from machine import Pin, I2C, Timer  
import ssd1306  
import network  
import time  
import dht  
import ujson  
from umqtt.simple import MQTTClient  
  
# ESP32 Pin assignment  初始化ic2
i2c = I2C(0, scl=Pin(22), sda=Pin(21))  
#蜂鸣器初始化
buzzer_pin = Pin(2, Pin.OUT)    
  #屏幕的初始化与屏幕参数
oled_width = 128  
oled_height = 64  
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)  
  
MQTT_CLIENT_ID = "micropython-weather-demo"  
MQTT_BROKER = "broker.mqttdashboard.com"  
MQTT_USER = ""  
MQTT_PASSWORD = ""  
MQTT_TOPIC = "wokwi-weather"  
  
sensor = dht.DHT22(Pin(15))  
  #用于屏幕上读取湿度与温度
def draw_screen(temp, humidity):  
    oled.fill(0)    
    oled.text("Temp: {:.1f}°C".format(temp), 0, 0)  
    oled.text("Humidity: {:.1f}%".format(humidity), 0, 10)  
    oled.show()  
#用于蜂鸣器发出声音长度  
def beep_alarm(duration=0.5):  
    buzzer_pin.on()  
    time.sleep(duration)  
    buzzer_pin.off()  
  #用于网络连接
print("Connecting to WiFi", end="")  
sta_if = network.WLAN(network.STA_IF)  
sta_if.active(True)  
sta_if.connect('Wokwi-GUEST', '')  
#检测网络是否连接到网络接口的
while not sta_if.isconnected():  
    print(".", end="")  
    time.sleep(0.1)  
print(" Connected!")  
  #用于连接到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!")
  #设置温度报警阈值
prev_weather = ""  
threshold_temp = 30    
threshold_humidity = 80    
  #用于持续测量天气温湿度
while True:  
    print("Measuring weather conditions... ", end="")  
    sensor.measure()  
    temp = sensor.temperature()  
    humidity = sensor.humidity()
    # 触发蜂鸣器
    if temp > threshold_temp or humidity > threshold_humidity:  
        print("Alarm! Temperature or humidity exceeded threshold.")  
        beep_alarm(duration=1)   
      #将温湿度数据转化为字符串
    message = ujson.dumps({  
        "temp": temp,  
        "humidity": humidity,  
    })  
      #如果数据变化，则会更新
    if message != prev_weather:  
        print("Updated!")  
        print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))  
        client.publish(MQTT_TOPIC, message)  
        prev_weather = message  
          
         
        draw_screen(temp, humidity)  
          
          #条件语句，用于检测温度等变量是否超过阈值
        if temp > threshold_temp or humidity > threshold_humidity:  
            beep_alarm()   
    else:  
        print("No change")  
          
    time.sleep(1)