from machine import Pin, time_pulse_us
import utime

TRIG = Pin(20, Pin.OUT)
ECHO = Pin(21, Pin.IN)
LED = Pin(15, Pin.OUT)
  
while True:
    TRIG.low()
    utime.sleep_us(2)
    TRIG.high()
    utime.sleep_us(10)
    TRIG.low()

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

    print("Distance:", distance, "cm")

    if distance > 320:
        LED.on()
    else:
        LED.off()

    utime.sleep(1)