1 #define EXAMPLE_ESP_WIFI_SSID            "111"
2 #define EXAMPLE_ESP_WIFI_PASS            "19890813"
3 #define EXAMPLE_ESP_MAXIMUM_RETRY   5

需要设置的宏定义，wifi名称，wifi密码，最大尝试次数，在后续程序中会用到。

1 /* FreeRTOS event group to signal when we are connected*/
2 static EventGroupHandle_t s_wifi_event_group;//事件标志位
3 
4 /* The event group allows multiple bits for each event, but we only care about two events:
5  * - we are connected to the AP with an IP
6  * - we failed to connect after the maximum amount of retries */
7 #define WIFI_CONNECTED_BIT BIT0
8 #define WIFI_FAIL_BIT      BIT1

创建一个自定义事件标志位组，并定义我们需要的事件位。

 1 /* Waiting until either the connection is established (WIFI_CONNECTED_BIT) or connection failed for the maximum
 2      * number of re-tries (WIFI_FAIL_BIT). The bits are set by event_handler() (see above) */
 3     EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,
 4             WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
 5             pdFALSE,
 6             pdFALSE,
 7             portMAX_DELAY);
 8 
 9     /* xEventGroupWaitBits() returns the bits before the call returned, hence we can test which event actually
10      * happened. */
11     if (bits & WIFI_CONNECTED_BIT) 
12     {
13         ESP_LOGI(TAG, "connected to ap SSID:%s password:%s",
14                  EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
15     } else if (bits & WIFI_FAIL_BIT) 
16     {
17         ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s",
18                  EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
19     } else {
20         ESP_LOGE(TAG, "UNEXPECTED EVENT");
21     }

在初始化STA时，调用等待事件函数，接着判断事件标志位，判断STA是否连接成功。

 1

    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
 2                                                         ESP_EVENT_ANY_ID,
 3                                                         &event_handler,
 4                                                         NULL,
 5                                                         &instance_any_id));
 6 ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,
 7                                                         IP_EVENT_STA_GOT_IP,
 8                                                         &event_handler,
 9                                                         NULL,
10                                                         &instance_got_ip));

这里是给特定的系统事件来绑定到event_handler,接着就可以在event_handle中写我们的事件处理函数，在中断中判断事件类型和id可以判断出具体的事件类型，

1     ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );
2     ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config) );
3     ESP_ERROR_CHECK(esp_wifi_start() );

STA配置完成后，调用这三个函数，就可以启动STA。

1     /* The event will not be processed after unregister */
2     ESP_ERROR_CHECK(esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, instance_got_ip));
3     ESP_ERROR_CHECK(esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id));
4     vEventGroupDelete(s_wifi_event_group);

当系统事件和自定义事件已经用完，需要将内存释放，事件解绑。