fix(ble/bluedroid): Optimized BLE SPP example for improved compatibility

examples/bluetooth/bluedroid/ble/ble_spp_server/main/ble_spp_server_demo.c

@@ -1,10 +1,8 @@
 /*
-   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.
-*/
+ * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
 
 
 #include "freertos/FreeRTOS.h"
@@ -22,6 +20,7 @@
 #include "esp_bt_defs.h"
 #include "esp_bt_main.h"
 #include "ble_spp_server_demo.h"
+#include "esp_gatt_common_api.h"
 
 #define GATTS_TABLE_TAG  "GATTS_SPP_DEMO"
 
@@ -320,7 +319,7 @@ void uart_task(void *pvParameters)
         //Waiting for UART event.
         if (xQueueReceive(spp_uart_queue, (void * )&event, (portTickType)portMAX_DELAY)) {
             switch (event.type) {
-            //Event of UART receving data
+            //Event of UART receiving data
             case UART_DATA:
                 if ((event.size)&&(is_connected)) {
                     uint8_t * temp = NULL;
@@ -466,7 +465,7 @@ static void spp_task_init(void)
 static void gap_event_handler(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param)
 {
     esp_err_t err;
-    ESP_LOGE(GATTS_TABLE_TAG, "GAP_EVT, event %d\n", event);
+    ESP_LOGI(GATTS_TABLE_TAG, "GAP_EVT, event %d", event);
 
     switch (event) {
     case ESP_GAP_BLE_ADV_DATA_RAW_SET_COMPLETE_EVT:
@@ -587,6 +586,7 @@ static void gatts_profile_event_handler(esp_gatts_cb_event_t event, esp_gatt_if_
 #endif
         	break;
     	case ESP_GATTS_DISCONNECT_EVT:
+            spp_mtu_size = 23;
     	    is_connected = false;
     	    enable_data_ntf = false;
 #ifdef SUPPORT_HEARTBEAT
@@ -697,5 +697,10 @@ void app_main(void)
 
     spp_task_init();
 
+    esp_err_t local_mtu_ret = esp_ble_gatt_set_local_mtu(500);
+    if (local_mtu_ret){
+        ESP_LOGE(GATTS_TABLE_TAG, "set local  MTU failed, error code = %x", local_mtu_ret);
+    }
+
     return;
 }