ATMEGA16用IO模擬SPI驅(qū)動ADS7843

最近在搞AVR單片機(jī)的ILI9325的驅(qū)動、簡單GUI的移植，成功之后就搞ADS7843的驅(qū)動，用avr-gcc (WinAVR 20100110) 4.3.3編譯。

其效果如下圖：

以下是其驅(qū)動程序：

typedef unsigned char BYTE; // 8-bit

typedef unsigned int WORD; // 16-bit

typedef unsigned long DWORD; // 32-bit

#define _nop_() asm("NOP")

#define touch_PORT PORTB

#define PEN_Q 7

#define DOUT 6

#define DIN 5 //引腳定義

#define CS 4 //mega16

#define DCLK 3

#define SPI_CS_Assert() touch_PORT &= ~_BV(CS)

#define SPI_CS_Deassert() touch_PORT |= _BV(CS)

WORD TP_X=1,TP_Y=1; //當(dāng)前觸控坐標(biāo)

//**********************************************************

void SPI_Init(void) //SPI開始

{

DDRB|=_BV(CS)|_BV(DCLK)|_BV(DIN);

touch_PORT|=_BV(CS)|_BV(DCLK)|_BV(DIN);

}

//**********************************************************

void WriteCharTo7843(unsigned char num) //SPI寫數(shù)據(jù)

{

unsigned char count=0,temp;

touch_PORT&=~_BV(DCLK);

for(count=0;count<8;count++)

{

temp=num;

if(temp&0x80)

touch_PORT|=_BV(DIN);

else

touch_PORT&=~_BV(DIN);

num<<=1;

touch_PORT&=~_BV(DCLK);

_nop_();_nop_();_nop_(); //上升沿有效

touch_PORT|=_BV(DCLK);

_nop_();_nop_();_nop_();

}

}

//**********************************************************

unsigned int ReadFromCharFrom7843(void) //SPI 讀數(shù)據(jù)

{

unsigned char count=0;

unsigned int Num=0;

for(count=0;count<12;count++)

{

Num<<=1;

touch_PORT|=_BV(DCLK);

_nop_();_nop_();_nop_(); //下降沿有效

touch_PORT&=~_BV(DCLK);

_nop_();_nop_();_nop_();

if(PINB&_BV(DOUT))

Num++;

}

return(Num);

}

void AD7843(void) //接收11次后求10次的平均值

{

static WORD X_TEMP[11],Y_TEMP[11];

static BYTE count=0;

WORD lx=0,ly=0;

if (!(PINB&_BV(PEN_Q)))

{

_delay_us(500);

while (!(PINB&_BV(PEN_Q)))

{

SPI_CS_Assert();

WriteCharTo7843(0x90); //送控制字 10010000 即用差分方式讀X坐標(biāo) 詳細(xì)請見有關(guān)資料

touch_PORT|=_BV(DCLK);

_nop_();_nop_();_nop_();

touch_PORT&=~_BV(DCLK);

_nop_();_nop_();_nop_();

Y_TEMP[count]=ReadFromCharFrom7843();

WriteCharTo7843(0xD0); //送控制字 11010000 即用差分方式讀Y坐標(biāo) 詳細(xì)請見有關(guān)資料

touch_PORT|=_BV(DCLK);

_nop_();_nop_();_nop_();

touch_PORT&=~_BV(DCLK);

_nop_();_nop_();_nop_();

X_TEMP[count]=ReadFromCharFrom7843();

SPI_CS_Deassert();

if(count++==10)

{

for(count=0;count<10;count++)

{

X_TEMP[10]+=X_TEMP[count];

Y_TEMP[10]+=Y_TEMP[count];

}

TP_X=X_TEMP[10]/10;

TP_Y=Y_TEMP[10]/10;

count=0;

// GUI_wrul(100,20,TP_X,RGB(120,255,0),color[2]);//(uchar x, uint y, unsigned long num, uint color,uint b_color);

// GUI_wrul(200,20,TP_Y,RGB(120,255,0),color[2]);

lx=240-((TP_X-240)/16); //將AD值轉(zhuǎn)換位顯示屏坐標(biāo)

ly=320-((TP_Y-380)/12); //將AD值轉(zhuǎn)換位顯示屏坐標(biāo)

// GUI_wrul(100,40,X_TEMP[10],RGB(120,255,0),color[2]);//(uchar x, uint y, unsigned long num, uint color,uint b_color);

// GUI_wrul(200,40,Y_TEMP[10],RGB(120,255,0),color[2]);

GUI_Point(lx,ly,RGB(250,0,250));

Y_TEMP[10]=0;

X_TEMP[10]=0;

}

}

count=0;

}

}

整個程序比較簡單，自己分析吧。