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

# Define the GPIO pin numbers for the trigger and echo pins
ECHO_PIN = 2
TRIGGER_PIN = 1

# Initialize trigger and echo pins
trigger = Pin(TRIGGER_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)
led = Pin(10, Pin.OUT)

def measure_distance():
    # Ensure trigger is low initially
    trigger.low()
    sleep_us(2)

    # Send a 10 microsecond pulse to the trigger pin
    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:
        # Measure the distance using the imported function
    distance = measure_distance()
    print("Distance: {:.2f} cm".format(distance))
        
        # Wait for 1 second before taking the next measurement
    sleep(1)

#if __name__ == "__main__":
    #main()
    #distance = measure_distance()
    if measure_distance() > 30:
        led.on()
    else:
        led.off()
        sleep(1)
    sleep(1)