1. 订阅和发布 topic
设备消息相关Topic
| $oc/devices/{device_id}/sys/messages/up | 设备消息上报 |
|---|---|
| $oc/devices/{device_id}/sys/messages/down | 平台下发消息给设备 |
更多 Topic 参看 华为云Topic定义
2.三元组信息转换网址
3. MQTT TCP示例
/* 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 <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include "esp_wifi.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_netif.h"
#include "protocol_examples_common.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"
static const char *TAG = "MQTT_EXAMPLE";
static void log_error_if_nonzero(const char *message, int error_code)
{
if (error_code != 0) {
ESP_LOGE(TAG, "Last error %s: 0x%x", message, error_code);
}
}
/*
* @brief Event handler registered to receive MQTT events
*
* This function is called by the MQTT client event loop.
*
* @param handler_args user data registered to the event.
* @param base Event base for the handler(always MQTT Base in this example).
* @param event_id The id for the received event.
* @param event_data The data for the event, esp_mqtt_event_handle_t.
*/
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;
esp_mqtt_client_handle_t client = event->client;
int msg_id;
switch ((esp_mqtt_event_id_t)event_id) {
case MQTT_EVENT_CONNECTED:
ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
msg_id = esp_mqtt_client_publish(client, " $oc/devices/6414372a_mqtt_test/sys/messages/up", "data_3", 0, 1, 0);
ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
msg_id = esp_mqtt_client_subscribe(client, "$oc/devices/641437241f9dong_mqtt_test/sys/messages/down", 0);
ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
// msg_id = esp_mqtt_client_subscribe(client, "/topic/qos1", 1);
// ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
// msg_id = esp_mqtt_client_unsubscribe(client, "/topic/qos1");
// ESP_LOGI(TAG, "sent unsubscribe 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, " $oc/devices/6414372a4077374_mqtt_test/sys/messages/up", "data_3", 0, 1, 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=%.*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) {
log_error_if_nonzero("reported from esp-tls", event->error_handle->esp_tls_last_esp_err);
log_error_if_nonzero("reported from tls stack", event->error_handle->esp_tls_stack_err);
log_error_if_nonzero("captured as transport's socket errno", event->error_handle->esp_transport_sock_errno);
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;
}
}
static void mqtt_app_start(void)
{
esp_mqtt_client_config_t mqtt_cfg = {
.broker.address.uri = "mqtt://2b2f8c1c14eicloud.com:1883",
.credentials.username = "6414372a40773741f9g_mqtt_test",
.credentials.client_id = "6414372a40773741f9fb9b01_jist_0_0_2023032212",
.credentials.authentication.password = "628b2d6376fd7f1640cfbbfdf0094dc5fa980963c7d17fdfdd53ef"
};
#if CONFIG_BROKER_URL_FROM_STDIN
char line[128];
if (strcmp(mqtt_cfg.broker.address.uri, "FROM_STDIN") == 0) {
int count = 0;
printf("Please enter url of mqtt broker\n");
while (count < 128) {
int c = fgetc(stdin);
if (c == '\n') {
line[count] = '\0';
break;
} else if (c > 0 && c < 127) {
line[count] = c;
++count;
}
vTaskDelay(10 / portTICK_PERIOD_MS);
}
mqtt_cfg.broker.address.uri = line;
printf("Broker url: %s\n", line);
} else {
ESP_LOGE(TAG, "Configuration mismatch: wrong broker url");
abort();
}
#endif /* CONFIG_BROKER_URL_FROM_STDIN */
esp_mqtt_client_handle_t client = esp_mqtt_client_init(&mqtt_cfg);
/* The last argument may be used to pass data to the event handler, in this example mqtt_event_handler */
esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, NULL);
esp_mqtt_client_start(client);
}
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_log_level_set("mqtt_client", ESP_LOG_VERBOSE);
esp_log_level_set("MQTT_EXAMPLE", ESP_LOG_VERBOSE);
esp_log_level_set("TRANSPORT_BASE", ESP_LOG_VERBOSE);
esp_log_level_set("esp-tls", ESP_LOG_VERBOSE);
esp_log_level_set("TRANSPORT", ESP_LOG_VERBOSE);
esp_log_level_set("outbox", ESP_LOG_VERBOSE);
ESP_ERROR_CHECK(nvs_flash_init());
ESP_ERROR_CHECK(esp_netif_init());
ESP_ERROR_CHECK(esp_event_loop_create_default());
/* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
* Read "Establishing Wi-Fi or Ethernet Connection" section in
* examples/protocols/README.md for more information about this function.
*/
ESP_ERROR_CHECK(example_connect());
mqtt_app_start();
}