from machine import Pin, time_pulse_us
import utime

# Define ultrasonic sensor pins
trigger_pin = Pin(2, Pin.OUT)
echo_pin = Pin(3, Pin.IN)

# Define LED pin
led_pin = Pin(27, Pin.OUT)

# Function to measure distance using ultrasonic sensor
def measure_distance():
    trigger_pin.off()
    utime.sleep_us(2)
    trigger_pin.on()
    utime.sleep_us(5)
    trigger_pin.off()
    pulse_time = time_pulse_us(echo_pin, 1, 30000)
    distance_cm = (pulse_time / 2) / 29.1  # Speed of sound is 343 meters/second

    return distance_cm

# Main loop
while True:
    distance = measure_distance()

    if distance > 70:
        led_pin.on()
    else:
        led_pin.off()