DHT11温湿度传感器驱动程序 C51单片机

/**************DHT11 简单应用显示在数码管上（我的数码管是两个74HC595 不懂的可以问我）***************

******************建议显示在液晶上******************/

#include

#include

char T_H1,T_L1,RH_H1,RH_L1,checkdata1;

char T_H2,T_L2,RH_H2,RH_L2,checkdata2;

char F16T,F16RH,tshi,tge,rhshi,rhge;

sbit DHT11 = P2^1;

uchar bdata output;

uchar location,j,i,ge,shi;

uint num=0,num1,num2;

uchar code segment[]={

0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77, /*共阴7段LED段码表*/

0x7c,0x39,0x5e,0x79,0x71,0x76,0x73,0x3e,0x00};

sbit srclk=P4^2;

sbit rclk = P4^1;

sbit ser = P4^4;

sbit out_put= output^7;

/*传感器接受数据的响应命令*/

void delay(uint x);

void Delay32us();

void Delay22ms();

void Delay500ms();

void shumaguan(uchar wei,uchar duan)

{

output = wei;

for(j=0;j<8;j++) //位码

{

ser = out_put;

srclk=0;srclk=1;srclk=0;

output = _crol_(output,1);

}

output = duan; //段码

for(j=0;j<8;j++)

{

ser=out_put;

srclk=0;srclk=1;srclk=0;

output = output<<1;

}

rclk=0;rclk=1;rclk=0;

}

void shuru()

{

num=0;

while(num<1000)

{

shumaguan(0x01,~segment[tshi]);

shumaguan(0x02,~segment[tge]);

shumaguan(0x10,~segment[rhshi]);

shumaguan(0x20,~segment[rhge]);

shumaguan(0,~segment[19]);

}

}

char COM(void)

{

char i,temp,comdata;

/**判断信号时0还是1**/

for(i=0;i<8;i++)

{

while(!DHT11);

Delay32us();

temp=0;

if(DHT11)

{

temp=1;

}

//当DHT11变为低电平时，开始下bit 的传送comdata = comdata<<1;

comdata = comdata|temp;

while(DHT11);

}

return comdata;

}

/***主机的开始信号和从机的响应信号***/

/***********DHT11的主函数*********************/

void getDHT11()

{

DHT11=0;

Delay22ms(); //主机拉低22ms

DHT11=1;

Delay32us(); //总线由上拉电阻拉高主机延时20-40us //判断从机是否有低电平响应信号如不响应则跳出，响应则向下运行

if(!DHT11) //T !

{

//判断从机是否发出80us 的低电平响应信号是否结束

while(!DHT11);

//判断从机是否发出80us 的高电平，如发出则进入数据接收状态

while(DHT11);

/*****接收数据的命令每次传送八位******/

RH_H1 = COM();

RH_L1 = COM();

T_H1 = COM();

T_L1 = COM();

checkdata1 = COM();

if(T_H1+T_L1+RH_H1+RH_L1==checkdata1)

{

RH_H2 = RH_H1;

RH_L2 = RH_L1;

T_H2 = T_H1;

T_L2 = T_L1;

F16RH = RH_H2+RH_L2/1000;

F16T = T_H2+T_L2/1000;

tshi = F16T/10;

tge = F16T%10;

rhshi = F16RH/10;

rhge = F16RH%10;

}

}

}

/************主函数*************/

void main()

{

EA = 1 ;

ET0= 1;

TR0 = 1;

TMOD = 0X01;

TH0 = (65536-1000)/256;

TL0 = (65536-1000)%256;

while(1)

{

DHT11=0;

getDHT11();

shuru();

}

}

/**********延时子程序************************/

void time1() interrupt 1 //延时20微秒{

TH0 = (65536-1000)/256;

TL0 = (65536-1000)%256;

num=num+1;

num1=num1+1;

num2=num2+1;

}

void Delay32us() //@12.000MHz

{

unsigned char i;

_nop_();

_nop_();

i = 93;

while (--i);

}

void Delay22ms() //@12.000MHz

{

unsigned char i, j, k;

_nop_();

_nop_();

i = 2;

j = 1;

k = 201;

do

{

do

{

while (--k);

} while (--j);

} while (--i);

}

/*******************************/