if (counter == 20):
                print("1 euro")
            if (counter == 30):
                print("2 euro")
            counter = 0
            count = 1
            print("Ready to process the next payment !")
            time.sleep(1)


def thirdFunction():
    global ts
    while True:
        if (counting == 0):
            ts = time.time()
            time.sleep(1)


try:
    t1 = Thread(target=firstFunction)
    t2 = Thread(target=secondFunction)
    t3 = Thread(target=thirdFunction)
    t1.start()
    t2.start()
    t3.start()
except KeyboardInterrupt:
    t1.stop()
    t2.stop()
    t3.Stop()
    GPIO.cleanup()