#include
#define uint unsigned int
#define uchar unsigned char
sbit TRH = P1^0;//温湿度传感器DHT11数据接入 uchar str[]={0,0,0,0,0,0,0,0};
uint TH,TL,RH,RL,CK;
uint THc,TLc,RHc,RLc,CKc;
uint xh,sum;
// void delay(uchar s) //延时10us // { // uchar v; // for(;s>0;s--) // for(v=25;v>0;v--); // } void delay(uchar b)
//误差 0us {
unsigned char a;
for(;b>0;b--)
for(a=2;a>0;a--); }
//void delay1( )// 延时20ms //{
//uchar x,y,z; //for(x=15;x>0;x--) //for(y=4;y>0;y--) //for(z=248;z>0;z--); //} void delay1(uchar c)
//误差 0us {
unsigned char a,b;
for(;c>0;c--)
for(b=142;b>0;b--)
for(a=2;a>0;a--); }
void delay2()//数码管显示用的延时 {
uchar l,j,k; for(l=2;l>0;l--) for(j=4;j>0;j--) for(k=100;k>0;k--); }
void start() {
TRH=1;
delay(2);
TRH=0; //主机拉低18ms
delay1(20);
TRH=1; //DATA总线由上拉电阻拉高主机延时20
delay(3); }
uchar receive()
{
uchar i,temp;
xh=0;
while(TRH);
for(i=0;i
{ while(!TRH);
delay(3);
if(TRH)
{ temp=1;while(TRH);}
else
temp=0;
xh
xh|=temp;
}
return (xh);
}
void display() { uchar a[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90}; uchar m,n,s,i;
m= str[3];//数码管显示部分
n= str[4];
s= str[5];
while(1)
{ for(i=0;i
m=a[i]; }
P0=m;
P2=0x10;
delay2();
for(i=0;i
n=a[i]; }
P0=n-0X80;
P2=0x20; delay2();
for(i=0;i
s=a[i];
}
P0=s;
P2=0x40; delay2();
P0=0X9C;
P2=0x80; delay2(); }
}
void main()
{
while(1) {
start();
TRH=1;
// 读取数据并写入指令
if(!TRH)
{
while(!TRH); //判断DHT11发出 80us 的低电平响应信号是否结束
while(TRH);
delay(8);
RHc = receive(); //数据接收状态
RLc = receive();
THc = receive();
TLc = receive();
CKc = receive();
}
TRH=1;
sum=(RHc+RLc+THc+TLc);//数据校验
if(sum==CKc)
{
RH = RHc;
RL = RLc;
TH= THc;
TL = TLc;
CK = CKc;
str[0] =RH/10; //湿度整数部分
str[1] =RH%10;
str[2] = RL/10 ;
str[3] = TH/10;
//温度整数部分
display(); }
}
str[4] = TH%10;
str[5] = TL/10;
}
