from machine import Pin, time_pulse_us
import time

# Pins
trig = Pin(3, Pin.OUT)
echo = Pin(2, Pin.IN)
led = Pin(15, Pin.OUT)

def get_distance():
    # Send trigger pulse
    trig.low()
    time.sleep_us(2)
    trig.high()
    time.sleep_us(10)
    trig.low()

    # Read echo pulse duration
    duration = time_pulse_us(echo, 1)

    # Distance in meters
    distance = (duration * 0.000343) / 2
    return distance

while True:
    dist = get_distance()
    print("Distance:", dist, "meters")

    if dist <= 3:
        led.value(1)  # ON
    else:
        led.value(0)  # OFF

    time.sleep(0.2)