W6300使用MQTT协议连接OneNET

本篇总结

本例程在 W6300 上通过 MQTT 协议接入中移物联网 OneNET 平台，实现属性数据上报与 LED 主题的订阅控制。

硬件平台：本例程基于 W6300-EVB-M4 开发板运行。

采购推荐：点击前往 WIZnet 官方淘宝店铺 选购 W6300-EVB-M4 开发板

OneNET 平台简介

OneNET 是中移物联网有限公司打造的 PaaS 物联网平台，支持 MQTT、HTTP、LwM2M 等多种协议接入。本例程使用 OneNET MQTT 接入方式（mqtts.heclouds.com:1883），采用 token 鉴权。设备通过发布属性主题上报遥测数据，通过订阅属性设置主题接收云端控制指令，并向回复主题发送确认响应。

/* register MQTT MilliTimer handler */
wiz_add_timer(MilliTimer_Handler, 1);

mqttconn mqtt_params = {
    .mqttHostUrl = "mqtts.heclouds.com",
    .server_ip = {0},
    .port = 1883,
    .clientid = "W6300",
    .username = "14g5eK3W52",
    .passwd = "version=2018-10-31&res=products%2F14g5eK3W52%2Fdevices%2FW6300&et=1792723202&method=md5&sign=OMogJA2DOPS7hdwEXWjVoA%3D%3D",
    .pubtopic = "$sys/14g5eK3W52/W6300/thing/property/post",
    .pubtopic_reply = "$sys/14g5eK3W52/W6300/thing/property/post/reply",
    .subtopic = "$sys/14g5eK3W52/W6300/thing/property/set",
    .subtopic_reply = "$sys/14g5eK3W52/W6300/thing/property/set_reply",
    .pubQoS = QOS0,
    .willtopic = "/wizchip/will",
    .willQoS = QOS0,
    .willmsg = "wizchip offline!",
    .subQoS = QOS0,
};

如果你想自定义

• clientid/username → 填写设备的 device_id（设备 ID）
• passwd → OneNET token，格式为 version&res&et&method&sign，sign 由 access_key 通过 HMAC 生成
• pubtopic → OneNET 物模型的属性上报主题：$sys/{pid}/{device_id}/thing/property/post
• subtopic → OneNET 物模型的属性设置主题：$sys/{pid}/{device_id}/thing/property/set

void mqtt_init(uint8_t sn, uint8_t *send_buf, uint8_t *recv_buf)
{
    /* DNS parsing */
    if (do_dns(send_buf, (uint8_t *)mqtt_params.mqttHostUrl, mqtt_params.server_ip))
    {
        if (mqtt_params.server_ip[0] != 0)
        {
            printf("Use Default Server Internet Protocol Address:%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]);
        }
        else
        {
            printf("No default server address, unable to connect to the server\r\n");
            while (1) { }
        }
    }

    /* register MQTT MilliTimer handler */
    wiz_add_timer(MilliTimer_Handler, 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);

    willdata.qos = mqtt_params.willQoS;
    willdata.topicName.lenstring.data = mqtt_params.willtopic;
    willdata.topicName.lenstring.len = strlen(willdata.topicName.lenstring.data);
    willdata.message.lenstring.data = mqtt_params.willmsg;
    willdata.message.lenstring.len = strlen(willdata.message.lenstring.data);
    willdata.retained = 0;
    willdata.struct_version = 3;

    data.willFlag = 0;
    data.will = willdata;
    data.MQTTVersion = 4;
    data.clientID.cstring = mqtt_params.clientid;
    data.username.cstring = mqtt_params.username;
    data.password.cstring = mqtt_params.passwd;
    data.keepAliveInterval = MQTT_ONENET_KEEPALIVE_S;
    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");
        run_status = (ret != SUCCESSS) ? ERR : 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; break; }

        ret = MQTTSubscribe(&c, mqtt_params.pubtopic_reply, mqtt_params.subQoS, messageArrived);
        printf("Subscribing to %s\r\n", mqtt_params.pubtopic_reply);
        printf("Subscribed:%s\r\n\r\n", ret == SUCCESSS ? "success" : "failed");
        run_status = (ret != SUCCESSS) ? ERR : PUB_MESSAGE;
        break;
    }

    case PUB_MESSAGE:
    {
        pubmessage.qos = QOS0;
        pubmessage.payload = "{\"id\":\"123\",\"version\":\"1.0\",\"params\":{\"CurrentTemperature\":{\"value\":26.6}}}";
        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;
        }
        wiz_user_delay_ms(100);
    }
    /* no break */

    case RECV:
    {
        if (mqtt_recv_flag)
        {
            mqtt_recv_flag = 0;
            json_decode(mqtt_recv_msg);
        }
        wiz_user_delay_ms(100);
        break;
    }

    case ERR:
        printf("system ERROR!");
        wiz_user_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);

    if (strcmp(topicname, mqtt_params.subtopic) == 0)
    {
        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)
{
    int ret;
    char replymsg[128] = {0};
    cJSON *id = NULL;
    cJSON *jsondata = NULL;
    cJSON *params = NULL;
    cJSON *LED = NULL;

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

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

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

    pubmessage.qos = QOS0;
    sprintf(replymsg, "{\"id\":\"%s\",\"code\":200,\"msg\":\"success\"}", id->valuestring);
    printf("reply:%s\r\n", replymsg);

    pubmessage.payload = replymsg;
    pubmessage.payloadlen = strlen(replymsg);
    ret = MQTTPublish(&c, mqtt_params.subtopic_reply, &pubmessage);
    if (ret != SUCCESSS)
    {
        run_status = ERR;
    }
    else
    {
        printf("publish:%s,%s\r\n\r\n", mqtt_params.subtopic_reply, (char *)pubmessage.payload);
    }

    cJSON_Delete(jsondata);
}

JSON 解析说明

json_decode() 使用 cJSON 库解析 OneNET 下发的 JSON 指令，字段路径为 params.LEDSwitch。OneNET 下发的指令格式为 {"id":"1","version":"1.0","params":{"LED":1}}。收到 1 时打印 LED ON，收到 0 时打印 LED OFF，随后向 set_reply 主题发送成功响应。