ARM板开发触摸屏程序，出现飘屏！急求解决办法！
我用ARM板测试一个触摸屏程序，偶尔出现飘屏！
源码如下：
- C/C++ code
#include "def1.h"#include "2440addr.h"#include "2440lib.h"#include "config.h"#define REQCNT 30#define ADCPRS 9 //YH 0627#define LOOP 1void AdcTsAuto(void);int TouchPanelCnt=0; // 触摸屏次数的记录struct TouchLocation{ volatile int x; volatile int y;}TPxyLocation = {0,0};volatile int test_x; volatile int test_y; INT8U ts_status;//触摸屏的状态（校准还是测试）//static U16 ts_lefttop_x,ts_lefttop_y,ts_rightbot_x,ts_rightbot_y,ts_leftbot_x, //ts_leftbot_y,ts_righttop_x,ts_righttop_y; struct TouchLocation TestPoint[8] = {0};extern void AdcTsAuto_Handler(void);extern OS_EVENT *TP_m_box;//extern OS_EVENT *Cal_m_box; //extern OS_EVENT *Lag_m_box; //unsigned int buf[3][2];U16 Ptx[6],Pty[6],tmp[6] = {0,0,0,0,0,0};//U8 index = 0;void AdcTsAuto(void){ int i; U32 saveAdcdly; if(rADCDAT0&0x8000) { //Uart_Printf("\nStylus Up!!\n"); rADCTSC&=0xff; // Set stylus down interrupt bit } //else // Uart_Printf("\nStylus Down!!\n"); rADCTSC=(1<<3)|(1<<2); //Pull-up disable, Seq. X,Y postion measure. saveAdcdly=rADCDLY; rADCDLY=40000; //Normal conversion mode delay about (1/50M)*40000=0.8ms rADCCON|=0x1; //start ADC for(i=0;i<5;i++) { // rADCTSC = (1<<7)|(1<<6)|(0<<5)|(1<<4)|(1<<3)|(1<<2)|(0); rADCTSC=(1<<3)|(1<<2); //Pull-up disable, Seq. X,Y postion measure. saveAdcdly=rADCDLY; rADCDLY=40000; //Normal conversion mode delay about (1/50M)*40000=0.8ms rADCCON |= 0x1; //Start Auto conversion while(rADCCON & 0x1); //Check if Enable_start is low while(!(0x8000&rADCCON)); //Check ECFLG while(!(rSRCPND & (BIT_ADC))); //check if ADC is finished with interrupt bit Pty[i] = (0x3ff&rADCDAT1); Ptx[i] = (0x3ff&rADCDAT0); //OSPrintf("----- ========(%04d,%04d)=======\n",Ptx[i], Pty[i]); } // buf[3][0] =((buf[0][0] + buf[1][0] + buf[2][0])/3)*10; //buf[3][1] =((buf[0][1] + buf[1][1] + buf[2][1])/3)*10; Ptx[5]=(Ptx[0]+Ptx[1]+Ptx[2]+Ptx[3]+Ptx[4])/5; Pty[5]=(Pty[0]+Pty[1]+Pty[2]+Pty[3]+Pty[4])/5; OSPrintf(" ========(%04d,%04d)=======\n",Ptx[5], Pty[5]); //OSPrintf("----- ========(%04d,%04d)=======\n",TPxyLocation.x,TPxyLocation.y); TPxyLocation.x=Ptx[5]*10; TPxyLocation.y=Pty[5]*10; //TPxyLocation.x=TPxyLocation.x*10; // TPxyLocation.y=TPxyLocation.y*10; //OSMboxPost(TP_m_box,(void*)1); //YH 0627, To check Stylus Up Interrupt. rSUBSRCPND|=BIT_SUB_TC; ClearPending(BIT_ADC); rINTSUBMSK&=~(BIT_SUB_TC); rINTMSK&=~(BIT_ADC); rADCTSC =0xd3; //Waiting for interrupt rADCTSC=rADCTSC|(1<<8); // Detect stylus up interrupt signal. while(1) //to check Pen-up state { if(rSUBSRCPND & (BIT_SUB_TC)) //check if ADC is finished with interrupt bit { //Uart_Printf("Stylus Up Interrupt~!\n"); break; //if Stylus is up(1) state } } //Uart_Printf("count=%03d XP=%04d, YP=%04d\n", TouchPanelCnt++, TPxyLocation.x, TPxyLocation.y); //X-position Conversion data OSMboxPost(TP_m_box,(void*)1); rADCDLY=saveAdcdly; rADCTSC=rADCTSC&~(1<<8); // Detect stylus Down interrupt signal. rSUBSRCPND|=BIT_SUB_TC; rINTSUBMSK &=~(BIT_SUB_TC); // Unmask sub interrupt (TC) ClearPending(BIT_ADC);}void Test_Touchpanel(void){ //OSPrintf("ADC touch screen test\n"); //OSPrintf("[1] calibration touch screen \n"); // OSPrintf("Please touch the location of left top \n"); //ts_status = TS_JUSTIFY_LEFTTOP; rADCDLY=50000; //Normal conversion mode delay about (1/3.6864M)*50000=13.56ms rADCCON=(1<<14) | (ADCPRS<<6);//| (0<<3) | (0<<2) | (0<<1) | (0); //ADCPRS En, ADCPRS Value rADCTSC=0xd3; //Wfait,XP_PU,XP_Dis,XM_Dis,YP_Dis,YM_En // pISR_ADC = (uint32)AdcTsAuto_Handler; pISR_ADC = (int)AdcTsAuto; rINTMSK &= ~BIT_ADC; //ADC Touch Screen Mask bit clear rINTSUBMSK &= ~(BIT_SUB_TC);}
谁能帮我看看这段代码有问题麽！
[解决办法]
仅仅是多次采样求平均还是不够的，
在求平均之前最好先去除一个最大值和一个最小值，
特别是在轻按时这个差值会很大，从而导致楼主所说的问题。
[解决办法]
每次采样时，需要与前几次的平均值比较，差别很大的叫“野点”，应该去除。这个叫滤波；当前后两次的差值小于某个值时，这个值也不能要，这个叫去抖动。
一般来说，触摸屏 应该做 去抖动 和 滤波。
一般来说， 去抖动 和 滤波需要在驱动层做。但如果你是用linux的话，请搜索下libts，它已经在应用层帮你做得很好了。
[解决办法]
最好先检查一下硬件,看ADC的参考电压是否稳,还是说参考电压上面有毛刺出现.
[解决办法]
你说的漂屏，不知有多严重，如果是开发板，用别人的程序看一下，有没有这个问题，一般都是硬件问题造成的，也就是AD采样不稳定。软件能做的，也就是数字滤波，比如采8次，回来放到一个数据，去掉最大值，去掉最小值，然后求平均值，三星官方BSP里面的TOUCH驱动，也都是这样做的。