from machine import Pin, ADC
from time import sleep, ticks_us
from wokwi_lcd2004 import LCD2004  # Import the parallel LCD library

# Ultrasonic sensor setup
trigger = Pin(16, Pin.OUT)
echo = Pin(17, Pin.IN)

# Buzzer setup
buzzer = Pin(18, Pin.OUT)

# Temperature sensor setup
temp_sensor = ADC(Pin(26))  # Using GP26 (ADC0) for the analog temperature sensor

# LED setup for temperature alert
led = Pin(19, Pin.OUT)

# LCD setup with parallel connections to the ESP32 pins
lcd = LCD2004(
    rs=Pin(12),  # Register Select (RS)
    rw=Pin(13),  # Read/Write (RW)
    e=Pin(14),   # Enable (E)
    d4=Pin(32),  # Data Pin 4
    d5=Pin(33),  # Data Pin 5
    d6=Pin(25),  # Data Pin 6
    d7=Pin(26)   # Data Pin 7
)

# Thresholds
WATER_LEVEL_THRESHOLD = 10  # cm
TEMP_THRESHOLD = 30  # degrees Celsius

# Function to measure distance using ultrasonic sensor
def get_distance():
    # trigger pulse
    trigger.low()
    sleep(0.02)
    trigger.high()
    sleep(0.00001)  # 10 microseconds pulse
    trigger.low()

    # Wait for echo response, add error handling
    signal_off = signal_on = 0
    timeout = 30000  # microseconds timeout to avoid infinite loop
    while echo.value() == 0:
        signal_off = ticks_us()
        if ticks_us() - signal_off > timeout:
            return None  # Timeout error
    
    while echo.value() == 1:
        signal_on = ticks_us()
        if ticks_us() - signal_on > timeout:
            return None  # Timeout error

    # Calculate pulse duration and distance
    time_passed = signal_on - signal_off
    distance = (time_passed * 0.0343) / 2  # convert time to distance (cm)
    return distance

# Function to read temperature in Celsius
def read_temperature():
    analog_value = temp_sensor.read_u16()  # Using 16-bit ADC for accuracy
    voltage = (analog_value / 65535) * 3.3  # Convert to voltage based on 3.3V
    temperature = (voltage - 0.5) * 100  # Adjust based on sensor specs
    return temperature

# Function to control the buzzer
def trigger_buzzer(state):
    buzzer.value(state)  # state is 1 for ON and 0 for OFF

# Function to blink LED for temperature alert
def blink_led():
    led.value(1)
    sleep(0.5)
    led.value(0)
    sleep(0.5)

# Main loop
while True:
    # Measure water level
    distance = get_distance()
    if distance is not None:
        # Check water level and control buzzer
        if distance <= WATER_LEVEL_THRESHOLD:
            print(f"Water level: {distance:.1f} cm - ALERT!")
            trigger_buzzer(1)  # turn the buzzer ON
        else:
            print(f"Water level: {distance:.1f} cm")
            trigger_buzzer(0)  # turn the buzzer OFF
    else:
        print("Error: Ultrasonic sensor timeout")

    # Measure temperature
    temperature = read_temperature()
    if temperature >= TEMP_THRESHOLD:
        print(f"Temperature: {temperature:.1f} °C - ALERT!")
        blink_led()  # Blink the LED if temperature is too high
    else:
        print(f"Temperature: {temperature:.1f} °C")
        led.value(0)  # Ensure LED is off when temperature is normal

    # Update LCD display
    lcd.clear()  # Clear the display before updating
    lcd.set_cursor(0, 0)  # Move cursor to the first line
    lcd.print(f"Temp: {temperature:.1f}C")  # Display temperature
    lcd.set_cursor(0, 1)  # Move cursor to the second line
    lcd.print(f"Water: {distance:.1f}cm" if distance is not None else "Water: Err")  # Display water level

    # Delay of 1 second between readings
    sleep(1)