ESP32通过MQTT协议接入ONENET

     

一、说明

1. 基于esp-idf-v4.4.2开发；
2. 实现ESP32接入wifi；
3. 实现ESP32通过MQTT协议连接ONENET；
4. 实现ESP32订阅主题，周期性向该主题推送信息，并接收到自己推送到该主题的信息，即验证整个通信链路正常；

二、工程目录

三、程序设计

1. main.c

#include 
#include 
#include 
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_netif.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "wifi.h"
#include "mqtt.h"


static const char *TAG = "MAIN";

void app_main(void)
{
    ESP_LOGI(TAG, "[APP] Startup..");
    ESP_LOGI(TAG, "[APP] Free memory: %d bytes", esp_get_free_heap_size());
    ESP_LOGI(TAG, "[APP] IDF version: %s", esp_get_idf_version());

    esp_log_level_set("*", ESP_LOG_INFO);

    ESP_ERROR_CHECK(nvs_flash_init());//初始化nvs flash
    wifi_init();
    while(1)
    {
        vTaskDelay(pdMS_TO_TICKS(2000));
        mqtt_data_publish();
    }
}

2. wifi.c

#include "wifi.h"
#include "mqtt.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"

#define WIFI_SSID "********" // 你的WiFi名称
#define WIFI_PASS "********" // 你的WiFi密码

static const char *TAG = "WIFI";

static void wifi_event_handler(void* arg, esp_event_base_t event_base,
                               int32_t event_id, void* event_data)
{
    switch (event_id) {
        case WIFI_EVENT_STA_START:
            ESP_LOGI(TAG, "Connecting to %s", WIFI_SSID);
            esp_wifi_connect();
            break;
        case WIFI_EVENT_STA_CONNECTED:
            ESP_LOGI(TAG, "Connected to %s", WIFI_SSID);
            break;
        case WIFI_EVENT_STA_DISCONNECTED:
            ESP_LOGI(TAG, "Disconnected from %s", WIFI_SSID);
            esp_wifi_connect();
            break;
        case IP_EVENT_STA_GOT_IP:
            ESP_LOGI(TAG, "Got IP address");
            mqtt_app_init();
            break;
        default:
            break;
    }
}

void wifi_init(void)
{
    
    tcpip_adapter_init();// 初始化TCP/IP协议栈
    
    ESP_ERROR_CHECK(esp_event_loop_create_default());// 初始化WiFi事件处理程序
    
    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();// 配置WiFi连接参数
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &wifi_event_handler, NULL));// 注册WiFi事件处理程序
    ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &wifi_event_handler, NULL));
    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));// 设置WiFi工作模式为Station模式
    
    wifi_config_t wifi_config = {// 配置WiFi连接信息
        .sta = {
            .ssid = WIFI_SSID,
            .password = WIFI_PASS,
        },
    };
    
    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));// 设置WiFi连接信息
    ESP_ERROR_CHECK(esp_wifi_start());// 启动WiFi
}

3. wifi.h

#ifndef __WIFI_H
#define __WIFI_H

void wifi_init(void);

#endif

4. mqtt.c

#include "mqtt.h"
#include "mqtt_client.h"
#include "esp_log.h"

#define ESP_MQTT_HOST "183.230.40.39"
#define ESP_MQTT_URI "mqtt://mqtt.heclouds.com"
#define ESP_MQTT_PORT 6002

#define ESP_CLIENT_ID  "********"//设备id
#define ESP_PRODUCT_ID "********"//产品id
#define ESP_CLIENT_KEY "********"//API KEY

static const char *TAG = "MQTT";
esp_mqtt_client_handle_t client;

bool mqtt_connect_flag=false;

static void mqtt_event_handler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data)
{
    ESP_LOGD(TAG, "Event dispatched from event loop base=%s, event_id=%d", base, event_id);
    esp_mqtt_event_handle_t event = event_data;
    int msg_id;
    client = event->client;
    switch ((esp_mqtt_event_id_t)event_id) {
    case MQTT_EVENT_CONNECTED:
        ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
        msg_id = esp_mqtt_client_subscribe(client, "heart_report_topic", 0);
        ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
        mqtt_connect_flag=true;
        break;
    case MQTT_EVENT_DISCONNECTED:
        ESP_LOGI(TAG, "MQTT_EVENT_DISCONNECTED");
        break;

    case MQTT_EVENT_SUBSCRIBED:
        ESP_LOGI(TAG, "MQTT_EVENT_SUBSCRIBED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_UNSUBSCRIBED:
        ESP_LOGI(TAG, "MQTT_EVENT_UNSUBSCRIBED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_PUBLISHED:
            ESP_LOGI(TAG, "MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_DATA:
        ESP_LOGI(TAG, "MQTT_EVENT_DATA");
        printf("TOPIC=%.*s\r\n", event->topic_len, event->topic);
        printf("DATA=%.*s\r\n", event->data_len, event->data);
        break;
    case MQTT_EVENT_ERROR:
        ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
        if (event->error_handle->error_type == MQTT_ERROR_TYPE_TCP_TRANSPORT) {
            ESP_LOGI(TAG, "Last errno string (%s)", strerror(event->error_handle->esp_transport_sock_errno));
        }
        break;
    default:
        ESP_LOGI(TAG, "Other event id:%d", event->event_id);
        break;
    }
}

void mqtt_app_init(void)
{
    esp_mqtt_client_config_t mqtt_cfg = {
        .uri = ESP_MQTT_URI,
        .port = ESP_MQTT_PORT,
        .client_id = ESP_CLIENT_ID,//设备id
        .username = ESP_PRODUCT_ID,//产品id
        .password = ESP_CLIENT_KEY,//鉴权信息
    };
     client = esp_mqtt_client_init(&mqtt_cfg);
    esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, NULL);
    esp_mqtt_client_start(client);
}

void mqtt_data_publish(void)
{
    char data_str[50];
    int msg_id=0;

    if(mqtt_connect_flag==true)
    {
        snprintf(data_str,sizeof(data_str),"/{%s}/{%s}/heartbeat/report",ESP_PRODUCT_ID,ESP_CLIENT_ID);
        msg_id = esp_mqtt_client_publish(client, "heart_report_topic",data_str, 0, 0, 0);
        ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
    }
}

5. mqtt.h

#ifndef __MQTT_H
#define __MQTT_H

void mqtt_app_init(void);
void mqtt_data_publish(void);
#endif

      如遇到找不到头文件报错，需注意CMakeLists.txt配置。

三、成果展示

1. 通过onenet设备列表可看到设备在线状态；
   

2. 通过log可以看到ESP32成功接入onenet，实现订阅主题，周期性向该主题推送信息，并成功收到自己推送的信息，说明整个通信链路是正常的；
   

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