树莓派4b——GPIO按键事件触发

喜欢ヅ旅行 2022-12-13 11:18 284阅读 0赞

# 功能需求 #

定义8个GPIO按键，要求每个按键都不影响主程序的运行。只有当按键被按下时树莓派检测到高电平、触发中断，并将被按下的按键的编号输出。

# 设计方案 #

## add\_event\_detect ##

使用`add_event_detect`函数添加触发事件。

## setup ##

使用`setup`函数一次性配置多个GPIO

参考代码如下：

# -*- coding: utf-8 -*- 
    import RPi.GPIO as GPIO    
    
    KEY1 = 1
    KEY2 = 2
    KEY3 = 3
    KEY4 = 4
    KEY5 = 5
    KEY6 = 6
    KEY7 = 7
    KEY8 = 8
    
    ## Initial key I/O
    GPIO.setmode(GPIO.BCM)
    GPIO.setwarnings(False)
    keyChannel = [KEY1,KEY2,KEY3,KEY4,KEY5,KEY6,KEY7,KEY8]
    GPIO.setup(keyChannel, GPIO.IN)
    
    def keyCallback(key):
        if key == KEY1:
            keyStatus = 'KEY1'
        elif key == KEY2:
            keyStatus = 'KEY2'
        elif key == KEY3:
            keyStatus = 'KEY3'
        elif key == KEY4:
            keyStatus = 'KEY4'
        elif key == KEY5:
            keyStatus = 'KEY5'
        elif key == KEY6:
            keyStatus = 'KEY6'
        elif key == KEY7:
            keyStatus = 'KEY7'        
        elif key == KEY8:
            keyStatus = 'KEY8'
        print(keyStatus)
    
    # Key I/O interrupt
    GPIO.add_event_detect(KEY1, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY2, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY3, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY4, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY5, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY6, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY7, GPIO.RISING, callback=keyCallback, bouncetime=200)
    GPIO.add_event_detect(KEY8, GPIO.RISING, callback=keyCallback, bouncetime=200)
                
    if __name__ == '__main__':
        while True:
            continue