from machine import Pin, PWM
import time

trig = Pin(5, Pin.OUT)
echo = Pin(18, Pin.IN)
servo = PWM(Pin(13), freq=50)

def set_angle(angle):
    duty = int(26 + (angle / 180.0) * 97)
    servo.duty(duty)

def get_distance():
    trig.value(0)
    time.sleep_us(2)
    trig.value(1)
    time.sleep_us(10)
    trig.value(0)
    
    signaloff = 0
    signalon = 0
    
    while echo.value() == 0:
        signaloff = time.ticks_us()
    while echo.value() == 1:
        signalon = time.ticks_us()
        
    time_passed = time.ticks_diff(signalon, signaloff)
    distance = (time_passed * 0.0343) / 2
    return distance

set_angle(0)

while True:
    dist = get_distance()
    
    if dist < 50:
        print("Person Detected at Gate!")
        set_angle(90)
        time.sleep(3)
        set_angle(0)
        time.sleep(1)
        
    time.sleep(0.1)