Example "camera_web_server" updated to be compatible with ESP-IDF v4.2.1-dirty

Updated "app_wifi" to be compatible with both "esp_event" library and "ESP-NETIF" library.
Updated "app_mdns" to be compatible with "esp_event" library.
Tested the program successfully on the ESP-AI-Thinker with the OV2640 camera.

examples/single_chip/camera_web_server/main/app_mdns.c

@@ -31,6 +31,7 @@
 #include "esp_camera.h"
 #include "mdns.h"
 #include "app_camera.h"
+#include "app_wifi.h"
 
 static const char *TAG = "camera mdns";
 
@@ -82,11 +83,11 @@ const char * app_mdns_query(size_t * out_len)
     *p++ = '[';
 
     //add own data first
-    tcpip_adapter_ip_info_t ip;
+    esp_netif_ip_info_t ip;
     if (strlen(CONFIG_ESP_WIFI_SSID)) {
-    	tcpip_adapter_get_ip_info(TCPIP_ADAPTER_IF_STA, &ip);
+        esp_netif_get_ip_info(STA_netif, &ip);
     } else {
-    	tcpip_adapter_get_ip_info(TCPIP_ADAPTER_IF_AP, &ip);
+        esp_netif_get_ip_info(AP_netif, &ip);
     }
     *p++ = '{';
     p += sprintf(p, "\"instance\":\"%s\",", iname);
@@ -135,7 +136,7 @@ const char * app_mdns_query(size_t * out_len)
         }
         a = r->addr;
         while(a){
-            if(a->addr.type != IPADDR_TYPE_V6){
+            if(a->addr.type != ESP_IPADDR_TYPE_V6){
                 p += sprintf(p, "\"ip\":\"" IPSTR "\",", IP2STR(&(a->addr.u_addr.ip4)));
             	p += sprintf(p, "\"id\":\"" IPSTR ":%u\",", IP2STR(&(a->addr.u_addr.ip4)), r->port);
                 break;
@@ -166,7 +167,7 @@ void app_mdns_update_framesize(int size)
     }
 }
 
-void app_mdns_main()
+void app_mdns_main(void)
 {	
     uint8_t mac[6];
 

examples/single_chip/camera_web_server/main/app_wifi.c

@@ -25,7 +25,7 @@
 #include "freertos/event_groups.h"
 #include "esp_system.h"
 #include "esp_wifi.h"
-#include "esp_event_loop.h"
+#include "esp_event.h"
 #include "esp_log.h"
 #include "nvs_flash.h"
 #include "sdkconfig.h"
@@ -33,8 +33,6 @@
 #include "lwip/err.h"
 #include "lwip/sys.h"
 
-#include "mdns.h"
-
 /* The examples use WiFi configuration that you can set via 'make menuconfig'.
 
    If you'd rather not, just change the below entries to strings with
@@ -49,111 +47,185 @@
 #define EXAMPLE_IP_ADDR            CONFIG_SERVER_IP
 #define EXAMPLE_ESP_WIFI_AP_CHANNEL CONFIG_ESP_WIFI_AP_CHANNEL
 
+/* FreeRTOS event group to signal when we are connected*/
+static EventGroupHandle_t s_wifi_event_group;
+
+/* The event group allows multiple bits for each event,
+ * For STA events handling, we only care about two events:
+ * - we are connected to the AP with an IP
+ * - we failed to connect after the maximum amount of retries */
+#define WIFI_CONNECTED_BIT BIT0
+#define WIFI_FAIL_BIT      BIT1
+
 static const char *TAG = "camera wifi";
 
 static int s_retry_num = 0;
 
