def servo3(tf):
    gpio.setmode(gpio.BCM)
    gpio.setup(20, gpio.OUT)
    p3 = gpio.PWM(20, 50)
    p3.start(6)
    p3.ChangeDutyCycle(tf)
    time.sleep(0.7)
    gpio.cleanup()
def servo3(tf):
    gpio.setmode(gpio.BCM)
    gpio.setup(20, gpio.OUT)
    p3 = gpio.PWM(20, 50)
    p3.start(6)
    p3.ChangeDutyCycle(tf)
    time.sleep(0.7)
    gpio.cleanup()