通过原生Python获取

  1. #!/usr/bin/python
  2. #-*- coding:utf-8 -*-
  4. import RPi.GPIO as GPIO
  5. import time
  7. channel = 7            #引脚号Pin7
  8. data = []           #温湿度值
  9. j = 0               #计数器
  11. GPIO.setmode(GPIO.BOARD)      #以BOARD编码格式
  13. time.sleep(1)           #时延一秒
  15. GPIO.setup(channel, GPIO.OUT)
  17. GPIO.output(channel, GPIO.LOW)
  18. time.sleep(0.02)        #给信号提示传感器开始工作
  19. GPIO.output(channel, GPIO.HIGH)
  21. GPIO.setup(channel, GPIO.IN)
  23. while GPIO.input(channel) == GPIO.LOW:
  24.     continue
  26. while GPIO.input(channel) == GPIO.HIGH:
  27.     continue
  29. while j < 40:
  30.     k = 0
  31.     while GPIO.input(channel) == GPIO.LOW:
  32.         continue
  34.     while GPIO.input(channel) == GPIO.HIGH:
  35.         k += 1
  36.         if k > 100:
  37.             break
  39.     if k < 8:          #通过计数的方式判断是数据位高电平长短，以置0或1。（此方式有待商榷）
  40.         data.append(0)
  41.     else:
  42.         data.append(1)
  44.     j += 1
  46. print ("sensor is working.")
  47. print (data)              #输出初始数据高低电平
  49. humidity_bit = data[0:8]        #分组
  50. humidity_point_bit = data[8:16]
  51. temperature_bit = data[16:24]
  52. temperature_point_bit = data[24:32]
  53. check_bit = data[32:40]
  55. humidity = 0
  56. humidity_point = 0
  57. temperature = 0
  58. temperature_point = 0
  59. check = 0
  61. for i in range(8):
  62.     humidity += humidity_bit[i] * 2 ** (7 - i)              #转换成十进制数据
  63.     humidity_point += humidity_point_bit[i] * 2 ** (7 - i)
  64.     temperature += temperature_bit[i] * 2 ** (7 - i)
  65.     temperature_point += temperature_point_bit[i] * 2 ** (7 - i)
  66.     check += check_bit[i] * 2 ** (7 - i)
  68. tmp = humidity + humidity_point + temperature + temperature_point       #十进制的数据相加
  70. if check == tmp:                                #数据校验，相等则输出
  71.     print ("temperature : ", temperature, ", humidity : " , humidity)
  72. else:                                       #错误输出错误信息，和校验数据
  73.     print ("wrong")
  74.     print ("temperature : ", temperature, ", humidity : " , humidity, " check : ", check, " tmp : ", tmp)
  76. GPIO.cleanup()                                  #重置针脚

通过Python模块获取

  1. 下载模块

github.com/adafruit/Adafruit_Python_DHT.git

  1. 安装模块
    1. cd Adafruit_Python_DHT
    2. sudo python setup.py install
    安装完成后进入examples文件夹运行AdfruitDHT.py可以获得结果。
    1. cd examples
    2. Python AdafruitDHT.py 11 24
    后面两个数值11代表使用的是DHT11模块，24代表着所接的GIPO引脚编号（BCM）。

    在Python中使用该模块

    ```python import Adafruit_DHT

Set sensor type : Options are DHT11,DHT22 or AM2302

sensor=Adafruit_DHT.DHT11

Set GPIO sensor is connected to

GPIO=24

Use read_retry method. This will retry up to 15 times to

get a sensor reading (waiting 2 seconds between each retry).

humidity, temperature = Adafruit_DHT.read_retry(sensor, GPIO)

Reading the DHT11 is very sensitive to timings and occasionally

the Pi might fail to get a valid reading. So check if readings are valid.

if humidity is not None and temperature is not None: print(‘Temp={0:0.1f}*C Humidity={1:0.1f}%’.format(temperature, humidity)) else: print(‘Failed to get reading. Try again!’) ```