载入库文件
from machine import Pin, SoftI2C
import network
import dht
import time
from umqtt.simple import MQTTClient
import ssd1306

# 初始化OLED
i2c = SoftI2C(scl=Pin(22), sda=Pin(21))
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# 全局变量用于持久化显示信息
temp_display_text = "Temp: -- C"
hum_display_text = "Hum: -- %"

# 连接Wi-Fi
def connect_wifi(ssid, password):
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('Connecting to network...')
        wlan.connect(ssid, password)
        while not wlan.isconnected():
            pass  # 等待连接
    print('Network connected:', wlan.ifconfig())

# MQTT订阅回调函数
def mqtt_sub_callback(topic, msg):
    global temp_display_text, hum_display_text
    print((topic, msg))
    if topic.decode() == "sensor/temperature":
        temp_display_text = "Temp: {} C".format(msg.decode())
    elif topic.decode() == "sensor/humidity":
        hum_display_text = "Hum: {} %".format(msg.decode())

    oled.fill(0)  # 清除屏幕
    oled.text(temp_display_text, 0, 0)
    oled.text(hum_display_text, 0, 16)
    oled.show()

# 设置MQTT客户端并连接到MQTT Broker
def setup_mqtt():
    mqtt_client = MQTTClient("客户端名称", "服务器地址", user="改为你的账号", password="改为你的密码", port=端口号)
    mqtt_client.set_callback(mqtt_sub_callback)
    mqtt_client.connect()
    mqtt_client.subscribe(b"sensor/temperature")
    mqtt_client.subscribe(b"sensor/humidity")
    print("Connected to MQTT Broker and subscribed to topics")
    return mqtt_client

# DHT11传感器初始化
dht_sensor = dht.DHT11(Pin(4))

# 主循环函数
def main():
    ssid = 'wifi名称'
    password = '密码'
    connect_wifi(ssid, password)
    mqtt_client = setup_mqtt()
    
    while True:
        try:
            dht_sensor.measure()
            temp = dht_sensor.temperature()
            hum = dht_sensor.humidity()
            temp_topic = "sensor/temperature"
            hum_topic = "sensor/humidity"

            mqtt_client.publish(temp_topic, str(temp))
            mqtt_client.publish(hum_topic, str(hum))

            # 检查是否有新的消息，并发布从传感器中读取的数据
            mqtt_client.check_msg()

            print('Temperature: %3.1f C' % temp)
            print('Humidity: %3.1f %%' % hum)

        except OSError as e:
            print('Failed to read sensor', e)
        
        time.sleep(2)  # 每隔两秒刷新一次数据

if __name__ == "__main__":
    main()