from machine import Pin, ADC, I2C
import ssd1306
import time
from umqtt.simple import MQTTClient
import ubinascii
import machine

# 网络配置（需替换为实际WiFi信息）
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = ""

# 巴法云MQTT配置
MQTT_BROKER = "bemfa.com"
MQTT_PORT = 9501
MQTT_CLIENT_ID = "7af89f740f95480fbd7c1509ae3c5d3e"
MQTT_LIGHT_TOPIC = "MQ2"

# MQ2传感器配置
MQ2_PIN = 34  # ADC复用管脚为GP34
RL_VALUE = 5  # 负载电阻值(kΩ)
RO_CLEAN_AIR_FACTOR = 9.83  # MQ2在洁净空气中的电阻比值

# OLED显示屏配置
OLED_WIDTH = 128
OLED_HEIGHT = 64
OLED_SCL = 18
OLED_SDA = 23

# 继电器和LED配置
RELAY_PIN = 15      # 继电器控制引脚
ALARM_LED_PIN = 15  # 继电器控制的LED引脚
SMOKE_THRESHOLD = 50  # 烟雾浓度低于此值时触发报警(ppm)

# 气体类型定义及对应参数
GAS_LPG = 0
GAS_CO = 1
GAS_SMOKE = 2

# 不同气体的曲线参数(a:斜率, b:截距)
GAS_PARAMS = {
    GAS_LPG: {'a': -0.45, 'b': 2.95},
    GAS_CO: {'a': -0.35, 'b': 2.30},
    GAS_SMOKE: {'a': -0.42, 'b': 3.50},
}

# 全局变量
mq2_adc = None
ro = None  # 传感器在洁净空气中的电阻值
oled = None
mqtt_client = None
relay = None
last_alarm_time = 0
alarm_interval = 1000  # 报警闪烁间隔(毫秒)

def setup_wifi():
    """连接WiFi网络"""
    import network
    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('网络配置成功, IP地址:', wlan.ifconfig()[0])

def setup_mqtt():
    """初始化MQTT客户端并连接到巴法云平台"""
    global mqtt_client
    print("正在连接到MQTT服务器...")
    mqtt_client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, MQTT_PORT)
    try:
        mqtt_client.connect()
        print("MQTT连接成功")
        return True
    except Exception as e:
        print(f"MQTT连接失败: {e}")
        return False

def setup_relay():
    """初始化继电器控制引脚"""
    global relay
    relay = Pin(RELAY_PIN, Pin.OUT)
    relay.value(0)  # 初始状态关闭继电器

def setup():
    """初始化硬件组件"""
    global mq2_adc, oled, ro
    
    # 初始化MQ2传感器
    mq2_adc = ADC(Pin(MQ2_PIN))
    mq2_adc.atten(ADC.ATTN_11DB)  # 11dB 衰减, 最大输入电压约3.6v
    
    # 初始化OLED显示屏
    i2c = I2C(0, scl=Pin(OLED_SCL), sda=Pin(OLED_SDA), freq=400000)
    oled = ssd1306.SSD1306_I2C(OLED_WIDTH, OLED_HEIGHT, i2c)
    
    # 初始化继电器
    setup_relay()
    
    # 显示初始化信息
    oled.fill(0)
    oled.text("MQ2 Sensor Init...", 0, 30)
    oled.show()
    
    # 连接WiFi
    setup_wifi()
    
    # 连接MQTT服务器
    setup_mqtt()
    
    # 传感器预热并计算Ro值
    print("MQ2传感器预热中 (需要约5秒)...")
    for i in range(5):
        print(f"预热进度: {i+1}/5秒")
        oled.fill(0)
        oled.text(f"预热中: {i+1}/5秒", 20, 30)
        oled.show()
        time.sleep(1)
    
    # 计算洁净空气中的Ro值（采样100次取平均）
    rs = 0
    for i in range(100):
        rs += calculate_rs(mq2_adc.read())
        time.sleep(0.01)
    
    ro = rs / 100 / RO_CLEAN_AIR_FACTOR
    print(f"Ro值计算完成: {ro:.2f} kΩ")
    
    # 显示系统就绪信息
    oled.fill(0)
    oled.text("MQ2 Monitor Ready", 10, 20)
    oled.text(f"Ro: {ro:.2f} kΩ", 20, 40)
    oled.show()
    time.sleep(2)

def calculate_rs(adc_value):
    """计算传感器电阻Rs"""
    if adc_value == 0:
        adc_value = 1  # 防止除零错误
    return RL_VALUE * (4095.0 / adc_value - 1)

def calculate_ppm(rs_ro_ratio, gas_type):
    """根据Rs/Ro比值和气体类型计算浓度(ppm)"""
    if gas_type not in GAS_PARAMS:
        return None
    
    a = GAS_PARAMS[gas_type]['a']
    b = GAS_PARAMS[gas_type]['b']
    
    # 使用公式: log(ppm) = a * log(Rs/Ro) + b
    return 10 ** (a * (rs_ro_ratio) + b)

def read_mq2_sensor():
    """读取MQ2传感器数据"""
    try:
        # 读取ADC值并计算Rs
        adc_value = mq2_adc.read()
        rs = calculate_rs(adc_value)
        
