读取 RFID 标签一次（使用 RFID RC522 芯片）停止线程

Question

我在我的 PI 4B 上运行一些需要多线程的代码。我正在使用事件来管理线程并在出现键盘中断或按下 mainBUtton 时运行的函数时停止它们。

from threading import Thread, Event
import RPi.GPIO as GPIO
from mfrc522 import SimpleMFRC522
import time
import os


def setup():

    GPIO.setwarnings(False)

    GPIO.setmode(GPIO.BOARD)     

    GPIO.setup(relayPin, GPIO.OUT)

    GPIO.setup(ledPinRed, GPIO.OUT)

    GPIO.setup(ledPinGreen, GPIO.OUT)

    GPIO.setup(buzzerPin, GPIO.OUT)

    

    global Buzz 

    Buzz = GPIO.PWM(buzzerPin, 440) 

    GPIO.setup(mainButtonPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)    # set buttonPin to PULL UP INPUT mode

    GPIO.setup(faceRecPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)    # set buttonPin to PULL UP INPUT mode

    discordPing.getTokenID("token.txt")



def action():

    GPIO.output(ledPinRed,GPIO.LOW)

    GPIO.output(ledPinGreen, GPIO.HIGH)

    GPIO.output(relayPin, GPIO.HIGH)

    time.sleep(5)

    GPIO.output(ledPinGreen, GPIO.LOW)

    GPIO.output(relayPin, GPIO.LOW)







def destroy(): 

    GPIO.output(relayPin, GPIO.LOW)

    GPIO.cleanup()



def onPress():

    GPIO.output(relayPin, GPIO.LOW)

    buzzerThread = Thread(target=buzzerLoop)

    buzzerThread.start()

    buzzerThread.join()   

    

def buzzerLoop():

    print("Starting Buzzer")

    Buzz.start(50)

    ringEvent = Event()

    ledThread = Thread(target=ledLoop,args=(ringEvent,))

    rfidThread = Thread(target=rfidReader, args=(ringEvent,))

    rfidThread.start()

    ledThread.start()

    for i in range(1, len(song)):

        Buzz.ChangeFrequency(song[i])

        time.sleep(beat[i]*0.13)

    Buzz.stop()

    ringEvent.set()

    ledThread.join()

    #rfidThread.join()





def ledLoop(ringEvent):

    print("Starting LED")

    while True:

        if ringEvent.is_set():

            break

        else:

            GPIO.output(ledPinRed, GPIO.LOW)

            time.sleep(.75)

            GPIO.output(ledPinRed, GPIO.HIGH)

            time.sleep(.75)

    

def loop(event):

    while True:

        if event.is_set():

            print("Button Functionality Shutting Down")

            break

        else:

            if GPIO.input(mainButtonPin)==GPIO.LOW:

                print("Main BUtton Pressed")    

                onPress()

            elif GPIO.input(faceRecPin)==GPIO.LOW:

                print("starting face-rec")

                fullFaceRecognition(event)

            else : 

                pass

                #GPIO.output(ledPinRed,GPIO.HIGH)
def openFile(filename):

    with open(filename, "r") as file:

        lines = len(file.readlines())

        file.seek(0)

        for x in range(lines):

            code = (file.readline()).strip('\n')

            listOfCodes.append(code)

def rfidReader(event):

    reader = SimpleMFRC522()   

    code = ''

    count = 0

    while True:

        if event.is_set():

            print("RFID Shutting Down")

            break

        print(f"Starting RFID - ID#{count}")

        code = reader.read_id()

        print(f"Read {count}")

        count += 1

        if code != '':

            read = False

            for x in listOfCodes:

                if x == str(code):

                    print("Valid Code - Unlocking")

                    '''action()'''

                    code = ''

                    read = True

                    #time.sleep(3)

                    break

                else:

                    pass

            if read == False:

                code = ''

                print("Invalid User")

relayPin = 36

ledPinRed = 11

ledPinGreen = 13

mainButtonPin = 31

faceRecPin = 32

buzzerPin = 37 

mainEvent = Event()

#Main Code

if __name__ == '__main__':

    try:
        setup()

        mainLoopThread = Thread(target=loop, args=(mainEvent,))

        mainLoopThread.start()

        mainLoopThread.join()


    except KeyboardInterrupt:
        print("Program Ended")
        mainEvent.set()
        destroy()

虽然这可能很明显，但我认为它仍然很重要，但主按钮和 RFID 标签需要多次使用，所以目标是在读取一个 RFID 标签后不要让 mainLoop 停止，而是要有能力保持循环 if 语句。

代码输出

Main BUtton Pressed
Starting Buzzer
Starting LED
Starting RFID - ID#0
Read 0
Valid Code - Unlocking
RFID Shutting Down
Button Functionality Shutting Down

在此之后，由于循环被破坏，按钮不起作用。