ESP32-C3学习笔记（7）ESP32-C3连接阿里云物联网平台并实现相互通信

1.在阿里云物联网平台建立esp32设备

创建产品与设备https://help.aliyun.com/document_detail/73705.html?spm=a2c4g.11186623.2.13.541fc5dbZseXQU

2.ESP32-C3新建工程

参考官方例程 examplesprotocolsmqtttcp

3.获取阿里云物联网平台新建的设备参数

ProductKey、DeviceName、DeviceSecret、Region、ClientID

得到如下信息

// ProductKey:"gu1apipmzjV"; 
// DeviceName:"dev-esp32c3"; 
// DeviceSecret:"4147b310a3798d203acf81b5855bb38a";
// Region:"cn-shanghai";    
// ClientID:="112233";  //自定义

4 将ESP32设备相关证书转换为程序中mqtt配置参数 

/*Broker Address��${YourProductKey}.iot-as-mqtt.${YourRegionId}.aliyuncs.com*/
#define   Aliyun_host       "gu1apipmzjV.iot-as-mqtt.cn-shanghai.aliyuncs.com"
#define   Aliyun_port       1883
/*Client ID��     ${ClientID}|securemode=${Mode},signmethod=${SignMethod}|*/
#define   Aliyun_client_id  "112233|securemode=2,signmethod=hmacsha1,timestamp=1644395422811|"
/*User Name��     ${DeviceName}&${ProductKey}*/
#define   Aliyun_username   "dev-esp32c3&gu1apipmzjV"
/*ʹ�ù��� MQTT_Password ��������*/
#define   Aliyun_password   "5920B0AC33810AA9335204A64FA1C171265C7DA0"

 5 ESP32工程主要代码

/* MQTT (over TCP) Example

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/

#include 
#include 
#include 
#include 
#include "esp_wifi.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_netif.h"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/queue.h"

#include "lwip/sockets.h"
#include "lwip/dns.h"
#include "lwip/netdb.h"

#include "esp_log.h"
#include "mqtt_client.h"
#include "os.h"

#include "user_mqtt.h"

static const char *TAG = "MQTT_EXAMPLE";

/*！！！！！！如下信息请替换成自己在阿里云的信息！！！！！！*/
/*由阿里网平台可得如下信息*/
// ProductKey:"gu1apipmzjV"; 
// DeviceName:"dev-esp32c3"; 
// DeviceSecret:"4147b310a3798d203acf81b5855bb38a";
// Region:"cn-shanghai";    


/*下面一参数为自定义*/
// ClientID:="112233";       

/*Broker Address��${YourProductKey}.iot-as-mqtt.${YourRegionId}.aliyuncs.com*/
#define   Aliyun_host       "gu1apipmzjV.iot-as-mqtt.cn-shanghai.aliyuncs.com"
#define   Aliyun_port       1883
/*Client ID��     ${ClientID}|securemode=${Mode},signmethod=${SignMethod}|*/
#define   Aliyun_client_id  "112233|securemode=2,signmethod=hmacsha1,timestamp=1644395422811|"
/*User Name��     ${DeviceName}&${ProductKey}*/
#define   Aliyun_username   "dev-esp32c3&gu1apipmzjV"
/*ʹ�ù��� MQTT_Password ��������*/
#define   Aliyun_password   "5920B0AC33810AA9335204A64FA1C171265C7DA0"

#define   AliyunSubscribeTopic_user_get     "/a1tUbQR2faQ/dev-esp32/user/get"
#define   AliyunPublishTopic_user_update    "/a1tUbQR2faQ/dev-esp32/user/update"

char mqtt_publish_data1[] = "mqtt connect ok ";
char mqtt_publish_data2[] = "mqtt subscribe successful";
char mqtt_publish_data3[] = "mqtt i am esp32";

esp_mqtt_client_handle_t client;

static esp_err_t mqtt_event_handler_cb(esp_mqtt_event_handle_t event)
{
    esp_mqtt_client_handle_t client = event->client;
    int  msg_id;
	
    // your_context_t *context = event->context;
    switch (event->event_id) {
        case MQTT_EVENT_CONNECTED:
            ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
            msg_id = esp_mqtt_client_publish(client, AliyunPublishTopic_user_update, mqtt_publish_data1, strlen(mqtt_publish_data1), 1, 0);
            ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);

            msg_id = esp_mqtt_client_subscribe(client, AliyunSubscribeTopic_user_get, 0);
            ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);

            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);
            msg_id = esp_mqtt_client_publish(client, AliyunPublishTopic_user_update, mqtt_publish_data2, strlen(mqtt_publish_data2), 0, 0);
            ESP_LOGI(TAG, "sent publish successful, msg_id=%d", 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=%.*srn", event->topic_len, event->topic);
            printf("DATA=%.*srn", event->data_len, event->data);
			
            break;
        case MQTT_EVENT_ERROR:
            ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
            break;
        default:
            ESP_LOGI(TAG, "Other event id:%d", event->event_id);
            break;
    }
    return ESP_OK;
}

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);
    mqtt_event_handler_cb(event_data);
}

static void mqtt_test_task(void *pvParameters)
{
    uint8_t num = 0;

    while(1)
    {
       esp_mqtt_client_publish(client, AliyunPublishTopic_user_update, mqtt_publish_data3, strlen(mqtt_publish_data3), 1, 0);
       vTaskDelay(2000 / portTICK_PERIOD_MS);
	   if(num++ > 5) break;
	}
    vTaskDelete(NULL);
}


void user_mqtt_app_start(void)
{
    esp_mqtt_client_config_t mqtt_cfg = {
		.host = Aliyun_host,
		.port = Aliyun_port,
		.client_id = Aliyun_client_id,
		.username = Aliyun_username,
		.password = Aliyun_password,

    };

    client = esp_mqtt_client_init(&mqtt_cfg);
    esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, client);
    esp_mqtt_client_start(client);
	
	xTaskCreate(&mqtt_test_task, "mqtt_test_task", 4096, NULL, 5, NULL);
}

6.可以在日志中查看上传的数据（UTF-8）

7.点击话题发布可以在esp32-c3串口打印中查看阿里云平台发送过来的数据