一、接线

树莓派 DHT11
3.3V –> VCC
GPIO4 –> DTA
GND –> GND

二、安装Python库

sudo pip3 install Adafruit_DHT

三、Python程序读取温度

import Adafruit_DHT
import time
humidity, temperature = Adafruit_DHT.read_retry(Adafruit_DHT.DHT11, 4) #GPIO 4
while 1 :
    if humidity is not None and temperature is not None:
        print('Temp={0:0.1f}*  Humidity={1:0.1f}%'.format(temperature, humidity))
    else:
        print('Failed to get reading. Try again!')

四、C语言版

1. 安装wiringPi

#下载 wiringPi
git clone https://github.com/WiringPi/WiringPi
#编译 wiringPi
cd WiringPi
sudo ./build

2. C文件

#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 = 7; // pin7
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("PIN:%d\n", pinNumber);
 
    if (-1 == wiringPiSetup()) {
        printf("Setup wiringPi failed!");
        return 1;
    }
  
    pinMode(pinNumber, OUTPUT); // set mode to output
    digitalWrite(pinNumber, 1); // output a high level 
 
    printf("Starting...\n");
    while (1) 
    {
        pinMode(pinNumber, OUTPUT); // set mode to output
        digitalWrite(pinNumber, 1); // output a high level 
        delay(3000);
        if (readSensorData())
        {
            printf("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("Sensor dosent ans!\n");
            databuf = 0;
        }
    }
    return 0;
}

3. 编译运行C文件

gcc -Wall -o dht11 dht11.c -lwiringPi
sudo ./dht11