# LIBRARY IMPORTS
from machine import *
from time import *

# LDR SETUP
led = Pin(15, Pin.OUT)
ldr = ADC(Pin(27))
sensor_voltage = 3.3

led.value(0)

# ULTRASONIC SETUP
trig = Pin(11, Pin.OUT)
echo = Pin(13, Pin.IN)
led = Pin(15, Pin.OUT)
buzzer = PWM(Pin(20))
buzzer.freq(1000)

while True:

    light = ldr.read_u16()
    V = (light / 65535) * sensor_voltage

    if V > 1.5:        # DAY
        led.value(1)
        buzzer.duty_u16(0)
        sleep(0.25)
        continue
    else:              # NIGHT
        led.value(0)
        
    trig.value(0)
    sleep_us(2)
    trig.value(1)
    sleep_us(10)
    trig.value(0)

    duration = time_pulse_us(echo, 1)
    distance = (duration * 0.0343) / 2

    if distance > 80:
        led.value(0)
        buzzer.duty_u16(0)

    elif distance >= 30 and distance <= 80:
        led.value(1)
        buzzer.duty_u16(0)

    else:
        led.value(1)
        buzzer.duty_u16(20000)

    sleep(0.8)