树莓派与MQ2气体烟雾传感器的示例分析

VCC <---> 1      #3.5V

GND <---> 6

DO   <---> 7

代码

#!/usr/bin/env  python

# encoding: utf-8

'''

该程序每 1 秒测试一次空气污染，用ctrl+c停止。

http://blog.csdn.net/ling3ye/article/details/51472533

接线图:

VCC <---> 1  #3.5V

GND <---> 6

DO   <---> 7

'''

import RPi.GPIOasGPIO

import time

CHANNEL=7

GPIO.setmode(GPIO.BOARD)

GPIO.setup(CHANNEL, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

defaction(pin):

  print'Sensor  detected action!'

GPIO.add_event_detect(CHANNEL, GPIO.RISING)

GPIO.add_event_callback(CHANNEL,  action)

try:

  whileTrue:

     print'alive'

     time.sleep(0.5)

exceptKeyboardInterrupt:

  GPIO.cleanup()