采用现场总线技术设计温度测控系统素材.pptVIP

程序一（具体温度采集程序） 功能：实时采集当前环境温度值，并显示于数码管上。同时，当温度高于某一值时（在这里设为27摄氏度，蜂鸣器便会发出报警）。而当低于该值时，蜂鸣器便自动停止报警。 #include PIC185F458.h #define uchar unsigned char #define uint unsigned int sbit DS=P2^2; uint temp; uchar flag1; sbit dula=P2^6; sbit wela=P2^7; sbit beep=P2^3; unsigned char code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71}; unsigned char code table1[]={0xbf,0x86,0xdb,0xcf,0xe6,0xed,0xfd,0x87,0xff,0xef}; void delay(uint count) //延时 { uint i; while(count) { i=200; while(i0) i--; count--; } } void dsreset(void) //发送复位和初始化命令 { uint i; DS=0; i=103; while(i0)i--; DS=1; i=4; while(i0)i--; } bit tmpreadbit(void) //读一位 { uint i; bit dat; DS=0;i++; DS=1;i++;i++; dat=DS; i=8;while(i0)i--; return (dat); } uchar tmpread(void) //读一个字节数据 { uchar i,j,dat; dat=0; for(i=1;i=8;i++) { j=tmpreadbit(); dat=(j7)|(dat1); } return(dat); } void tmpwritebyte(uchar dat) //向DS18B20里写一位 { uint i; uchar j; bit testb; for(j=1;j=8;j++) { testb=dat0x01; dat=dat1; if(testb) //write 1 { DS=0; i++;i++; DS=1; i=8;while(i0)i--; } else { DS=0; //write 0 i=8;while(i0)i--; DS=1; i++;i++; } } } void tmpchange(void) //DS18B20开始转换 { dsreset(); delay(1); tmpwritebyte(0xcc); // address all drivers on bus tmpwritebyte(0x44); // initiates a single temperature conversion } uint tmp() //获取温度值 { 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 display(uint temp) { uchar A1,A2,A2t,A3; A1=temp/100; A2t=temp%100; A2=A2t/10; A3=A2t%10; dula=0; P0=t