import machine
import network
import time
import urequests
import ujson
import math

# WiFi credentials
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = "<YOUR_WIFI_PASSWORD>"  # Replace with your actual Wi-Fi password

# ThingSpeak API settings
THINGSPEAK_URL = "https://api.thingspeak.com/update"
THINGSPEAK_API_KEY = "FPUENL3IT4CV2A0R"  # Replace with your ThingSpeak API key

# LDR sensor connected to an analog pin (GPIO 27)
LDR_SENSOR_PIN = machine.ADC(27)

# Constants for phototransistor characteristics
GAMMA = 0.7
RL10 = 50  # Resistance at 10 lux in kΩ

# Function to calculate lux based on ADC value
def calculate_lux(raw_adc):
    # Convert ADC value (0 to 65535) to voltage (0 to 5V)
    voltage = (raw_adc / 65535) * 5
    # Calculate resistance based on voltage divider formula
    resistance = 2000 * voltage / (1 - voltage / 5)
    # Calculate lux using the given gamma and RL10
    lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA))
    return lux

# Function to read the LDR sensor
def read_ldr():
    raw_adc = LDR_SENSOR_PIN.read_u16()  # Read raw ADC value
    lux = calculate_lux(raw_adc)  # Convert raw ADC value to lux
    return lux

# Function to send data to ThingSpeak using GET request
def send_data_to_thingspeak(lux):
    # Prepare the URL with the lux value
    url = f"{THINGSPEAK_URL}?api_key={THINGSPEAK_API_KEY}&field1={lux:.2f}"
    
    # Send the GET request
    try:
        response = urequests.get(url)
        print("ThingSpeak Response:", response.text)  # Print the response for debugging
        response.close()
    except Exception as e:
        print("Failed to send data to ThingSpeak:", e)

# Initialize the Wi-Fi connection
wifi = network.WLAN(network.STA_IF)
wifi.active(True)
wifi.connect(WIFI_SSID, WIFI_PASSWORD)

# Wait for the Wi-Fi connection to establish
while not wifi.isconnected():
    print("Connecting to Wi-Fi...")
    time.sleep(1)

print("Connected to Wi-Fi:", wifi.ifconfig())

# Main loop
if __name__ == "__main__":
    try:
        while True:
            lux = read_ldr()  # Read the light intensity in lux
            print(f"Light Intensity (Lux): {lux:.2f}")
            send_data_to_thingspeak(lux)  # Send the lux value to ThingSpeak
            print("Data sent to ThingSpeak")
            time.sleep(5)  # Send data every 5 seconds
    except KeyboardInterrupt:
        print("Program stopped.")