from time import sleep
from machine import Pin
from gpio_lcd import GpioLcd
from hcsr04 import HCSR04

led = Pin(28)
led.off()

buzzer = Pin(6)
buzzer.off()

lcd = GpioLcd(rs_pin=Pin(26),
              enable_pin=Pin(22),
              d4_pin=Pin(21),
              d5_pin=Pin(20),
              d6_pin=Pin(19),
              d7_pin=Pin(18),
              num_lines=2, num_columns=16)

lcd.clear()

sensor = HCSR04(trigger_pin=4, echo_pin=3, echo_timeout_us=10000)

# lcd.putstr("ALERT")

while True:
  distance = sensor.distance_cm()
  
  if(distance > 50):
    lcd.putstr("Distance: {}".format(distance))
  
  if(distance < 10):
    led.on()
    lcd.putstr("ALERT")
    buzzer.on()

  # wait
  sleep(0.5)

  # reset
  lcd.clear()
  led.off()
  buzzer.off()