-static esp_err_t event_handler(void *ctx, system_event_t *event)
+esp_netif_t *AP_netif, *STA_netif;
+
+static void wifi_event_handler(void* arg, esp_event_base_t event_base,
+                                int32_t event_id, void* event_data)
 {
-    switch(event->event_id) {
+    if (event_id == WIFI_EVENT_AP_STACONNECTED) {
-    case SYSTEM_EVENT_AP_STACONNECTED:
+        wifi_event_ap_staconnected_t* event = (wifi_event_ap_staconnected_t*) event_data;
-        ESP_LOGI(TAG, "station:" MACSTR " join, AID=%d",
+        ESP_LOGI(TAG, "station: " MACSTR "join, AID=%d",
-                 MAC2STR(event->event_info.sta_connected.mac),
+                 MAC2STR(event->mac), 
-                 event->event_info.sta_connected.aid);
+                 event->aid);
-        break;
+    } else if (event_id == WIFI_EVENT_AP_STADISCONNECTED) {
-    case SYSTEM_EVENT_AP_STADISCONNECTED:
+        wifi_event_ap_stadisconnected_t* event = (wifi_event_ap_stadisconnected_t*) event_data;
         ESP_LOGI(TAG, "station:" MACSTR "leave, AID=%d",
-                 MAC2STR(event->event_info.sta_disconnected.mac),
+                 MAC2STR(event->mac), 
-                 event->event_info.sta_disconnected.aid);
+                 event->aid);
-        break;
+    }
-    case SYSTEM_EVENT_STA_START:
+
-        esp_wifi_connect();
+    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
-        break;
+        esp_wifi_connect();
-    case SYSTEM_EVENT_STA_GOT_IP:
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
-        ESP_LOGI(TAG, "got ip:%s",
+        if (s_retry_num < EXAMPLE_ESP_MAXIMUM_RETRY) {
-                 ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
+            esp_wifi_connect();
-        s_retry_num = 0;
+            s_retry_num++;
-        break;
+            ESP_LOGI(TAG, "retry to connect to the AP");
-    case SYSTEM_EVENT_STA_DISCONNECTED:
+        } else {
-        {
+            xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
-            if (s_retry_num < EXAMPLE_ESP_MAXIMUM_RETRY) {
+        }
-                esp_wifi_connect();
+        ESP_LOGI(TAG,"connect to the AP fail");
-                s_retry_num++;
+    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
-                ESP_LOGI(TAG,"retry to connect to the AP");
+        ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
-            }
+        ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));
-            ESP_LOGI(TAG,"connect to the AP fail");
+        s_retry_num = 0;
-            break;
+        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
-        }
-    default:
-        break;
     }
-    mdns_handle_system_event(ctx, event);
-    return ESP_OK;
 }
 
-void wifi_init_softap()
+void wifi_init_softap(void)
 {
+    /* default event loop from esp_event library */
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    AP_netif = esp_netif_create_default_wifi_ap();
+    assert(AP_netif);
+
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
+                                                        ESP_EVENT_ANY_ID,
+                                                        &wifi_event_handler,
+                                                        NULL,
+                                                        NULL));
+
     if (strcmp(EXAMPLE_IP_ADDR, "192.168.4.1"))
     {
         int a, b, c, d;
         sscanf(EXAMPLE_IP_ADDR, "%d.%d.%d.%d", &a, &b, &c, &d);
-        tcpip_adapter_ip_info_t ip_info;
+        esp_netif_ip_info_t ip_info;
-        IP4_ADDR(&ip_info.ip, a, b, c, d);
+        esp_netif_set_ip4_addr(&ip_info.ip, a, b, c, d);
-        IP4_ADDR(&ip_info.gw, a, b, c, d);
+        esp_netif_set_ip4_addr(&ip_info.gw, a, b, c, d);
-        IP4_ADDR(&ip_info.netmask, 255, 255, 255, 0);
+        esp_netif_set_ip4_addr(&ip_info.netmask, 255, 255, 255, 0);
-        ESP_ERROR_CHECK(tcpip_adapter_dhcps_stop(WIFI_IF_AP));
+        ESP_ERROR_CHECK(esp_netif_dhcps_stop(AP_netif));
-        ESP_ERROR_CHECK(tcpip_adapter_set_ip_info(WIFI_IF_AP, &ip_info));
+        ESP_ERROR_CHECK(esp_netif_set_ip_info(AP_netif, &ip_info));
-        ESP_ERROR_CHECK(tcpip_adapter_dhcps_start(WIFI_IF_AP));
+        ESP_ERROR_CHECK(esp_netif_dhcps_start(AP_netif));
     }
+
     wifi_config_t wifi_config;
     memset(&wifi_config, 0, sizeof(wifi_config_t));
+
     snprintf((char*)wifi_config.ap.ssid, 32, "%s", EXAMPLE_ESP_WIFI_AP_SSID);
     wifi_config.ap.ssid_len = strlen((char*)wifi_config.ap.ssid);
     snprintf((char*)wifi_config.ap.password, 64, "%s", EXAMPLE_ESP_WIFI_AP_PASS);
+    
     wifi_config.ap.max_connection = EXAMPLE_MAX_STA_CONN;
     wifi_config.ap.authmode = WIFI_AUTH_WPA_WPA2_PSK;
+
     if (strlen(EXAMPLE_ESP_WIFI_AP_PASS) == 0) {
         wifi_config.ap.authmode = WIFI_AUTH_OPEN;
     }
+    
     if (strlen(EXAMPLE_ESP_WIFI_AP_CHANNEL)) {
         int channel;
         sscanf(EXAMPLE_ESP_WIFI_AP_CHANNEL, "%d", &channel);
         wifi_config.ap.channel = channel;
     }
 
