<gh_stars>0
import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BOARD)
GPIO.setup(12,GPIO.OUT)
pwm=GPIO.PWM(12,50)
pwm.start(0)
for i in range(100):
	pwm.ChangeDutyCycle(i)
	time.sleep(0.1)
for i in range(100,0,-1):
	pwm.ChangeDutyCycle(i)
	time.sleep(0.2)
