import machine
from machine import Pin,PWM
import time,math
from time import sleep
PWM_servo = PWM(Pin(17),freq=50,duty=0)
echo = Pin(2,Pin.IN)
trig = Pin(15,Pin.OUT)
def Servo(servo,angle):
    PWM_servo.duty(int(((angle)/180*2+0.5)/20*1023))
while True:
    trig.value(0)
    time.sleep(0.5)
    trig.value(1)
    time.sleep(0.5)
    trig.value(0)
    x = machine.time_pulse_us(echo,1)
    distance = (0.034 * x) / 2
    tran_dis = '%.2f' %(distance)
    print(f"distance : {tran_dis} cm")
    if distance <= 200:
        Servo(17,90)
    else:
        Servo(17,0)
    time.sleep(2)