text: #!/usr/bin/python3
  
  import argparse
  import RPi.GPIO as GPIO
  import time
  
  #rpi_pow = 17
  esp_en = 17
  esp_boot = 27
  
  parser = argparse.ArgumentParser(description='Enable Boot mode for programming ESP.')
  parser.add_argument('duration', metavar='N', type=int, nargs='?', default=1,
                      help='duration in seconds')
  
  args = parser.parse_args()
  duration = args.duration
  
  GPIO.setmode(GPIO.BCM)
  
  #GPIO.setup(rpi_pow, GPIO.OUT) 
  #GPIO.setup(esp_en,   GPIO.OUT) 
  GPIO.setup(esp_boot, GPIO.OUT) 
  
  for i in range(duration):
      GPIO.output(esp_boot, 0)
      print(duration - i, "seconds to elapsed ...")
      time.sleep(1)
  
  
  GPIO.setup(esp_boot, GPIO.IN) 
  #GPIO.setup(esp_en, GPIO.OUT) 
  #GPIO.output(esp_en, 0)
  #time.sleep(3)
  
  GPIO.cleanup()
  