-    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &wifi_config));
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
+    // "esp_wifi_set_config" can be called only when specified interface is enabled, otherwise, API fail
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_AP, &wifi_config));
 
-    ESP_LOGI(TAG, "wifi_init_softap finished.SSID:%s password:%s",
+    ESP_LOGI(TAG, "wifi_init_softap finished. SSID:%s password:%s channel:%s",
-             EXAMPLE_ESP_WIFI_AP_SSID, EXAMPLE_ESP_WIFI_AP_PASS);
+             EXAMPLE_ESP_WIFI_AP_SSID, EXAMPLE_ESP_WIFI_AP_PASS, EXAMPLE_ESP_WIFI_AP_CHANNEL);
 }
 
-void wifi_init_sta()
+void wifi_init_sta(void)
 {
-    wifi_config_t wifi_config;
+    s_wifi_event_group = xEventGroupCreate();
-    memset(&wifi_config, 0, sizeof(wifi_config_t));
+
+    ESP_ERROR_CHECK(esp_netif_init());
+
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    STA_netif = esp_netif_create_default_wifi_sta();
+    assert(STA_netif);
+
+    esp_event_handler_instance_t instance_any_id;
+    esp_event_handler_instance_t instance_got_ip;
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
+                                                        ESP_EVENT_ANY_ID,
+                                                        &wifi_event_handler,
+                                                        NULL,
+                                                        &instance_any_id));
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,
+                                                        IP_EVENT_STA_GOT_IP,
+                                                        &wifi_event_handler,
+                                                        NULL,
+                                                        &instance_got_ip));
+
+    wifi_config_t wifi_config = {
+        .sta = {
+            .threshold.authmode = WIFI_AUTH_WPA_WPA2_PSK,
+            .pmf_cfg = {
+                .capable = true,
+                .required = false
+            },
+        },
+    };
+    
     snprintf((char*)wifi_config.sta.ssid, 32, "%s", EXAMPLE_ESP_WIFI_SSID);
     snprintf((char*)wifi_config.sta.password, 64, "%s", EXAMPLE_ESP_WIFI_PASS);
 
-    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config) );
 
     ESP_LOGI(TAG, "wifi_init_sta finished.");
-    ESP_LOGI(TAG, "connect to ap SSID:%s password:%s",
-             EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
-}
 
-void app_wifi_main()
+    /* Waiting until either the connection is established (WIFI_CONNECTED_BIT) or connection failed for the maximum
-{
+     * number of re-tries (WIFI_FAIL_BIT). The bits are set by event_handler() (see above) */
-    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,
-    wifi_mode_t mode = WIFI_MODE_NULL;
+            WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
+            pdFALSE,
+            pdFALSE,
+            portMAX_DELAY);
+    
+    /* xEventGroupWaitBits() returns the bits before the call returned, 
+     * hence we can test which event actually happened. */
 
