example: add example for beacon sample feature

Author: Espressif-liuuuu

examples/wifi/power_save/main/Kconfig.projbuild

@@ -145,4 +145,8 @@ menu "Example Configuration"
         default 26 if EXAMPLE_MIN_CPU_FREQ_26M
         default 13 if EXAMPLE_MIN_CPU_FREQ_13M
 
+    config EXAMPLE_POWER_SAVE_RESAMPLE
+        bool "Resample beacon when beacon loss is unstable"
+        depends on ESP_WIFI_SLP_SAMPLE_BEACON_FEATURE
+
 endmenu

examples/wifi/power_save/main/power_save.c

@@ -58,6 +58,12 @@ static void event_handler(void* arg, esp_event_base_t event_base,
     } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
         ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
         ESP_LOGI(TAG, "got ip: " IPSTR, IP2STR(&event->ip_info.ip));
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_BEACON_OFFSET_UNSTABLE) {
+        wifi_event_sta_beacon_offset_unstable_t* event = (wifi_event_sta_beacon_offset_unstable_t*)event_data;
+        ESP_LOGI(TAG, "unstable sample, beacon success rate: %.4f", event->beacon_success_rate);
+#if CONFIG_EXAMPLE_POWER_SAVE_RESAMPLE
+        esp_wifi_beacon_offset_sample_beacon();
+#endif
     }
 }