DHT11测温度湿度（附图）

原器件DHT11
注意正反面
连接方法vcc接3.3v
Dout接GPIO1
NC不接
GND接地
创建脚本mydht11.c
//
//mydht11.c
//
#include <wiringPi.h>
#include <stdio.h>
#include <stdlib.h>

typedef unsigned char uint8;
typedef unsigned int uint16;
typedef unsigned long uint32;

#define HIGH_TIME 32

int pinNumber =1; //use gpio1 to read data
uint32 databuf;



uint8 readSensorData(void)
{
uint8 crc;
uint8 i;

pinMode(pinNumber,OUTPUT); // set mode to output
digitalWrite(pinNumber, 0); // output a high level
delay(25);
digitalWrite(pinNumber, 1); // output a low level
pinMode(pinNumber, INPUT); // set mode to input
pullUpDnControl(pinNumber,PUD_UP);

delayMicroseconds(27);
if(digitalRead(pinNumber)==0) //SENSOR ANS
{
while(!digitalRead(pinNumber)); //wait to high

for(i=0;i<32;i++)
{
while(digitalRead(pinNumber)); //data clock start
while(!digitalRead(pinNumber)); //data start
delayMicroseconds(HIGH_TIME);
databuf*=2;
if(digitalRead(pinNumber)==1) //1

{
databuf++;
}
}

for(i=0;i<8;i++)
{
while(digitalRead(pinNumber)); //data clock start
while(!digitalRead(pinNumber)); //data start
delayMicroseconds(HIGH_TIME);
crc*=2;
if(digitalRead(pinNumber)==1) //1
{
crc++;
}
}
return 1;
}
else
{
return 0;
}
}

int main (void)
{

printf("Use GPIO1 to read data!\n");

if (-1 == wiringPiSetup()) {
printf("Setup wiringPi failed!");
return 1;
}

pinMode(pinNumber, OUTPUT); // set mode to output
digitalWrite(pinNumber, 1); // output a high level
printf("Enter OS-------\n");
while(1) {
pinMode(pinNumber,OUTPUT); // set mode to output
digitalWrite(pinNumber, 1); // output a high level
delay(3000);
if(readSensorData())
{
printf("Congratulations ! Sensor data read ok!\n");
printf("RH:%d.%d\n",(databuf>>24)&0xff,(databuf>>16)&0xff);
printf("TMP:%d.%d\n",(databuf>>8)&0xff,databuf&0xff);
databuf=0;
}
else
{
printf("Sorry! Sensor dosent ans!\n");
databuf=0;
}
}
return 0;
}

编译
gcc -o mydht11 mydht11.c -L/usr/local/lib-lwiringPi
运行
./mydht11
结果
Use GPIO1 to read data!
Enter OS-------
Congratulations ! Sensor data read ok!
RH:35.0
TMP:25.0

pi@raspberrypi:~/Desktop $ ./mydht11
Use GPIO1 to read data!
Enter OS-------
Sorry! Sensor dosent ans!
Congratulations ! Sensor data read ok!
RH:3.73
TMP:1.10
Congratulations ! Sensor data read ok!
RH:6.146
TMP:2.20
Congratulations ! Sensor data read ok!
RH:3.146
TMP:2.20
我的怎么这般低