基于 51 单片机的 DHT11 温湿度传感器#include#include#define uchar unsigned char#define uint unsigned intsbit dth=P1^0;sbit dula=P2^6;sbit wela=P2^7;uchar s8h,s8h_temp,s8l,s8l_temp,w8h,w8h_temp,w8l,w8l_temp,check8,check8_temp,flag=0;float sd,wd;uchar code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0xbf,0x86,0xdb,0xcf,0xe6,0xed,0xfd,0x87,0xff,0xef};void delayms(uint z){uint x,y;for(x=z;x>0;x--)for(y=110;y>0;y--);}void Delay_10us() //进入函数 3us{ uchar i; //每条语句 1us i--; i--; i--; i--; i--; i--;}void display(uchar th,uchar tl){uchar ih=0,il=0,jh=0,jl=0,kh=0,kl=0;ih=th/100;jh=th%100/10;kh=th%10;il=tl/100;jl=tl%100/10;kl=tl%10;P0=0xfe;wela=1;wela=0;P0=table[ih];dula=1;dula=0; delayms(2);P0=0xfd;wela=1;wela=0;P0=table[jh];dula=1;dula=0;delayms(2);P0=0xfb;wela=1;wela=0;P0=table[kh+10];dula=1;dula=0;delayms(2);P0=0xf7;wela=1;wela=0;P0=table[il];dula=1;dula=0; delayms(2);P0=0xef;wela=1;wela=0;P0=table[jl];dula=1;dula=0;delayms(2);P0=0xdf;wela=1;wela=0;P0=table[kl];dula=1;dula=0;delayms(2);} char com(){uchar i,j,temp,cdata=0;for(i=0;i<8;i++){flag=2;while((!dth)&&(flag++)); //等待拉高//Delay_10us();//Delay_10us();//Delay_10us();j=3;while(j--); //延时 30ustemp=0;if(dth==1)temp=1;flag=2;while(dth&&(flag++));//等待拉低//if(flag==1)break;cdata<<=1;cdata=cdata|temp;}return cdata;}void getdth(){uchar i;dth=0;delayms(18); //18msdth=1;//Delay_10us();//Delay_10us();//Delay_10us();//Delay_10us();i=4;while(i--); //延时 40usdth=1;if(dth!=1) //dth11 响应{flag=2;while((!dth)&&(flag++)); //等待拉高flag=2;while(dth&&(flag++));//等待读入数据s8h_temp=com();s8l_temp=com();w8h_temp=com();w8l_temp=com();check8_temp=com();dth=1;if((s8h_temp+s8l_temp+w8h_temp+w8l_temp)==check8_temp) //校验{ s8h=s8h_temp;s8l=s8l_temp;w8h=w8h_temp;w8l=w8l_temp;check8=check8_temp;}}sd=s8h+(float)s8l/256;wd=w8h+(float)w8l/256;}void main(){while(1){getdth();display(s8h,w8h);}}
