1];
      m1 = jy[1] - jy[2];
      m2 = jy[2] - jy[0];
      m0=m0>0? m0

-m0);
m1=m1>0? m1

-m1);
m2=m2>0? m2

-m2);

      if(m0 > 200 && m1 > 200 && m2 > 200)
            goto RESTART;

      if(m0<m1) {
            if(m2<m0)
                     tmy=(jy[0]+jy[2])/2;
            else
                     tmy=(jy[0]+jy[1])/2;
      }else {
            if(m2<m1)
                     tmy=(jy[0]+jy[2])/2;
            else
                     tmy=(jy[1]+jy[2])/2;
      }

      *x = tmx;
      *y = tmy;
}

void Touch_GetPosition(uint16_t *x, uint16_t *y)
{
      uint16_t rx,ry;
      XPT2046_GetRawPos(&rx, &ry);

      *x = Ax * rx + Bx * ry + Cx;
      *y = Ay * ry + By * rx + Cy;

      printf("--%hd,%hd,%hd,%hd \r\n",*x,*y,rx,ry);
}

static void _draw_cross(uint16_t x, uint16_t y)
{
      x -= 10;
      for(uint16_t i = 0; i < 20; i++)
      {
            Lcd_DrawPixel(x + i, y,Red);
      }
      x += 10;
      y -= 10;
      for(uint16_t i = 0; i < 20; i++)
      {
            Lcd_DrawPixel(x, y + i,Red);
      }
}

static void calculate(int X1, int Y1, int C1,
                        int X2, int Y2, int C2,
                        int X3, int Y3, int C3,
                        double *A ,double *B ,double *C)
{
      double a = X1;
      double b = Y1;
      double c = 1;
      double d = C1;

      double e = X2;
      double f = Y2;
      double g = 1;
      double h = C2;

      double i = X3;
      double j = Y3;
      double k = 1;
      double l = C3;

      //
      double delta = (a*f*k)+(b*g*i)+(c*e*j)-(c*f*i)-(a*g*j)-(b*e*k);

      //
      double xnum = (d*f*k)+(b*g*l)+(c*h*j)-(c*f*l)-(d*g*j)-(b*h*k);
      double xans = xnum/delta;
      *A = xans;

      //
      double ynum = (a*h*k)+(d*g*i)+(c*e*l)-(c*h*i)-(a*g*l)-(d*e*k);
      double yans = ynum/delta;
      *B = yans;

      //
      double znum = (a*f*l)+(b*h*i)+(d*e*j)-(d*f*i)-(a*h*j)-(b*e*l);
      double zans = znum/delta;
      *C = zans;
}

BOOL ADJUST_TOUCH_IRQ(void)
{
      adjust_pressed = TRUE;
      return adjust_enable;
}

void Touch_Adjust(void)
{
      uint16_t x1,x2,x3,x4,x5;
      uint16_t y1,y2,y3,y4,y5;
      adjust_enable = TRUE;

      Lcd_Clear(White);
      _draw_cross(ADJUST_POINT1);
      while(adjust_pressed != TRUE){}
      XPT2046_GetRawPos(&x1,&y1);
      HAL_Delay(ADJUST_TOUCH_DELAY);
      adjust_pressed = FALSE;

      Lcd_Clear(White);
      _draw_cross(ADJUST_POINT2);
      while(adjust_pressed != TRUE){}
      XPT2046_GetRawPos(&x2,&y2);
      HAL_Delay(ADJUST_TOUCH_DELAY);
      adjust_pressed = FALSE;

      Lcd_Clear(White);
      _draw_cross(ADJUST_POINT3);
      while(adjust_pressed != TRUE){}
      XPT2046_GetRawPos(&x3,&y3);
      HAL_Delay(ADJUST_TOUCH_DELAY);
      adjust_pressed = FALSE;

      Lcd_Clear(White);
      _draw_cross(ADJUST_POINT4);
      while(adjust_pressed != TRUE){}
      XPT2046_GetRawPos(&x4,&y4);
      HAL_Delay(ADJUST_TOUCH_DELAY);
      adjust_pressed = FALSE;

      Lcd_Clear(White);
      _draw_cross(ADJUST_POINT5);
      while(adjust_pressed != TRUE){}
      XPT2046_GetRawPos(&x5,&y5);
      HAL_Delay(ADJUST_TOUCH_DELAY);
      adjust_pressed = FALSE;

      printf("%hx,%hx,%hx,%hx,%hx,\r\n",x1,x2,x3,x4,x5);
      printf("%hx,%hx,%hx,%hx,%hx,\r\n",y1,y2,y3,y4,y5);

      calculate(x1,y1,LCD_WIDTH*1/6,
                                             x2,y2,LCD_WIDTH*5/6,
                                             x4,y4,LCD_WIDTH*5/6,
                                             &Ax,&Bx,&Cx);

      calculate(y1,x1,LCD_HEIGHT*1/6,
                                             y2,x2,LCD_HEIGHT*1/6,
                                             y4,x4,LCD_HEIGHT*5/6,
                                             &Ay,&By,&Cy);

      printf("X: %f,%f,%f\r\n",Ax,Bx,Cx);
      printf("Y: %f,%f,%f\r\n",Ay,By,Cy);

      Lcd_Clear(White);
      adjust_enable = FALSE;
}
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