import network          # For Wi-Fi connectivity
import time             # For delays and timing
import urequests        # For making HTTP requests
import dht              # For interfacing with DHT sensors
from machine import Pin # For controlling GPIO pins

ssid = 'Wokwi-GUEST'    # SSID of the Wi-Fi network
password = ''           # Password (empty for open networks like Wokwi-GUEST)

THINGSPEAK_API_KEY = 'P95S82N65IHD2859' # Your ThingSpeak Write API key
THINGSPEAK_URL = 'https://api.thingspeak.com/update' # ThingSpeak endpoint

wlan = network.WLAN(network.STA_IF) # Create a WLAN object in station mode,
                                    # the device connetcs to a Wi-Fi network as a client.
                                    # Other option: AP_IF, Acces Point mode -
                                    # the device creates its own Wi-Fi network (hotspot).
wlan.active(True)                   # Activate the Wi-Fi interface
wlan.connect(ssid, password)        # Connect to the specified Wi-Fi network

print("Connecting to Wi-Fi...", end="")
while not wlan.isconnected():
    print(".", end="")              # Print dots while waiting
    time.sleep(0.5)                 # Wait 0.5 seconds before retrying

# Once connected, print confirmation and IP address
print("\nConnected!")
print("IP address:", wlan.ifconfig()[0])

# Initialize the DTH22 sensor on GPIO pin 15
sensor = dht.DHT22(Pin(15))

# Function to send temperature data to ThingSpeak
def send_to_thingspeak(temp):
    if temp is None:
        print("Nothing to send")
        return
    try:
        # Send HTTP POST request to ThingSpeak with temperature data
        response = urequests.post(
            THINGSPEAK_URL,
            data = 'api_key={}&field1={}'.format(THINGSPEAK_API_KEY, temp),
            headers={'Content-Type': 'application/x-www-form-urlencoded'}
        )
        print("ThingSpeak response:", response.text)            # Print server response
        response.close()                                        # Close the connection
    except Exception as e:
        print("Failed sending data:", e)                        # Handle any errors

# Main loop: read sensor and send data every 15 seconds
while True:
    try:
        sensor.measure()                                        # Trigger sensor measurement
        temperature = sensor.temperature()                      # Read temperature in Celcius
        print("Temperature:", temperature, "°C")                # Display temperature
        send_to_thingspeak(temperature)
    except Exception as e:
        print("Error reading sensor or sending data:", e)       # Handle errors
    
    time.sleep(15)                                              # Wait 15 seconds before next reading