add pppos client restart in example

Closes https://github.com/espressif/esp-idf/issues/4268

examples/protocols/pppos_client/README.md

@@ -52,7 +52,7 @@ See the [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/l
 
 ## Example Output
 
-The example will get module and operator's information after start up, and then go into PPP mode to start mqtt client operations. This example will also send a short message to someone's phone if you have enabled this feature in menuconfig.
+The example will get module and operator's information after start up, and then go into PPP mode to start mqtt client operations. This example will also send a short message to someone's phone if you have enabled this feature in menuconfig. The PPP connection will get restarted after 60 seconds.
 
 ### BG96 Output
 

examples/protocols/pppos_client/main/pppos_client_main.c

@@ -227,11 +227,6 @@ void app_main(void)
 
     event_group = xEventGroupCreate();
 
-    // Init netif object
-    esp_netif_config_t cfg = ESP_NETIF_DEFAULT_PPP();
-    esp_netif_t *esp_netif = esp_netif_new(&cfg);
-    assert(esp_netif);
-
     /* create dte object */
     esp_modem_dte_config_t config = ESP_MODEM_DTE_DEFAULT_CONFIG();
     /* setup UART specific configuration based on kconfig options */
@@ -245,15 +240,27 @@ void app_main(void)
     config.event_queue_size = CONFIG_EXAMPLE_MODEM_UART_EVENT_QUEUE_SIZE;
     config.event_task_stack_size = CONFIG_EXAMPLE_MODEM_UART_EVENT_TASK_STACK_SIZE;
     config.event_task_priority = CONFIG_EXAMPLE_MODEM_UART_EVENT_TASK_PRIORITY;
-    config.line_buffer_size = CONFIG_EXAMPLE_MODEM_UART_RX_BUFFER_SIZE/2;
+    config.line_buffer_size = CONFIG_EXAMPLE_MODEM_UART_RX_BUFFER_SIZE / 2;
+
     modem_dte_t *dte = esp_modem_dte_init(&config);
     /* Register event handler */
     ESP_ERROR_CHECK(esp_modem_set_event_handler(dte, modem_event_handler, ESP_EVENT_ANY_ID, NULL));
+
+    // Init netif object
+    esp_netif_config_t cfg = ESP_NETIF_DEFAULT_PPP();
+    esp_netif_t *esp_netif = esp_netif_new(&cfg);
+    assert(esp_netif);
+
+    void *modem_netif_adapter = esp_modem_netif_setup(dte);
+    esp_modem_netif_set_default_handlers(modem_netif_adapter, esp_netif);
+
+    while (1) {
+        modem_dce_t *dce = NULL;
         /* create dce object */
 #if CONFIG_EXAMPLE_MODEM_DEVICE_SIM800
-    modem_dce_t *dce = sim800_init(dte);
+        dce = sim800_init(dte);
 #elif CONFIG_EXAMPLE_MODEM_DEVICE_BG96
-    modem_dce_t *dce = bg96_init(dte);
+        dce = bg96_init(dte);
 #else
 #error "Unsupported DCE"
 #endif
@@ -277,12 +284,11 @@ void app_main(void)
 #if !defined(CONFIG_EXAMPLE_MODEM_PPP_AUTH_NONE) && (defined(CONFIG_LWIP_PPP_PAP_SUPPORT) || defined(CONFIG_LWIP_PPP_CHAP_SUPPORT))
         esp_netif_ppp_set_auth(esp_netif, auth_type, CONFIG_EXAMPLE_MODEM_PPP_AUTH_USERNAME, CONFIG_EXAMPLE_MODEM_PPP_AUTH_PASSWORD);
 #endif
-    void *modem_netif_adapter = esp_modem_netif_setup(dte);
-    esp_modem_netif_set_default_handlers(modem_netif_adapter, esp_netif);
         /* attach the modem to the network interface */
         esp_netif_attach(esp_netif, modem_netif_adapter);
         /* Wait for IP address */
         xEventGroupWaitBits(event_group, CONNECT_BIT, pdTRUE, pdTRUE, portMAX_DELAY);
+
         /* Config MQTT */
         esp_mqtt_client_config_t mqtt_config = {
             .uri = BROKER_URL,
@@ -292,11 +298,10 @@ void app_main(void)
         esp_mqtt_client_start(mqtt_client);
         xEventGroupWaitBits(event_group, GOT_DATA_BIT, pdTRUE, pdTRUE, portMAX_DELAY);
         esp_mqtt_client_destroy(mqtt_client);
+
         /* Exit PPP mode */
         ESP_ERROR_CHECK(esp_modem_stop_ppp(dte));
-    /* Destroy the netif adapter withe events, which internally frees also the esp-netif instance */
+
-    esp_modem_netif_clear_default_handlers(modem_netif_adapter);
-    esp_modem_netif_teardown(modem_netif_adapter);
         xEventGroupWaitBits(event_group, STOP_BIT, pdTRUE, pdTRUE, portMAX_DELAY);
 #if CONFIG_EXAMPLE_SEND_MSG
         const char *message = "Welcome to ESP32!";
@@ -307,5 +312,13 @@ void app_main(void)
         ESP_ERROR_CHECK(dce->power_down(dce));
         ESP_LOGI(TAG, "Power down");
         ESP_ERROR_CHECK(dce->deinit(dce));
+
+        ESP_LOGI(TAG, "Restart after 60 seconds");
+        vTaskDelay(pdMS_TO_TICKS(60000));
+    }
+
+    /* Destroy the netif adapter withe events, which internally frees also the esp-netif instance */
+    esp_modem_netif_clear_default_handlers(modem_netif_adapter);
+    esp_modem_netif_teardown(modem_netif_adapter);
     ESP_ERROR_CHECK(dte->deinit(dte));
 }