-    if (strlen(EXAMPLE_ESP_WIFI_AP_SSID) && strlen(EXAMPLE_ESP_WIFI_SSID)) {
+    if (bits & WIFI_CONNECTED_BIT) {
-        mode = WIFI_MODE_APSTA;
+        ESP_LOGI(TAG, "connected to ap SSID:%s password:%s",
-    } else if (strlen(EXAMPLE_ESP_WIFI_AP_SSID)) {
+                 EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
-        mode = WIFI_MODE_AP;
+    } else if (bits & WIFI_FAIL_BIT) {
-    } else if (strlen(EXAMPLE_ESP_WIFI_SSID)) {
+        ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s",
-        mode = WIFI_MODE_STA;
+                 EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
+    } else {
+        ESP_LOGE(TAG, "UNEXPECTED EVENT");
     }
 
+    /* The event will not be processed after unregister */
+    ESP_ERROR_CHECK(esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, instance_got_ip));
+    ESP_ERROR_CHECK(esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id));
+    
+    vEventGroupDelete(s_wifi_event_group);
+}
+
+void app_wifi_main(void)
+{
+    //Initialize NVS
     esp_err_t ret = nvs_flash_init();
     if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
       ESP_ERROR_CHECK(nvs_flash_erase());
@@ -161,23 +233,35 @@ void app_wifi_main()
     }
     ESP_ERROR_CHECK(ret);
 
+    /* Always use WIFI_INIT_CONFIG_DEFAULT macro to init the config to default values, 
+     * this can guarantee all the fields got correct value when more fields are added 
+     * into wifi_init_config_t in future release. */
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    /* esp_wifi_init API must be called before all other WiFi API can be called */
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    
+    wifi_mode_t mode = WIFI_MODE_NULL;
+
+    if (strlen(EXAMPLE_ESP_WIFI_AP_SSID) && strlen(EXAMPLE_ESP_WIFI_SSID)) {
+        mode = WIFI_MODE_APSTA;
+        ESP_LOGI(TAG, "WIFI_MODE_APSTA");
+        ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_APSTA));
+    } else if (strlen(EXAMPLE_ESP_WIFI_AP_SSID)) {
+        mode = WIFI_MODE_AP;
+        ESP_LOGI(TAG, "WIFI_MODE_AP");
+        wifi_init_softap();
+    } else if (strlen(EXAMPLE_ESP_WIFI_SSID)) {
+        mode = WIFI_MODE_STA;
+        ESP_LOGI(TAG, "WIFI_MODE_STA");
+        wifi_init_sta();
+    }
+
     if (mode == WIFI_MODE_NULL) {
         ESP_LOGW(TAG,"Neither AP or STA have been configured. WiFi will be off.");
         return;
     }
 
-    tcpip_adapter_init();
-    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
-    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
-    ESP_ERROR_CHECK(esp_wifi_set_mode(mode));
-
-    if (mode & WIFI_MODE_AP) {
-        wifi_init_softap();
-    }
-
-    if (mode & WIFI_MODE_STA) {
-        wifi_init_sta();
-    }
     ESP_ERROR_CHECK(esp_wifi_start());
-    ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE));
+    
+    ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE)); // Set current WiFi power save type.
 }

examples/single_chip/camera_web_server/main/include/app_mdns.h

@@ -20,7 +20,7 @@ extern "C" {
 
 #include <stddef.h>
 
-void app_mdns_main();
+void app_mdns_main(void);
 void app_mdns_update_framesize(int size);
 const char * app_mdns_query(size_t * out_len);
 

examples/single_chip/camera_web_server/main/include/app_wifi.h

@@ -28,7 +28,12 @@
 extern "C" {
 #endif
 
-void app_wifi_main();
+#include "esp_netif.h"
+
+extern esp_netif_t *AP_netif;
+extern esp_netif_t *STA_netif;
+
+void app_wifi_main(void);
 
 #ifdef __cplusplus
 }