import RPi.GPIO as GPIO

import time

sensor = 4

 

GPIO.setmode(GPIO.BCM)

GPIO.setup(sensor, GPIO.IN, GPIO.PUD_DOWN)

 

previous_state = False

current_state = False

 

while True:

      time.sleep(0.1)

      previous_state = current_state

      current_state = GPIO.input(sensor)

      if current_state != previous_state:

          new_state = "HIGH" if current_state else "LOW"

          print("GPIO pin %s is %s" % (sensor, new_state))