import RPi.GPIO as GPIO
import time

TRIG_PIN = 2
ECHO_PIN = 4
BUZZER_PIN = 5
WATER_LEVEL_THRESHOLD = 30

GPIO.setmode(GPIO.BCM)
GPIO.setup(TRIG_PIN, GPIO.OUT)
GPIO.setup(ECHO_PIN, GPIO.IN)
GPIO.setup(BUZZER_PIN, GPIO.OUT)

try:
    while True:
        # Trigger the ultrasonic sensor
        GPIO.output(TRIG_PIN, False)
        time.sleep(0.2)  # Wait for sensor to settle
        GPIO.output(TRIG_PIN, True)
        time.sleep(0.00001)
        GPIO.output(TRIG_PIN, False)

        # Read the echo pulse duration
        while GPIO.input(ECHO_PIN) == 0:
            pulse_start = time.time()
        while GPIO.input(ECHO_PIN) == 1:
            pulse_end = time.time()

        pulse_duration = pulse_end - pulse_start

        # Convert the duration to distance (in centimeters)
        distance = (pulse_duration * 34300) / 2  # Speed of sound is 343 m/s, and there and back journey

        print("Distance: {:.2f} cm".format(distance))

        # Check if the water level is below the threshold
        if distance < WATER_LEVEL_THRESHOLD:
            # Water level is below the threshold, sound the buzzer
            GPIO.output(BUZZER_PIN, GPIO.HIGH)
        else:
            # Water level is above the threshold, turn off the buzzer
            GPIO.output(BUZZER_PIN, GPIO.LOW)

        time.sleep(1)  # Delay to avoid continuous readings

except KeyboardInterrupt:
    GPIO.cleanup()