from machine import Pin, time_pulse_us
import time

trig_pin = Pin(27, Pin.OUT)
echo_pin = Pin(26, Pin.IN)

led_red = Pin(25, Pin.OUT)

def measure_distance():
    trig_pin.off()
    time.sleep_us(2)
    trig_pin.on()
    time.sleep_us(10)
    trig_pin.off()

    pulse_duration = time_pulse_us(echo_pin, 1, 30000)
    distance_cm = (pulse_duration / 2) / 29.1
    return distance_cm

while True:
    distance = measure_distance()
    print("Distance:", distance, "cm")

    if (distance < 200):
        led_red.value(1)
        time.sleep(1)
    if (distance > 201):
        led_red.value(0)
        time.sleep(1)