python - 按钮 GPIO.FALLING 事件被触发两次

Question

这是我第一次尝试在面包板上编写 Raspberry Pi 和硬件按钮的代码。程序很简单，当检测到按下按钮时，打开面包板上的 LED 1 秒钟。我的代码似乎有效，但奇怪的是，每隔一段时间按下一个按钮就会触发回调函数两次。我是一个完全的编程菜鸟，所以我不确定问题是否出在我的代码上，或者硬件或按钮是否以某种方式实际上下降了两次。我希望这里有人可以帮助我解决这个问题。这是我的代码:

#!/usr/bin/env python
import RPi.GPIO as GPIO
import time


LedPin = 11    # pin11 --- led
BtnPin = 12    # pin12 --- button

def setup():
    GPIO.setmode(GPIO.BOARD)       # Numbers GPIOs by physical location
    GPIO.setup(LedPin, GPIO.OUT)   # Set LedPin's mode is output
    GPIO.setup(BtnPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)    # Set BtnPin's mode is input, and pull up to high level(3.3V)
    GPIO.output(LedPin, GPIO.HIGH) # Set LedPin high(+3.3V) to off led

def Light(ev=None):
        print 'A button press was detected'
        GPIO.output(LedPin, 0)  # switch led status on
        time.sleep(1)
        GPIO.output(LedPin, 1)  # switch led status off

def loop():
    GPIO.add_event_detect(BtnPin, GPIO.FALLING, callback=Light) # wait for Button Press (GPIO Falling)
    while True:
        pass   # Don't do anything, sit forever 

def destroy():
        GPIO.output(LedPin, GPIO.HIGH)     # led off
        GPIO.cleanup()                     # Release resource

if __name__ == '__main__':     # Program start from here
    setup()
    try:
        loop()
    except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
        destroy()

Answer 1

尝试为您的事件检测调用添加去抖动值。单位为毫秒。

GPIO.add_event_detect(BtnPin, GPIO.FALLING, callback=Light, bouncetime = 250)