import network
import time
from machine import Pin, I2C
import ujson
from umqtt.robust import MQTTClient

# Ubidots Token and Client ID
ubidotsToken = "BBUS-4e6v24O4dEhy3NeTzSnMJ5WASGcOUQ"
clientID = "dandebharath03"

# SI7021 I2C address and commands
SI7021_ADDR = 0x40
HUMIDITY_CMD = 0xF5
TEMPERATURE_CMD = 0xF3

# Initialize I2C
i2c = I2C(0, scl=Pin(22), sda=Pin(21))  # I2C(0) with pins SCL=22, SDA=21

# Connect to WiFi
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')
while not sta_if.isconnected():
    print(".", end="")
    time.sleep(0.1)
print(" Connected!")

# Connect to MQTT server
print("Connecting to MQTT server... ", end="")
client = MQTTClient(clientID, "industrial.api.ubidots.com", 1883, user=ubidotsToken, password=ubidotsToken)
client.connect()
print("Connected!")

# Function to read humidity from SI7021
def readHumidity():
    i2c.writeto(SI7021_ADDR, bytearray([HUMIDITY_CMD]))  # Send humidity measurement command
    time.sleep(0.5)  # Wait for measurement to complete
    data = i2c.readfrom(SI7021_ADDR, 2)  # Read 2 bytes of data
    msb, lsb = data[0], data[1]
    humidity = ((msb << 8) | lsb) * 125.0 / 65536.0 - 6.0
    return humidity

# Function to read temperature from SI7021 in Celsius
def readTemperature():
    i2c.writeto(SI7021_ADDR, bytearray([TEMPERATURE_CMD]))  # Send temperature measurement command
    time.sleep(0.5)  # Wait for measurement to complete
    data = i2c.readfrom(SI7021_ADDR, 2)  # Read 2 bytes of data
    msb, lsb = data[0], data[1]
    temperature = ((msb << 8) | lsb) * 175.72 / 65536.0 - 46.85
    return temperature

# Loop to send data every 1 second
prev_weather = ""
while True:
    print("Measuring weather conditions... ", end="")
    
    # Read humidity and temperature
    humidity = readHumidity()
    temperature = readTemperature()

    # Prepare message to send
    message = ujson.dumps({
        "temperature": temperature,
        "humidity": humidity,
    })
    
    # Only publish the message if it has changed
    if message != prev_weather:
        print("Updated!")
        client.publish(b"/v1.6/devices/ESP32", message)
        prev_weather = message
    else:
        print("No change")
    
    # Sleep for 1 second before the next measurement
    time.sleep(1)