树莓派使用DHT11温湿度传感器（C语言）

硬件：

树莓派 2.0

DHT模块  接树莓派5V GND GPIO1

功能：读取传感器数据并打印出来

//
//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!
");

  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-------
");
  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!
");
       printf("RH:%d.%d
",(databuf>>24)&0xff,(databuf>>16)&0xff);
       printf("TMP:%d.%d
",(databuf>>8)&0xff,databuf&0xff);
       databuf=0;
     }
    else
     {
        printf("Sorry! Sensor dosent ans!
");
       databuf=0;
      }
  }
  return 0;
}