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#include <reg52.h> #define uchar unsigned char #define uint unsigned int sbit fm=P2^3; sbit DS=P2^2; //define interface 定义连接 uint temp; // variable of temperature 温度变化 uchar flag1; // sign of the result positive or negative 表明结果的正确与否 unsigned char code table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82, 0xf8,0x80,0x90,}; unsigned char code table1[]={0x40,0x79,0x24,0x30,0x19,0x12,0x02, 0x78,0x00,0x10}; void delay(uint count) //delay { uint i; while(count) { i=200; while(i>0) i--; count--; } } void dsreset(void) //send reset and initialization command 重置初始数据 { uint i; DS=0; i=103; while(i>0)i--; DS=1; i=4; while(i>0)i--; } bit tmpreadbit(void) //read a bit 读点 { uint i; bit dat; DS=0;i++; //i++ for delay DS=1;i++;i++; dat=DS; i=8;while(i>0)i--; return (dat); } uchar tmpread(void) //read a byte date 读一个字节数据 { uchar i,j,dat; dat=0; for(i=1;i<=8;i++) { j=tmpreadbit(); dat=(j<<7)|(dat>>1); //读出的数据最低位在最前面，这样刚好一个字节在DAT里 } return(dat); } void tmpwritebyte(uchar dat) //write a byte to ds18b20 { uint i; uchar j; bit testb; for(j=1;j<=8;j++) { testb=dat&0x01; dat=dat>>1; if(testb) //write 1 { DS=0; i++;i++; DS=1; i=8;while(i>0)i--; } else { DS=0; //write 0 i=8;while(i>0)i--; DS=1; i++;i++; } } } void tmpchange(void) //DS18B20 begin change { dsreset(); delay(1); tmpwritebyte(0xcc); // address all drivers on bus tmpwritebyte(0x44); // initiates a single temperature conversion } uint tmp() //get the temperature { float tt; uchar a,b; dsreset(); delay(1); tmpwritebyte(0xcc); tmpwritebyte(0xbe); a=tmpread(); b=tmpread(); temp=b; temp<<=8; //two byte compose a int variable temp=temp|a; tt=temp*0.0625; temp=tt*10+0.5; return temp; } void readrom() //read the serial { uchar sn1,sn2; dsreset(); delay(1); tmpwritebyte(0x33); sn1=tmpread(); sn2=tmpread(); } void delay10ms() //delay { uchar a,b; for(a=10;a>0;a--) for(b=60;b>0;b--); } void display(uint temp) //显示程序 { uchar A0,A1,A2,A2t,A3,ser; ser=temp/10; SBUF=ser; A0=temp/1000; A1=(temp/100)%10; A2t=temp%100; A2=A2t/10; A3=A2t%10; P1=0x01; P0=table[A0];//显示百位 delay(1); P1=0X02; P0=table[A1]; //显示十位 delay(1); P1=0X04; P0=table1[A2]; //显示个位 delay(1); P1=0X08; P0=table[A3]; //显示十分位 delay(1); } void main() { uc har a; do { tmpchange(); // delay(200); for(a=10;a>0;a--) { display(tmp()); if(temp>300|temp<270) fm=0; else fm=1; } }while(1); } 窗体顶端 窗体底端
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