from machine import Pin, I2C, PWM
import ssd1306 
import dht
from time import sleep

# Pin definitions
buzzer_pin = 25 # Pin connected to buzzer
servo_pin = 18 # Pin connected to servo motor
dht_pin = 27 # Pin connected to DHT sensor
relay_pin = 14 # Pin connected to relay module

# Initialize , servo motor, SSD1306 OLED display and buzzer
servo = PWM(Pin(servo_pin), freq=50, duty=77)
i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=10000)
oled = ssd1306.SSD1306_I2C(128, 64, i2c)
buzzer = PWM(Pin(buzzer_pin), freq=10000, duty=0)

# Initialize DHT sensor
dht_sensor = dht.DHT22(Pin(dht_pin))   


# Function to read temperature and humidity from DHT sensor
def read_sensor():
        dht_sensor.measure()
        temperature = dht_sensor.temperature()
        humidity = dht_sensor.humidity()
        return temperature, humidity

# Function to control the relay (turn on/off exhaust fan)
def control_fan(state):
    fan_pin = Pin(relay_pin, Pin.OUT)
    fan_pin.value(state)

# Function to adjust servo position (open/close fan shutter)
def adjust_servo(angle):
    duty = 77 + int(angle / 18)  # Map angle to servo duty
    servo.duty(duty)

# Function to sound buzzer
def buzz():
    buzzer.duty(500) 
    sleep(0.1)
    buzzer.duty(0) 


# Main loop
while True:
    # Read temperature and humidity
    temp, humid = read_sensor()
    
    # Display temperature and humidity on OLED display
    oled.fill(1)
    oled.text("Temp: {:.1f} C".format(temp),5, 10, 0)
    oled.text("Humidity: {:.1f}%".format(humid),5, 20, 0)
    oled.show()
    print("Temperature: {:.1f} C".format(temp))
    print("Humidity: {:.1f}%".format(humid))

    # Check if temperature or humidity exceeds thresholds
    if temp > 30 or humid > 60:
        # Turn on fan and open shutter
        control_fan(1) # State relay on
        adjust_servo(270)  # Open shutter fully
        #display fan shutter open
        oled.text("-----------------", 0, 30, 0)
        oled.text("FAN OPEN !!", 5, 40, 0)
        oled.text("-----------------", 0, 50, 0)
        oled.show()
        buzz()  # Sound buzzer for alert
    else:
        # Turn off fan and close shutter
        control_fan(0) # State relay off
        adjust_servo(0)  # Close shutter fully
        #display fan shutter closed
        oled.text("-----------------", 0, 30, 0)
        oled.text("FAN CLOSED!!", 5, 40, 0)
        oled.text("-----------------", 0, 50, 0)
        oled.show()
        buzzer.duty(0)
    
    
    # Delay before next reading
    sleep(900)