from machine import Pin, ADC
from time import sleep
import network
from umqtt.simple import MQTTClient

# 巴法云平台配置
SERVER = "bemfa.com"
PORT = 9501
PRIVATE_KEY = "3e74bc9a643481be57b70de123a7e419"  # 私钥
TOPIC = "MQ2"  # 主题名

# WiFi 配置
WIFI_SSID = "Wokwi-GUEST" 
WIFI_PASSWORD = ""

# 传感器配置
gas_pin = 34
gas_ADC = ADC(Pin(gas_pin))
gas_ADC.atten(ADC.ATTN_11DB)  # 11dB 衰减，最大输入电压约 3.6V

# WiFi连接函数
def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('正在连接WiFi...')
        wlan.connect(WIFI_SSID, WIFI_PASSWORD)
        while not wlan.isconnected():
            pass
    print('WiFi连接成功，网络配置:', wlan.ifconfig())

def sub_callback(topic, msg):
    print('收到来自主题 %s 的消息: %s' % (topic, msg))

# 初始化MQTT客户端
def init_mqtt():
    client = MQTTClient(PRIVATE_KEY, SERVER, PORT)
    client.set_callback(sub_callback)
    try:
        client.connect()
        client.subscribe(TOPIC.encode())
        print(f'已连接到MQTT服务器 {SERVER}，订阅主题: {TOPIC}')
        return client
    except Exception as e:
        print(f'MQTT连接失败: {e}')
        return None

# 主程序
def main():
    connect_wifi()
    mqtt_client = init_mqtt()
    
    if mqtt_client is None:
        print('MQTT连接失败，使用HTTP上传数据')
    
    while True:
        # 读取传感器
        gas_value = gas_ADC.read()
        print(f'传感器值: {gas_value}')
        
        # 发布数据到MQTT
        if mqtt_client:
            try:
                mqtt_client.publish(TOPIC.encode(), str(gas_value).encode())
                mqtt_client.check_msg()  # 检查订阅消息
            except Exception as e:
                print(f'MQTT发布失败: {e}')
                mqtt_client = init_mqtt()  
        
        sleep(2)  # 每2秒上传一次

if __name__ == '__main__':
    main()