PIC16F877A-SPI-TC77（溫度傳感器）

#include

#define CS RC2

void initPORT();

void initMSSP();

void delay(unsigned char time);

void display(float data);

float ReadTC77();

const unsigned char disp[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

void main()

{

float temp;

initPORT();

initMSSP();

while(1)

{

temp=ReadTC77();

display(temp);

}

}

/*初始化PIC單片機端口*/

void initPORT()

{

TRISB=0x00; //控制段選

PORTB=0x00;

TRISC=0xf0; //與溫度傳感器連接

PORTC=0x00;

TRISA=0x00; //控制位選

PORTA=0xff;

}

/*初始化MSSP模塊的SPI模式*/

void initMSSP()

{

SSPSTAT=0x00;

SSPCON=0x30;

SSPIF=0;

}

/*讀取溫度傳感器的13位數(shù)值并且轉(zhuǎn)換成浮點類型*/

float ReadTC77()

{

float result,PowerTwo=1;

unsigned char count,HighByte,LowByte;

CS=0;

SSPBUF=0;

while(!SSPIF){}

HighByte=SSPBUF; //獲取溫度寄存器的高字節(jié)

SSPIF=0;

SSPBUF=0;

while(!SSPIF){}

LowByte=SSPBUF; //獲取溫度寄存器的低字節(jié)

SSPIF=0;

CS=1;

for(count=0;count<8;count++) //轉(zhuǎn)換整數(shù)部分

{

PowerTwo*=2;

if(HighByte&(0x01<

}

PowerTwo=1;

for(count=0;count<5;count++) //轉(zhuǎn)換個位及小數(shù)部分

{

if(LowByte&(0x80>>count)) result+=PowerTwo;

PowerTwo=PowerTwo/2.; //注意，不能換成.2，否則會出錯

}

return result; //返回轉(zhuǎn)換浮點結(jié)果

}

/*液晶顯示*/

void display(float data)

{

unsigned int conver,First,Second,Third,Fourth;

conver=data*100;

First=conver/1000;

Second=conver/100%10;

Third=conver/10%10;

Fourth=conver%10;

PORTA=0xfe; //顯示十位

PORTB=disp[First];

delay(2);

PORTB=0x00;

PORTA=0xfd; //顯示個位

PORTB=0x80+disp[Second]; //加上0x80即可帶點

delay(2);

PORTB=0x00;

PORTA=0xfb; //顯示十分位

PORTB=disp[Third];

delay(2);

PORTB=0x00;

PORTA=0xf7; //顯示百分位

PORTB=disp[Fourth];

delay(2);

PORTB=0x00;

}

void delay(unsigned char time)

{

unsigned char i,j;

for(i=time;i>0;i--)

for(j=255;j>0;j--);

}