"""
MicroPython IoT Weather Station Example for Wokwi.com

To view the data:

1. Go to http://www.hivemq.com/demos/websocket-client/
2. Click "Connect"
3. Under Subscriptions, click "Add New Topic Subscription"
4. In the Topic field, type "wokwi-weather" then click "Subscribe"

Now click on the DHT22 sensor in the simulation,
change the temperature/humidity, and you should see
the message appear on the MQTT Broker, in the "Messages" pane.

Copyright (C) 2022, Uri Shaked

https://wokwi.com/arduino/projects/322577683855704658
"""
# 导入必要的库  
import network
import time
from machine import Pin
import dht
import ujson
from umqtt.simple import MQTTClient
from machine import Pin, I2C
import ssd1306


# MQTT服务器参数 
MQTT_CLIENT_ID = "micropython-weather-demo"
MQTT_BROKER    = "broker.mqttdashboard.com"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC     = "wokwi-weather"

# 初始化DHT22传感器  
sensor = dht.DHT22(Pin(15))

# ESP32 I2C配置  
i2c = I2C(0, scl=Pin(22), sda=Pin(21))

# 蜂鸣器和LED引脚配置  
buzzer_pin = Pin(27,Pin.OUT)#蜂鸣器连接到GPIO27
led_pin =Pin(0,Pin.OUT)#LED连接到GPIO0
led_pin.off()  #初始时关闭led

#设定温度报警阈值
A=TEMP_THRESHOLD_HIGH=30.0    #最高温度阈值
B=TEMP_THRESHOLD_LOW=15.0    #最低为温度阈值
C=HUMIDITY_THRESHOLD_HIGH=80.0    #最高湿度阈值
D=HUMIDITY_THRESHOLD_LOW=30.0    #最低湿度阈值

# OLED显示屏配置
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

# 连接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!")

# 连接MQTT服务器 
print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.connect()
print("Connected!")

#初始化
prev_weather = ""
#这是一个无限循环，它将一直运行，直到外部中断或程序被强制停止。
while True:
  print("Measuring weather conditions... ", end="")
  sensor.measure()   #调用sensor.measure()方法来获取最新的温度和湿度值。
  temp = sensor.temperature()
  humidity = sensor.humidity()   #测量温度和湿度

  if(temp >=A or temp<=B) or (humidity >= C or humidity <=D):  # 条件判断
    buzzer_pin.on() #蜂鸣报警
    time.sleep(1)
    led_pin.on()
    time.sleep(2)  # 蜂鸣器和LED保持2秒 
    buzzer_pin.off()#关闭蜂鸣器

  #构建和发送MQTT消息,将当前的温度和湿度值打包成一个JSON字符串，
  #并使用ujson.dumps()方法将其转换为JSON格式。
  #然后，它检查这个新的消息是否与上一次发送的消息不同。
  #如果不同，它将发送新的MQTT消息，并更新prev_weather变量。
  message = ujson.dumps({
    "temp": temp,
    "humidity": humidity,
  })
  if message != prev_weather:
    print("Updated!")
    print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))
    try:
      client.publish(MQTT_TOPIC, message)
    except Exception as e:
      print("MQTT publish failed:",e)   #if...发送MQTT消息的代码
    prev_weather = message
    #OLED显示
    oled.fill(0)    # 清除屏幕    
    oled.text('temp:{:.1f}'.format(temp),10,10)
    oled.text('humidity:{:.1f}'.format(humidity),0,0)
    oled.show()  #如果消息有更新，程序会在OLED屏幕上显示当前的温度和湿度
  else:
     print("No change")
  time.sleep(1)    # 等待一段时间再次测量