W55MH32使用MQTT协议连接阿里云

本篇总结

本例程在 W55MH32 上通过 MQTT 协议接入阿里云物联网平台，实现温湿度数据上报与属性设置主题的订阅。

硬件平台：本例程基于 W55MH32L-EVB 开发板运行。

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阿里云物联网平台简介

阿里云物联网平台提供设备接入、设备管理、数据订阅和规则引擎等能力。本例程使用一机一密认证方式，设备需要预置 ProductKey、DeviceName、DeviceSecret 三个凭证。连接时根据阿里云规则生成 ClientId、Username、Password（HMAC-SHA256 签名）。接入域名格式为 {instanceId}.mqtt.iothub.aliyuncs.com:1883（企业版实例）。

void TIM3_IRQHandler(void)
{
    static uint32_t tim3_1ms_count = 0;
    if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
    {
        tim3_1ms_count++;
        MilliTimer_Handler();

        if (tim3_1ms_count >= 1000)
        {
            DHCP_time_handler();
            DNS_time_handler();
            tim3_1ms_count = 0;
        }

        TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
    }
}

mqttconn mqtt_params = {
    .mqttHostUrl = "iot-06z00dbroeg8dx3.mqtt.iothub.aliyuncs.com",
    .server_ip   = {0},
    .port        = 1883,
    .clientid    = "ieojgBm5q2c.W55MH32|securemode=2,signmethod=hmacsha256,timestamp=1737098648080|",
    .username    = "W55MH32&XXXXXXXXXXX",
    .passwd      = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
    .pubtopic    = "/sys/iXXXXXXXXXXX/W55MH32/thing/event/property/post",
    .subtopic    = "/sys/iXXXXXXXXXXX/W55MH32/thing/service/property/set",
    .pubQoS      = QOS0,
};

如果你想自定义

• mqttHostUrl → 接入域名格式：{instanceId}.mqtt.iothub.aliyuncs.com（企业版实例）或 {ProductKey}.iot-as-mqtt.{RegionId}.aliyuncs.com（公共实例）
• clientid → 格式：{instanceId}.{DeviceName}|securemode=2,signmethod=hmacsha256,timestamp={timestamp}|，securemode=2 为 TCP 直连
• username → 格式：{DeviceName}&{instanceId}
• passwd → 由 DeviceSecret 对拼接字符串进行 HMAC-SHA256 签名生成
• pubtopic → 属性上报：/sys/{instanceId}/{DeviceName}/thing/event/property/post
• subtopic → 属性设置：/sys/{instanceId}/{DeviceName}/thing/service/property/set

void mqtt_init(uint8_t sn, uint8_t *send_buf, uint8_t *recv_buf)
{
    wiz_NetInfo get_info = {0};
    wizchip_getnetinfo(&get_info);

    /* DNS 解析阿里云接入域名 */
    if (do_dns(send_buf, (uint8_t *)mqtt_params.mqttHostUrl, mqtt_params.server_ip))
    {
        while (1);
    }

    NewNetwork(&n, sn);
    ConnectNetwork(&n, mqtt_params.server_ip, mqtt_params.port);
    MQTTClientInit(&c, &n, 1000, send_buf, MQTT_ETHERNET_MAX_SIZE, recv_buf, MQTT_ETHERNET_MAX_SIZE);

    /* MQTT 连接参数 */
    data.MQTTVersion       = 4;
    data.clientID.cstring  = mqtt_params.clientid;
    data.username.cstring  = mqtt_params.username;
    data.password.cstring  = mqtt_params.passwd;
    data.keepAliveInterval = 30;
    data.cleansession      = 1;
}

void do_mqtt(void)
{
    uint8_t ret;
    switch (run_status)
    {
    case CONN:
    {
        ret = MQTTConnect(&c, &data);
        printf("Connect to the MQTT server: %d.%d.%d.%d:%d\r\n",
               mqtt_params.server_ip[0], mqtt_params.server_ip[1],
               mqtt_params.server_ip[2], mqtt_params.server_ip[3],
               mqtt_params.port);
        printf("Connected:%s\r\n\r\n", ret == SUCCESSS ? "success" : "failed");
        if (ret != SUCCESSS)
        {
            run_status = ERR;
        }
        else
        {
            run_status = SUB;
        }
        break;
    }
    case SUB:
    {
        ret = MQTTSubscribe(&c, mqtt_params.subtopic, mqtt_params.subQoS, messageArrived);
        printf("Subscribing to %s\r\n", mqtt_params.subtopic);
        printf("Subscribed:%s\r\n\r\n", ret == SUCCESSS ? "success" : "failed");
        if (ret != SUCCESSS)
        {
            run_status = ERR;
        }
        else
        {
            run_status = PUB_MESSAGE;
        }
        break;
    }
    case PUB_MESSAGE:
    {
        pubmessage.qos = QOS0;
        pubmessage.payload = "{\"id\":\"123\",\"version\":\"1.0\",\"params\":{\"CurrentTemperature\":26.6,},\"method\":\"thing.event.property.post\"}";
        pubmessage.payloadlen = strlen(pubmessage.payload);
        ret = MQTTPublish(&c, (char *)&(mqtt_params.pubtopic), &pubmessage);
        if (ret != SUCCESSS)
        {
            run_status = ERR;
        }
        else
        {
            printf("publish:%s,%s\r\n\r\n", mqtt_params.pubtopic, (char *)pubmessage.payload);
            run_status = KEEPALIVE;
        }
        break;
    }
    case KEEPALIVE:
    {
        if (MQTTYield(&c, 30) != SUCCESSS)
        {
            run_status = ERR;
        }
    }
    case RECV:
    {
        if (mqtt_recv_flag)
        {
            mqtt_recv_flag = 0;
            json_decode(mqtt_recv_msg);
        }
        break;
    }
    case ERR:
        printf("system ERROR!");
        delay_ms(1000);
        break;
    default:
        break;
    }
}

void messageArrived(MessageData *md)
{
    char topicname[64] = {0};
    char msg[512] = {0};

    sprintf(topicname, "%.*s", (int)md->topicName->lenstring.len, md->topicName->lenstring.data);
    sprintf(msg, "%.*s", (int)md->message->payloadlen, (char *)md->message->payload);
    printf("recv:%s,%s\r\n\r\n", topicname, msg);

    mqtt_recv_flag = 1;
    memset(mqtt_recv_msg, 0, sizeof(mqtt_recv_msg));
    memcpy(mqtt_recv_msg, msg, strlen(msg));
}

void json_decode(char *msg)
{
    cJSON *jsondata = NULL;
    cJSON *params = NULL;
    cJSON *LED = NULL;

    jsondata = cJSON_Parse(msg);
    if (jsondata == NULL)
    {
        printf("json parse fail.\r\n");
        return;
    }

    params = cJSON_GetObjectItem(jsondata, "params");
    LED = cJSON_GetObjectItem(params, "LEDSwitch");

    if (LED->valueint == 1)
    {
        printf("LED ON\r\n");
    }
    else
    {
        printf("LED OFF\r\n");
    }

    cJSON_Delete(jsondata);
}

JSON 解析说明

json_decode() 使用 cJSON 库解析阿里云下发的 JSON，从 params 中提取 LEDSwitch 字段，打印对应状态。阿里云下发的属性设置指令格式为 {"params":{"LEDSwitch":1}}。