1. modify simple wifi example

2. add README file

examples/wifi/getting_started/softAP/Makefile

@@ -3,7 +3,7 @@
 # project subdirectory.
 #
 
-PROJECT_NAME := simple_wifi
+PROJECT_NAME := wifi_softAP
 
 include $(IDF_PATH)/make/project.mk
 

examples/wifi/getting_started/softAP/README.md

@@ -0,0 +1,42 @@
+# WiFi softAP example
+
+(See the README.md file in the upper level 'examples' directory for more information about examples.)
+
+
+## How to use example
+
+### Configure the project
+
+```
+make menuconfig
+```
+
+* Set serial port under Serial Flasher Options.
+
+* Set WiFi SSID and WiFi Password and Maximal STA connections under Example Configuration Options.
+
+### Build and Flash
+
+Build the project and flash it to the board, then run monitor tool to view serial output:
+
+```
+make -j4 flash monitor
+```
+
+(To exit the serial monitor, type ``Ctrl-]``.)
+
+See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
+
+## Example Output
+
+There is the console output for this example:
+
+```
+I (917) phy: phy_version: 3960, 5211945, Jul 18 2018, 10:40:07, 0, 0
+I (917) wifi: mode : softAP (30:ae:a4:80:45:69)
+I (917) wifi softAP: wifi_init_softap finished.SSID:myssid password:mypassword
+I (26457) wifi: n:1 0, o:1 0, ap:1 1, sta:255 255, prof:1
+I (26457) wifi: station: 70:ef:00:43:96:67 join, AID=1, bg, 20
+I (26467) wifi softAP: station:70:ef:00:43:96:67 join, AID=1
+I (27657) tcpip_adapter: softAP assign IP to station,IP is: 192.168.4.2
+```

examples/wifi/getting_started/softAP/main/Kconfig.projbuild

@@ -1,22 +1,5 @@
 menu "Example Configuration"
 
-choice ESP_WIFI_MODE
-    prompt "AP or STA"
-    default ESP_WIFI_IS_STATION
-    help
-        Whether the esp32 is softAP or station.
-
-config ESP_WIFI_IS_SOFTAP
-    bool "SoftAP"
-config ESP_WIFI_IS_STATION
-    bool "Station"
-endchoice
-
-config ESP_WIFI_MODE_AP
-    bool
-    default y if ESP_WIFI_IS_SOFTAP
-    default n if ESP_WIFI_IS_STATION
-
 config ESP_WIFI_SSID
     string "WiFi SSID"
     default "myssid"
@@ -30,7 +13,7 @@ config ESP_WIFI_PASSWORD
 	WiFi password (WPA or WPA2) for the example to use.
 		
 config MAX_STA_CONN
-    int "Max STA conn"
+    int "Maximal STA connections"
     default 4
     help
 	Max number of the STA connects to AP.

examples/wifi/getting_started/softAP/main/softap_example_main.c

@@ -1,4 +1,4 @@
-/* Simple WiFi Example
+/*  WiFi softAP Example
 
    This example code is in the Public Domain (or CC0 licensed, at your option.)
 
@@ -19,38 +19,23 @@
 #include "lwip/err.h"
 #include "lwip/sys.h"
 
-/* The examples use simple WiFi configuration that you can set via
+/* The examples use WiFi configuration that you can set via 'make menuconfig'.
-   'make menuconfig'.
 
    If you'd rather not, just change the below entries to strings with
    the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
 */
-#define EXAMPLE_ESP_WIFI_MODE_AP   CONFIG_ESP_WIFI_MODE_AP //TRUE:AP FALSE:STA
 #define EXAMPLE_ESP_WIFI_SSID      CONFIG_ESP_WIFI_SSID
 #define EXAMPLE_ESP_WIFI_PASS      CONFIG_ESP_WIFI_PASSWORD
 #define EXAMPLE_MAX_STA_CONN       CONFIG_MAX_STA_CONN
 
 /* FreeRTOS event group to signal when we are connected*/
-static EventGroupHandle_t wifi_event_group;
+static EventGroupHandle_t s_wifi_event_group;
 
