import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)
pwm = GPIO.PWM(18, 100)
pwm.start(5)



def update(self, angle):
    angle = 90
    duty = float(angle) / 10.0 + 2.5
    pwm.ChangeDutyCycle(duty)