from machine import Pin, PWM
from time import sleep
from ultra import HCSR04

sensor = HCSR04(trigger_pin=0, echo_pin=1, echo_timeout_us=30000)
buzzer = Pin(3, Pin.OUT)
servo = PWM(Pin(21), freq=50)

def set_servo_angle(angle):

    duty = int((0.025 + (angle / 180) * 0.1) * 65535)
    servo.duty_u16(duty)

while True:
    distance = sensor.distance_cm()
    print("Distance: ", distance, "cm")
    
    if distance >= 350:
        buzzer.value(1)
        set_servo_angle(0)
         
    elif distance >= 100 and distance < 350:
        buzzer.value(0)
        set_servo_angle(45)
        
    else:
        buzzer.value(0)
        set_servo_angle(90)
        
    sleep(1)