from machine import Pin, PWM, time_pulse_us,
from time import sleep
button = Pin(6, Pin.IN, Pin.PULL_DOWN)
servo = PWM(Pin(11))  
servo.freq(50)  
trigger = Pin(21, Pin.OUT)  
echo = Pin(20, Pin.IN)     
def set_servo_angle(angle):
    
    duty = int(1638 + (angle / 180) * (8192 - 1638))
    servo.duty_u16(duty)
set_servo_angle(0)
def get_distance():
    trigger.low()
    sleep(0.002)
    trigger.high()
    sleep(0.00001)  
    trigger.low()
    duration = time_pulse_us(echo, 1)
    distance_cm = (duration * 0.0343) / 2
    return distance_cm
while True:
    if button.value()==1:
        set_servo_angle(90)
        sleep(5)
        set_servo_angle(0)
        
    if get_distance() < 50 :
        set_servo_angle(90)
        sleep(5)
        set_servo_angle(0)

    sleep(0.1)