DS18B20温度计C程序.docx
温度值精确到0.1度，1cd1602显示仿真电路图如下:C程序如下：Sinc1ude<reg51.h>Jtdefineucharunsignedchar#defineuintunsignedintsbitDQ=P37"ds18b20与单片机连接口sbitRS=P3'0;sbitRW=P31；sbitEN=P32;unsignedcharcodestr1=temperature:“;“；unsignedcharcodestr2=*uchardatadisdata5;uittva1ue;温度值uchartf1ag;/温度正负标志/*Icd1602程序*/voidde1ay1ms(unsignedintms)延时1亳秒(不够精确的)(unsignedinti,j;for(i=0;i<ms;i÷+)for(j=OJ<IOOJ+);)voidwr_com(unsignedcharCoIn)写指令de1ay1ms(1);RS=0;RW=O;EN=O;P2=com;de1ay1ms(1);EN=I;de1ay1ms(1);EN=O;voidwr_dat(unsignedchardat)写数据C1e1ay1ms(I);RS=I;RW=O:EN=O;P2=dat;de1ay1ms(1);EN=I;de1ay1ms(1);EN=O;voidIC(1init()初始化设置de1ay1ms(15);wr_com(0x38);de1ayIms(5);WjCOm(OX08)Jde1ay1ms(5);wr_com(0x01);de1ay1ms(5);wr_com(0x06);de1ay1ms(5);wr_com(OxOc);de1ay1ms(5);voiddisp1ay(unsignedchar*)显示whi1e(*p!,0,)wrdat(*p)：p+；de1ay1ms(1);)init_p1ay()初始化显示1cd_init();wr_com(0x80);disp1ay(str1);wr_com(OxcO);disp1ay(str2);)*Hs1820J*/voidde1ay_18B20(unsignedinti)延时1微秒(whi1e(i一);)voidds1820rst()/*d$1820复位*/unsignedcharx=0;DQ=1;/DQ复位de1ay_18B20(4)延时DQ=0;DQ拉低de1ay_18B20(100);精确延时大于480USDQ=1；拉高de1ay_18B20(40):)uchards1820rd()/*读数据*/(unsignedchari=0;unsignedchardat=0;for(i=8;i>0;i)(DQ=0;给脉冲信号dat>>=1;I)Q=1;给脉冲信号if(DQ)datI=0x80;de1ay_18B20(10);)return(dat);)voidds1820wr(ucharWdata)*写数据*/(unsignedchari=0;for(i=8;i>0;i)DQ=0:DQ=wdata&OxO1;de1ay_18B20(10);DQ=1；wdata>>=1;)read_temp()*读取温度值并转换*/uchara,b;ds1820rst();ds1820wr(Oxcc);*跳过读序列号*/ds1820wr(0x44);*启动温度转换*/ds1820rst();ds1820wr(Oxcc);*跳过读序列号*/ds1820wr(Oxbe);*读取温度*/a=ds1820rd();b=ds1820rd();tva1ue=b;tva1ue<<=8;tva1ue=tva1uea;if(tva1ue<xfff)tfIag=O;e1setva1ue="utva1ue+1;tag=1;)tva1ue=tva1ue*(O.625);温度值扩大10倍，精确到1位小数return(tva1ue);/*/voidds1820disp()温度值显示ucharf1agdat;disdata0=tva1ue/1000+0x30;百位数disdata1=tva1ue%1000100+0x30;十位数disdata2=tva1ue%10010+0x30;/个位数disdata3=tva1ue%10+0x30;小数位if(tfIag=O)f1agdat=0x20;正温度不显示符号e1sef1agdat=0x2d;负温度显示负号:-if(disdata0=0x30)disdata0=0x20;如果百位为0,不显示if(disdata1=0x30)disdata1=0x20;/如果百位为0,卜位为0也不显示)wrcom(OxcO);wrdat(f1agdat);显示符号位wr_com(Oxc1);wr-dat(disdataO);显示百位wr_com(0xc2);WJdat(disdata1);显示H立wr_com(0xc3);wr-dat(disdata2);显示个位wr_com(0xc4);wr_dat(0x2e);显示小数点WjCOnI(OXC5);Wjdat(disdata3);显示小数位)/*主程序*/voidain()init_p1ay();初始化显示whiIe(I)(reademp();读取温度ds1820disp()；显示
