SD18b20溫度在液晶屏

/*程序功能：在1602液晶屏上顯示當(dāng)前溫度涉及芯片：1602液晶、SD18b20溫度傳感器*///*****************************************************************#include#define uint unsigned int #define uchar unsigned charsbit DQ=P0^3;sbit rs=P2^0;sbit rw=P2^1;sbit en=P2^2;uchar low,high;//====================================函數(shù)聲明//*********sd18b20*******************void delayus(uint time);void init_18b20();void write_18b20(uchar date);uchar read_18b20();void wndu();//**********1602液晶**************void init_1602();void write_com1602(uchar com);void write_date1602(uchar date);//====================================void delayms(uint time)//毫秒級(jí)延時(shí)函數(shù){uint i,j;for(i=time;i>0;i--)for(j=110;j>0;j--);}void delayus(uint time)//微秒級(jí)延時(shí)函數(shù){while(time--);}void init_18b20()//對(duì)sd18b20的初始化{uchar n;DQ=1;delayus(8);DQ=0;delayus(80);DQ=1;delayus(8);n=DQ;delayus(8);}/*將數(shù)據(jù)線拉為低電平產(chǎn)生寫時(shí)間片，在數(shù)據(jù)線口拉為低電平在15微秒到60微秒間對(duì)數(shù)據(jù)線進(jìn)行數(shù)據(jù)采樣.如果為高電平則為寫“1”，如果為低電平則為寫零。對(duì)于主機(jī)產(chǎn)生的寫“1”時(shí)間片的情況：數(shù)據(jù)線必須必先拉為低電平，然后被釋放，是數(shù)據(jù)線在產(chǎn)生時(shí)間片15微秒之內(nèi)拉至高電平；對(duì)于主機(jī)產(chǎn)生的寫“0”時(shí)間片的情況：數(shù)據(jù)線必須被拉至邏輯電平并且保持低電平60個(gè)微秒*/void write_18b20(uchar com){uint i;for(i=0;i<8;i++){DQ=0;//delayus(4);DQ=com&0x01;delayus(10);DQ=1;com>>=1;delayus(4);}delayus(4);}/*從ds18b20讀數(shù)據(jù)時(shí)，主機(jī)產(chǎn)生讀時(shí)間片。當(dāng)主機(jī)把數(shù)據(jù)線從邏輯高電平拉至低電平時(shí)，產(chǎn)生讀時(shí)間片。數(shù)據(jù)線必須保持在邏輯低電平至少1個(gè)微秒。來至ds18b20的數(shù)據(jù)在讀時(shí)間下降沿之后15微秒有效。因此，為了讀出從時(shí)間片開始15微秒的狀態(tài)，主機(jī)必須停止保持?jǐn)?shù)據(jù)線為邏輯低電平。*/uchar read_18b20(){uint i;uchar date=0x00;for(i=0;i<8;i++){DQ=0;date>>=1;DQ=1;if(DQ)date|=0x80;delayus(4);DQ=1;delayus(4);}return date;}void wendu(){init_18b20();write_18b20(0xcc);//跳過ROMwrite_18b20(0x44);//啟動(dòng)溫度測(cè)量delayus(300);init_18b20();write_18b20(0xcc);//跳過ROMwrite_18b20(0xbe);//讀取溫度low=read_18b20(); //先讀低八位high=read_18b20();//后讀高八位}void xianshi(){uchar a,b,c,d;float m,n=0.0625;high<<=4;high+=(low&0xf0)>>4;m=(low%10)*n;delayus(4);write_com1602(0x80+0x03);a=high/10;                //顯示十位上的數(shù)write_date1602(0x30+a);delayms(5);write_com1602(0x80+0x04);b=high%10;                //顯示個(gè)位上的數(shù)write_date1602(0x30+b);delayms(5);write_com1602(0x80+0x06);c=(int)(m*10);     //小數(shù)點(diǎn)后一位write_date1602(0x30+c);delayms(5);d=(int)(m*100)%10;    //小數(shù)點(diǎn)后第二位write_com1602(0x80+0x07);write_date1602(0x30+d);delayms(5);write_com1602(0x80+0x08);write_date1602(0x27);delayms(5);write_com1602(0x80+0x09);write_date1602(C);delayms(5);write_com1602(0x80+0x05);write_date1602(0x2e);delayms(5);  }void main(){init_1602();while(1){wendu();xianshi();}}void init_1602(){en=0;rw=0;write_com1602(0x28);delayms(5);write_com1602(0x01);delayms(5);write_com1602(0x0c);delayms(5);write_com1602(0x06);delayms(5);}void write_com1602(uchar com){uchar gao,di;gao=com&0xf0;di=(com<<4)&0xf0;delayms(5);P2=gao;rs=0;delayms(5);en=1;delayms(5);en=0;delayms(5);P2=di;rs=0;delayms(5);en=1;delayms(5);en=0;delayms(5);}void write_date1602(uchar date){uchar gao,di;gao=date&0xf0;di=(date<<4)&0xf0;delayms(5);P2=gao;rs=1;delayms(5);en=1;delayms(5);en=0;delayms(5);P2=di;rs=1;delayms(5);en=1;delayms(5);en=0;delayms(5);}