Raspberry Pi 继电器和 Python，如何在不同的功能中关闭和打开继电器？

Question

我是 Raspberry Pi 的新手，正在开发一个 Pi3 程序，该程序将通过 1 通道继电器打开和关闭灌溉泵。

我制作了一个运行良好的函数，它采用延迟变量并启动继电器，然后等待延迟，直到它再次停止继电器。

但是，我还需要能够在另一个功能中打开继电器，并保持打开状态直到用户再次将其关闭，但我似乎无法让它工作。

当我尝试时，继电器没有任何反应（除了正常的有电源指示 LED）。

这是我的工作函数：

#This function switches on the relay for a set period of time, and then shuts it off again
def relay_control(wait_time):

    # Sleeping for a second
    time.sleep(1)

    print("Relay control function")

    # We will be using the BCM GPIO numbering
    GPIO.setmode(GPIO.BCM)

    # Selecting which GPIO to target
    GPIO_CONTROL = 6

    # Set CONTROL to OUTPUT mode
    GPIO.setup(GPIO_CONTROL, GPIO.OUT)

    # Starting the relay
    GPIO.output(GPIO_CONTROL, True)

    # Sleeping for set amount of time
    try:
        time.sleep(wait_time)
    except:
        time.sleep(60)
        print("Setting delay failed, using default 60 seconds")

    # Stopping the relay
    GPIO.output(GPIO_CONTROL, False)

    # Cleanup
    GPIO.cleanup()

然后这两个功能我都试过了，就是不行：

#This function switches on the relay - Doesn't currently work
def relay_on():

    # Sleeping for a second
    time.sleep(1)

    # We will be using the BCM GPIO numbering
    GPIO.setmode(GPIO.BCM)

    # Selecting which GPIO to target
    GPIO_CONTROL = 6

    # Set CONTROL to OUTPUT mode
    GPIO.setup(GPIO_CONTROL, GPIO.OUT)

    #Starting the relay
    GPIO.output(GPIO_CONTROL, False)

    #Logging the event
    logging.basicConfig(format='%(asctime)s %(message)s', filename='/home/pi/GardenBrain/events.log', level=logging.INFO)
    logging.info('Relay has been manually switched on, from functions.py')

    time.sleep(5)

    #Cleanup
    GPIO.cleanup()

#This function switches on the relay off - Doesn't currently work
def relay_off():

    # Sleeping for a second
    time.sleep(1)

    # We will be using the BCM GPIO numbering
    GPIO.setmode(GPIO.BCM)

    # Selecting which GPIO to target
    GPIO_CONTROL = 6

    # Set CONTROL to OUTPUT mode
    GPIO.setup(GPIO_CONTROL, GPIO.OUT)

    #Stopping the relay
    GPIO.output(GPIO_CONTROL, True)

    #Logging the event
    logging.basicConfig(format='%(asctime)s %(message)s', filename='/home/pi/GardenBrain/events.log', level=logging.INFO)
    logging.info('Relay has been manually switched off, from functions.py')

    #Cleanup
    GPIO.cleanup()

任何人都可以看到问题所在并帮助我解决问题吗？

非常感谢任何帮助！

此外，工作功能似乎冻结了我的 Raspberry Pi 一段时间。它全部通过 GPIO 引脚供电，系统有一个 7" 触摸屏显示器（系统通过 USB 供电），提到的 230v 1 通道继电器和一个 Sense Hat。

Answer 1

您应该将代码 GPIO.setmode() 和 GPIO.setup() 移出您的函数，因为它只需要设置一次。

部分代码如下所示：

def relay_on():
    GPIO.output(GPIO_CONTROL, False)

    logging.basicConfig(format='%(asctime)s %(message)s', filename='/home/pi/GardenBrain/events.log', level=logging.INFO)
    logging.info('Relay has been manually switched on, from functions.py')

def relay_off():
    GPIO.output(GPIO_CONTROL, True)

    logging.basicConfig(format='%(asctime)s %(message)s', filename='/home/pi/GardenBrain/events.log', level=logging.INFO)
    logging.info('Relay has been manually switched off, from functions.py')


# The main program setup the GPIO
GPIO_CONTROL = 6
GPIO.setmode(GPIO.BCM)
GPIO.setup(GPIO_CONTROL, GPIO.OUT)

# Get input from user to turn on or off relay
while True:
    data = input("Input 'on'/'off' to turn on/off relay, or 'exit' to end ")
    if data == 'on':
        relay_on()
    elif data == 'off':
        relay_off()
    elif data == 'exit':
        # program end, clean up GPIO
        GPIO.cleanup()

Answer 2

我自己用不同的方式编写函数解决了这个问题。这个效果很好，可以按预期启动和停止继电器。

#This function switches on the relay on or off and expects the argument 'on' or 'off'
def relay_manual(action):

    # Selecting which GPIO to target
    GPIO_CONTROL = 6

    if action == "on":

        # Sleeping for a second
        time.sleep(1)

        # We will be using the BCM GPIO numbering
        GPIO.setmode(GPIO.BCM)

        # Set CONTROL to OUTPUT mode
        GPIO.setup(GPIO_CONTROL, GPIO.OUT)

        #Starting the relay
        GPIO.output(GPIO_CONTROL, True)

        #Logging the event
        logging.basicConfig(format='%(asctime)s %(message)s', filename='/home/pi/GardenBrain/events.log', level=logging.INFO)
        logging.info('Relay has been manually switched on, from functions.py')

    elif action == "off":

        try:
            #Stopping the relay
            GPIO.output(GPIO_CONTROL, False)

        except:
            # We will be using the BCM GPIO numbering
            GPIO.setmode(GPIO.BCM)

            # Set CONTROL to OUTPUT mode
            GPIO.setup(GPIO_CONTROL, GPIO.OUT)

            #Starting the relay
            GPIO.output(GPIO_CONTROL, False)

        #Logging the event
        logging.basicConfig(format='%(asctime)s %(message)s', filename='/home/pi/GardenBrain/events.log', level=logging.INFO)
        logging.info('Relay has been manually switched off, from functions.py')

        #Cleanup
        GPIO.cleanup()

Raspberry Pi 继电器和 Python，如何在不同的功能中关闭和打开继电器？

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