from machine import Pin, time_pulse_us
from time import sleep_us, sleep

LED_PIN = 5
ECHO_PIN = 26
TRIGGER_PIN = 27

led = Pin(LED_PIN, Pin.OUT)
trigger = Pin(TRIGGER_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)

def measure_distance():
    trigger.low()
    sleep_us(2)
    trigger.high()
    sleep_us(10)
    trigger.low()

    # Measure the duration of the echo pulse (in microseconds)
    pulse_duration = time_pulse_us(echo, Pin.high)

    # Calculate the distance (in centimeters) using the speed of sound (343 m/s)
    distance = pulse_duration * 0.0343 / 2
    return distance

def main():
    while True:
        distance = measure_distance()
        print("Distance:", distance, "cm")
        
        if distance <= 150:
            led.toggle()
        else:
            led.low()

        sleep(1)

if __name__ == "__main__":
    main()