MQTTS连接adafruit平台示例

本篇总结

本例程在 W55MH32 上通过 MQTTS（MQTT over SSL/TLS）协议接入 Adafruit IO 物联网平台，实现温湿度数据的周期发布与 LED/BEEP 主题的订阅控制。

硬件平台：本例程基于 W55MH32L-EVB 开发板运行。

采购推荐：点击前往 WIZnet 官方淘宝店铺 选购 W55MH32L-EVB

W55MH32 的 TLS 支持

W55MH32 集成了硬件加密引擎（AES、SHA、TRNG），SDK 基于硬件加密引擎移植了 mbedTLS 库，提供完整的 TLS 握手与加解密能力。通过 wiz_tls_init() 和 wiz_tls_connect() 即可建立安全连接。MQTTS 使用端口 8883（普通 MQTT 使用 1883）。

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 = "io.adafruit.com",
    .server_ip   = {0},
#ifdef MQTTS
    .port = 8883,          /* MQTTS 使用 8883 端口 */
#else
    .port = 1883,          /* 普通 MQTT 使用 1883 端口 */
#endif
    .clientid   = "Mr_huang1220_adafruit_io_connection",
    .username   = "Mr_huang1220",
    .passwd     = "aio_BiYJ23jjamijB8bx6lS2x8o5uVWi",
    .pubtopic   = "Mr_huang1220/groups/w55mh32-evb",
    .subtopic   = "Mr_huang1220/groups/w55mh32-evb",
    .pubQoS     = QOS0,
};

如果你想自定义

• 端口说明 → MQTTS 使用 8883（SSL/TLS 加密），普通 MQTT 使用 1883。通过宏定义 MQTTS 切换两种模式
• Topic 命名规则 → Adafruit IO 的 Groups 格式为 用户名/groups/组名。本例程发布与订阅使用同一个主题，通过 JSON 中的 feeds 字段区分数据来源
• AIO Key 获取 → 登录 Adafruit IO 后，点击右上角头像进入 "View AIO Key" 页面

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 Adafruit IO 域名 */
    if (do_dns(send_buf, (uint8_t *)mqtt_params.mqttHostUrl, mqtt_params.server_ip))
    {
        while (1);
    }

#ifdef MQTTS
    /* TLS 初始化 */
    wiz_tls_socket(&tlsContext, sn, mqtt_params.local_port);
    wiz_tls_init(&tlsContext, 2000, (char *)mqtt_params.server_ip, NULL, NULL, NULL);

    NewNetwork(&n, sn);
    n.mqttread   = tls_mqtt_read;      /* 收发函数替换为 TLS 版本 */
    n.mqttwrite  = tls_mqtt_write;
    n.disconnect = tls_mqtt_disconnect;

    /* TCP 连接 + TLS 握手 */
    connect(tlsContext.socket_fd, (uint8_t *)mqtt_params.server_ip, mqtt_params.port);
    wiz_tls_connect(&tlsContext, (char *)mqtt_params.server_ip, mqtt_params.port);

    mbedtls_ssl_conf_read_timeout(tlsContext.conf, 2000);
    MQTTClientInit(&c, &n, 2000, send_buf, MQTT_ETHERNET_MAX_SIZE, recv_buf, MQTT_ETHERNET_MAX_SIZE);

#else
    /* 普通 MQTT 模式 */
    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);
#endif

    /* 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: {
        if (mqtt_send_flag)
        {
            mqtt_send_flag = 0;
            pubmessage.qos = QOS0;

            /* 拼装 JSON 数据：LED / BEEP 状态 + AHT20 温湿度 */
            sprintf(pubmessage.payload,
                    "{\"feeds\":{\"led\":%d,\"beep\":%d,\"humidity\":%.2f,\"temperature\":%.2f}}",
                    GPIO_ReadOutputDataBit(LED_PORT, LED_PIN),
                    GPIO_ReadOutputDataBit(BEEP_PORT, BEEP_PIN),
                    SENx.RH, SENx.T);
            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);
        }
    }
    /* no break — 继续执行 KEEPALIVE */

    case KEEPALIVE: {
        if (MQTTYield(&c, 30) != SUCCESSS) run_status = ERR;
    }
    /* no break — 继续执行 RECV */

    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;
    }
}

发布数据格式

设备通过 feeds 字段同时上报 LED 状态、BEEP 状态、湿度和温度。Adafruit IO 收到后会自动分发到对应 Feed 记录，例如 {"feeds":{"led":1,"beep":0,"humidity":37.12,"temperature":32.53}}。

void messageArrived(MessageData *md)
{
    static char topicname[64] = {0};
    static 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 *feeds    = NULL;
    cJSON *led      = NULL;
    cJSON *beep     = NULL;

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

    feeds = cJSON_GetObjectItem(jsondata, "feeds");
    if (feeds == NULL) { printf("params parse fail.\r\n"); return; }

    /* LED 控制：0 点亮，非 0 熄灭（板载 LED 低电平点亮） */
    led = cJSON_GetObjectItem(feeds, "led");
    if (led != NULL)
    {
        if (atoi(led->valuestring) == 0)
        {
            GPIO_ResetBits(LED_PORT, LED_PIN);
            printf("LED ON\r\n");
        }
        else
        {
            GPIO_SetBits(LED_PORT, LED_PIN);
            printf("LED OFF\r\n");
        }
    }

    /* BEEP 控制：1 鸣叫，0 停止 */
    beep = cJSON_GetObjectItem(feeds, "beep");
    if (beep != NULL)
    {
        if (atoi(beep->valuestring) == 1)
        {
            GPIO_SetBits(BEEP_PORT, BEEP_PIN);
            printf("BEEP ON\r\n");
        }
        else
        {
            GPIO_ResetBits(BEEP_PORT, BEEP_PIN);
            printf("BEEP OFF\r\n");
        }
    }

    cJSON_Delete(jsondata);
}

JSON 解析说明

json_decode() 使用 cJSON 库解析 Adafruit IO 下发的 JSON，从 feeds 中提取 led / beep 字段。板载 LED 为低电平点亮，所以 led = 0 点亮、led = 1 熄灭。BEEP 相反，beep = 1 鸣叫、beep = 0 停止。