1、DHT11简介ui
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。
spa
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 |
2、DHT11模块特色code
1. 能够检测周围环境的湿度和温度。htm
2. 湿度测量范围:20% - 95%(0 度-50 度范围)湿度测量偏差:+-5%。4. 工做电压3.3V - 5V。blog
5. 输出形式数字输出。
接口
6. 单线制串行接口。
ci
3、DHT11原理图get
4、程序it
#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; } } }