        # 计算Rs/Ro比值
        rs_ro_ratio = rs / ro
        
        # 计算各种气体浓度
        lpg_ppm = calculate_ppm(rs_ro_ratio, GAS_LPG)
        co_ppm = calculate_ppm(rs_ro_ratio, GAS_CO)
        smoke_ppm = calculate_ppm(rs_ro_ratio, GAS_SMOKE)
        
        return {
            'adc': adc_value,
            'rs': rs,
            'rs_ro_ratio': rs_ro_ratio,
            'lpg': lpg_ppm,
            'co': co_ppm,
            'smoke': smoke_ppm
        }
    except Exception as e:
        print(f"传感器读取错误: {e}")
        return None

def update_console(data):
    """更新控制台显示"""
    if data is None:
        print("传感器读取失败")
        return
    
    print(f"ADC值: {data['adc']}")
    print(f"Rs值: {data['rs']:.2f} kΩ")
    print(f"Rs/Ro比值: {data['rs_ro_ratio']:.2f}")
    print(f"LPG浓度: {data['lpg']:.0f} ppm")
    print(f"CO浓度: {data['co']:.0f} ppm")
    print(f"烟雾浓度: {data['smoke']:.0f} ppm")
    print("-" * 30)

def update_oled(data, alarm_active=False, alarm_msg=""):
    """更新OLED屏幕显示"""
    oled.fill(0)  # 清屏
    
    if data is None:
        oled.text("Sensor Error", 20, 30)
        oled.show()
        return
    
    # 显示标题
    oled.text("MQ2 Sensor Data", 0, 0)
    
    # 显示LPG浓度
    oled.text("LPG:", 10, 15)
    oled.text(f"{data['lpg']:.0f} ppm", 60, 15)
    
    # 显示CO浓度
    oled.text("CO:", 10, 30)
    oled.text(f"{data['co']:.0f} ppm", 60, 30)
    
    # 显示烟雾浓度
    oled.text("Smoke:", 10, 45)
    oled.text(f"{data['smoke']:.0f} ppm", 60, 45)
    
    # 显示更新时间戳
    current_time = time.localtime()
    time_str = f"{current_time[3]:02d}:{current_time[4]:02d}:{current_time[5]:02d}"
    oled.text(time_str, 90, 56)
    
    # 显示报警信息
    if alarm_active:
        oled.text("ALARM!", 0, 56)
        if alarm_msg:
            oled.text(alarm_msg, 0, 56)
    
    oled.show()  # 更新显示

def publish_to_bemfa(data, alarm_active=False, alarm_msg=""):
    """将传感器数据发布到巴法云平台"""
    if data is None or mqtt_client is None:
        return
    
    try:
        # 构建JSON格式数据
        message = f"{{\"lpg\":{data['lpg']:.0f},\"co\":{data['co']:.0f},\"smoke\":{data['smoke']:.0f}"
        
        if alarm_active:
            message += f",\"alarm\":1,\"alarm_msg\":\"{alarm_msg}\""
        else:
            message += ",\"alarm\":0"
            
        message += "}"
        
        # 发布数据到MQTT主题
        mqtt_client.publish(MQTT_LIGHT_TOPIC, message)
        print("数据已发布到巴法云平台")
    except Exception as e:
        print(f"发布到巴法云失败: {e}")
        # 尝试重新连接MQTT
        setup_mqtt()

def control_relay_alarm(active):
    """控制继电器报警LED"""
    global last_alarm_time
    
    current_time = time.ticks_ms()
    
    if active:
        # 计算时间间隔
        time_elapsed = time.ticks_diff(current_time, last_alarm_time)
        
        # 每500ms切换一次继电器状态，实现LED闪烁
        if time_elapsed >= 500:
            relay.value(not relay.value())  # 切换继电器状态
            last_alarm_time = current_time
    else:
        relay.value(0)  # 关闭继电器

def check_alarm(data):
    """检查是否需要触发警报"""
    # 设定报警阈值 (ppm)
    lpg_threshold = 2000
    co_threshold = 100
    smoke_low_threshold = SMOKE_THRESHOLD  # 烟雾浓度低于此值触发报警
    
    alarm = False
    alarm_msg = ""
    
    # 检查LPG浓度超标
    if data['lpg'] > lpg_threshold:
        alarm = True
        alarm_msg += "LPG超标! "
    
    # 检查CO浓度超标
    if data['co'] > co_threshold:
        alarm = True
        alarm_msg += "CO超标! "
    
    # 检查烟雾浓度低于阈值
    if data['smoke'] < smoke_low_threshold:
        alarm = True
        alarm_msg += f"烟雾浓度过低({data['smoke']:.0f}ppm)! "
    
    if alarm:
        print(f"警报: {alarm_msg}")
        
        # 在OLED上显示警报信息
        update_oled(data, True, alarm_msg)
        
        # 控制继电器报警LED闪烁
        control_relay_alarm(True)
        
        # 发布警报信息到巴法云
        publish_to_bemfa(data, True, alarm_msg)
        
        return True
    
    # 没有报警时关闭继电器
    control_relay_alarm(False)
    update_oled(data)
    publish_to_bemfa(data)
    
    return False

if __name__ == "__main__":
    print("启动MQ2气体监测系统...")
    
    try:
        # 初始化系统
        setup()
        
        # 主循环
        while True:
            # 读取传感器数据
            sensor_data = read_mq2_sensor()
            
            # 更新控制台显示
            update_console(sensor_data)
            
            # 检查是否需要触发警报
            check_alarm(sensor_data)
            
            # 等待1秒
            time.sleep(1)
            
    except KeyboardInterrupt:
        print("\n程序已停止")
        if oled:
            oled.fill(0)
            oled.show()  # 清屏
        if mqtt_client:
            mqtt_client.disconnect()
        if relay:
            relay.value(0)  # 确保关闭继电器
    except Exception as e:
        print(f"发生错误: {e}")
        if oled:
            oled.fill(0)
            oled.text("System Error", 20, 30)
            oled.show()
        if mqtt_client:
            mqtt_client.disconnect()
        if relay:
            relay.value(0)  # 确保关闭继电器