from machine import Pin,PWM,Timer
from time import sleep_ms
from HCSR04 import HCSR04
S1=PWM(Pin(16),freq=50,duty=128)
trig=Pin(14,Pin.OUT)
echo=Pin(12,Pin.IN)
HC=HCSR04(trig,echo)

def rotate(servo,degree):
    servo.duty(int(degree*0.54+25.6))
 
def fun(tim):
    distance=HC.getDistance()   
    print(distance)

    if distance>2 and distance<=180:
        rotate(S1,distance)
    else:
        rotate(S1,180)
tim=Timer(1)
tim.init(period=500,mode=Timer.PERIODIC,callback=fun)