text: import RPi.GPIO as GPIO
  import time
  
  GPIO.setmode(GPIO.BCM)
  
  GPIO.setup(18, GPIO.OUT)
  
  p = GPIO.PWM(18, 50)
  
  p.start(7.5)
  p.ChangeDutyCycle(7.5) 
  time.sleep(1)
  p.ChangeDutyCycle(2.5) 
  time.sleep(1)
  p.ChangeDutyCycle(12.5) 
  p.stop()
  GPIO.cleanup()