【转】温湿度传感器---DHT11

只看该作者 · 2016-12-21 19:44

一、DHT11简介

DHT11是一款有已校准数字信号输出的温湿度传感器，传感器包括一个电阻式感湿元件和一个NTC测温元件。

pin	名称	注释
1	VDD	供电 3－5.5V DC
2	DATA	串行数据，单总线
3	NC	空脚，请悬空
4	GND	接地，电源负极

二、DHT11模块特点

1. 可以检测周围环境的湿度和温度。

2. 湿度测量范围：20% - 95%（0 度-50 度范围）湿度测量误差：+-5%。
3. 温度测量范围：0 度 - 50 度温度测量误差：+/-2 度。

4. 工作电压3.3V - 5V。

5. 输出形式数字输出。

6. 单线制串行接口。

三、DHT11原理图

四、程序

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#include <reg52.h>
#include <intrins.h>
typedef unsigned char U8; /* defined for unsigned 8-bits integer variable */
typedef signed char S8; /* defined for signed 8-bits integer variable */
typedef unsigned int U16; /* defined for unsigned 16-bits integer variable */
typedef signed int S16; /* defined for signed 16-bits integer variable */
typedef unsigned long U32; /* defined for unsigned 32-bits integer variable */
typedef signed long S32; /* defined for signed 32-bits integer variable */
typedef float F32; /* single precision floating point variable 32 */
typedef double F64; /* double precision floating point variable 64 */
#define uchar unsigned char
#define uint unsigned int
#define Data_0_time 4
sbit P2_0 = P2^0 ;
U8 U8FLAG,k;
U8 U8count,U8temp;
U8 U8T_data_H,U8T_data_L,U8RH_data_H,U8RH_data_L,U8checkdata;
U8 U8T_data_H_temp,U8T_data_L_temp,U8RH_data_H_temp,U8RH_data_L_temp,U8checkdata_temp;
U8 U8comdata;
U8 outdata[5];
U8 indata[5];
U8 count, count_r = 0;
U8 str[5]={"RS232"};
U16 U16temp1,U16temp2;
void SendData(U8 *a)
{
outdata[0] = a[0];
outdata[1] = a[1];
outdata[2] = a[2];
outdata[3] = a[3];
outdata[4] = a[4];
count = 1;
SBUF = outdata[0];
}
void Delay(U16 j)
{
U8 i;
for(; j > 0; j--)
{
for(i = 0; i < 27; i++);
}
}
void Delay_10us(void)
{
U8 i;
i--;
i--;
i--;
i--;
i--;
i--;
}
void COM(void)
{
U8 i;
for(i = 0; i < 8; i++)
{
U8FLAG = 2;
while((!P2_0) && U8FLAG++);
Delay_10us();
Delay_10us();
Delay_10us();
U8temp = 0;
if(P2_0)U8temp = 1;
U8FLAG = 2;
while((P2_0) && U8FLAG++);
if(U8FLAG == 1)break;
U8comdata<<=1;
U8comdata|=U8temp; //0
}
}
void RH(void)
{
P2_0 = 0;
Delay(180);
P2_0 = 1;
Delay_10us();
Delay_10us();
Delay_10us();
Delay_10us();
P2_0 = 1;
if(!P2_0) //T !
{
U8FLAG = 2;
while((!P2_0) && U8FLAG++);
U8FLAG = 2;
while((P2_0) && U8FLAG++);
COM();
U8RH_data_H_temp = U8comdata;
COM();
U8RH_data_L_temp = U8comdata;
COM();
U8T_data_H_temp = U8comdata;
COM();
U8T_data_L_temp = U8comdata;
COM();
U8checkdata_temp = U8comdata;
P2_0 = 1;
U8temp = (U8T_data_H_temp + U8T_data_L_temp + U8RH_data_H_temp + U8RH_data_L_temp);
if(U8temp == U8checkdata_temp)
{
U8RH_data_H = U8RH_data_H_temp;
U8RH_data_L = U8RH_data_L_temp;
U8T_data_H = U8T_data_H_temp;
U8T_data_L = U8T_data_L_temp;
U8checkdata = U8checkdata_temp;
}
}
}
void main()
{
//uchar str[6]={"RS232"};
TMOD = 0x20;
TH1 = 253;
TL1 = 253;
TR1 = 1;
SCON = 0x50;
ES = 1;
EA = 1;
TI = 0;
RI = 0;
SendData(str);
Delay(1);
while(1)
{
RH();
str[0] = U8RH_data_H;
str[1] = U8RH_data_L;
str[2] = U8T_data_H;
str[3] = U8T_data_L;
str[4] = U8checkdata;
SendData(str);
Delay(20000);
}
}
void RSINTR() interrupt 4 using 2
{
U8 InPut3;
if(TI == 1)
{
TI = 0;
if(count != 5)
{
SBUF = outdata[count];
count++;
}
}
if(RI == 1)
{
InPut3 = SBUF;
indata[count_r] = InPut3;
count_r++;
RI = 0;
if(count_r == 5)
{
count_r = 0;
str[0] = indata[0];
str[1] = indata[1];
str[2] = indata[2];
str[3] = indata[3];
str[4] = indata[4];
P0 = 0;
}
}
}

【转】温湿度传感器---DHT11

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