import time
import RPi.GPIO as GPIO

#IO 
PWM_PIN = 14
PWM_FREQ = 50

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(PWM_PIN, GPIO.OUT)

pwm = GPIO.PWM(PWM_PIN, PWM_FREQ)
pwm.start(0)

try:
	while True:
		for dc in range(0, 90, 5):
			pwm.ChangeDutyCycle(dc)
			time.sleep(0.5)

except KeyboardInterrupt:
	pass
p.stop()
GPIO.cleanup()