print("Project: Smart Solar Energy Monitoring System")
print("Developed by: Han")
print("Date: 22/4/2025")

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

# === Initialization ===
print("Initializing devices...")

# Initialize I2C for OLED display
i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=20000)
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# Light Sensor (LDR)
ldr = ADC(Pin(34))
ldr.atten(ADC.ATTN_0DB)

# DHT22 sensor (Temperature & Humidity)
dht_sensor = dht.DHT22(Pin(2))

# Relay for controlling appliances
relay = Pin(5, Pin.OUT)

# LEDs (Green and Red)
green_led = Pin(12, Pin.OUT)
red_led = Pin(13, Pin.OUT)

# Buzzer (PWM for audible tone)
buzzer = PWM(Pin(4))  # Buzzer pin using PWM
buzzer.duty(0)  # Initial duty cycle (off)

# Servo Motor (for solar panel adjustment)
servo = PWM(Pin(14), freq=50)

# === Functions ===
def read_ldr():
    value = ldr.read()
    print("LDR value:", value)
    return value

def read_dht():
    try:
        dht_sensor.measure()
        temp = dht_sensor.temperature()
        humidity = dht_sensor.humidity()
        print("Temp:", temp, "Humidity:", humidity)
        return temp, humidity
    except OSError as e:
        print("DHT read error:", e)
        return None, None

def display_data(ldr_value, temp, humidity):
    oled.fill(0)
    oled.text('LDR: {}'.format(ldr_value), 0, 0)
    if temp is not None:
        oled.text('Temp: {}C'.format(temp), 0, 10)
    if humidity is not None:
        oled.text('Humidity: {}%'.format(humidity), 0, 20)
    oled.show()

def control_relay_and_leds(ldr_value):
    if ldr_value > 2000:
        relay.value(1)
        green_led.value(1)
        red_led.value(0)
        print("Relay: ON (good sunlight)")
    else:
        relay.value(0)
        green_led.value(0)
        red_led.value(1)
        print("Relay: OFF (low sunlight)")

def control_buzzer(ldr_value):
    if ldr_value < 1000:
        buzzer.freq(1000)  # Set frequency to 1 kHz
        buzzer.duty(512)   # Half duty cycle (for audible tone)
        print("Buzzer: ON (low light)")
    else:
        buzzer.duty(0)     # Turn off buzzer
        print("Buzzer: OFF")

def control_servo(ldr_value):
    if ldr_value > 2000:
        servo.duty(40)  # Adjust servo to a specific position (based on light intensity)
        print("Servo: Adjusted")
    else:
        servo.duty(0)   # Reset servo position
        print("Servo: Reset")

# === Main Loop ===
while True:
    print("Reading sensors...")
    ldr_value = read_ldr()
    temp, humidity = read_dht()

    print("Updating OLED...")
    display_data(ldr_value, temp, humidity)

    print("Controlling outputs...")
    control_relay_and_leds(ldr_value)
    control_buzzer(ldr_value)
    control_servo(ldr_value)

    print("Waiting...\n")
    time.sleep(2)