-/* The event group allows multiple bits for each event,
+static const char *TAG = "wifi softAP";
-   but we only care about one event - are we connected
-   to the AP with an IP? */
-const int WIFI_CONNECTED_BIT = BIT0;
-
-static const char *TAG = "simple wifi";
 
 static esp_err_t event_handler(void *ctx, system_event_t *event)
 {
     switch(event->event_id) {
-    case SYSTEM_EVENT_STA_START:
-        esp_wifi_connect();
-        break;
-    case SYSTEM_EVENT_STA_GOT_IP:
-        ESP_LOGI(TAG, "got ip:%s",
-                 ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
-        xEventGroupSetBits(wifi_event_group, WIFI_CONNECTED_BIT);
-        break;
     case SYSTEM_EVENT_AP_STACONNECTED:
         ESP_LOGI(TAG, "station:"MACSTR" join, AID=%d",
                  MAC2STR(event->event_info.sta_connected.mac),
@@ -61,10 +46,6 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
                  MAC2STR(event->event_info.sta_disconnected.mac),
                  event->event_info.sta_disconnected.aid);
         break;
-    case SYSTEM_EVENT_STA_DISCONNECTED:
-        esp_wifi_connect();
-        xEventGroupClearBits(wifi_event_group, WIFI_CONNECTED_BIT);
-        break;
     default:
         break;
     }
@@ -73,7 +54,7 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
 
 void wifi_init_softap()
 {
-    wifi_event_group = xEventGroupCreate();
+    s_wifi_event_group = xEventGroupCreate();
 
     tcpip_adapter_init();
     ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
@@ -101,31 +82,6 @@ void wifi_init_softap()
              EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
 }
 
-void wifi_init_sta()
-{
-    wifi_event_group = xEventGroupCreate();
-
-    tcpip_adapter_init();
-    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL) );
-
-    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
-    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
-    wifi_config_t wifi_config = {
-        .sta = {
-            .ssid = EXAMPLE_ESP_WIFI_SSID,
-            .password = EXAMPLE_ESP_WIFI_PASS
-        },
-    };
-
-    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );
-    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
-    ESP_ERROR_CHECK(esp_wifi_start() );
-
-    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_main()
 {
     //Initialize NVS
@@ -136,12 +92,6 @@ void app_main()
     }
     ESP_ERROR_CHECK(ret);
     
-#if EXAMPLE_ESP_WIFI_MODE_AP
     ESP_LOGI(TAG, "ESP_WIFI_MODE_AP");
     wifi_init_softap();
-#else
-    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");
-    wifi_init_sta();
-#endif /*EXAMPLE_ESP_WIFI_MODE_AP*/
-
 }

examples/wifi/getting_started/station/Makefile

@@ -0,0 +1,9 @@
+#
+# This is a project Makefile. It is assumed the directory this Makefile resides in is a
+# project subdirectory.
+#
+
+PROJECT_NAME := wifi_station
+
+include $(IDF_PATH)/make/project.mk
+

examples/wifi/getting_started/station/README.md

@@ -0,0 +1,97 @@
+# WiFi station example
+
+(See the README.md file in the upper level 'examples' directory for more information about examples.)
+
+
+## How to use example
+
+### Configure the project
+
+```
+make menuconfig
+```
+
+* Set serial port under Serial Flasher Options.
+
+* Set WiFi SSID and WiFi Password and Maximum retry under Example Configuration Options.
+
+### Build and Flash
+
+Build the project and flash it to the board, then run monitor tool to view serial output:
+
+```
+make -j4 flash monitor
+```
+
+(To exit the serial monitor, type ``Ctrl-]``.)
+
+See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
+
+## Example Output
+
+There is the console output for station connects to ap successfully:
+```
+I (727) wifi station: ESP_WIFI_MODE_STA
+I (727) wifi: wifi driver task: 3ffc0c68, prio:23, stack:3584, core=0
+I (727) wifi: wifi firmware version: 19b3110
+I (727) wifi: config NVS flash: enabled
+I (727) wifi: config nano formating: disabled
+I (737) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (747) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (777) wifi: Init dynamic tx buffer num: 32
+I (777) wifi: Init data frame dynamic rx buffer num: 32
+I (777) wifi: Init management frame dynamic rx buffer num: 32
+I (777) wifi: Init static rx buffer size: 1600
+I (787) wifi: Init static rx buffer num: 10
+I (787) wifi: Init dynamic rx buffer num: 32
+I (907) phy: phy_version: 3960, 5211945, Jul 18 2018, 10:40:07, 0, 0
+I (907) wifi: mode : sta (30:ae:a4:80:45:68)
+I (907) wifi station: wifi_init_sta finished.
+I (907) wifi station: connect to ap SSID:myssid password:mypassword
+I (1027) wifi: n:6 0, o:1 0, ap:255 255, sta:6 0, prof:1
+I (2017) wifi: state: init -> auth (b0)
+I (2017) wifi: state: auth -> assoc (0)
+I (2027) wifi: state: assoc -> run (10)
+I (2067) wifi: connected with myssid, channel 6
+I (2067) wifi: pm start, type: 1
+
+I (3227) event: sta ip: 172.20.10.7, mask: 255.255.255.240, gw: 172.20.10.1
+I (3227) wifi station: got ip:172.20.10.7
+```
+
+There is the console output for station connects to ap failed:
+```
+I (728) wifi station: ESP_WIFI_MODE_STA
+I (728) wifi: wifi driver task: 3ffc0c68, prio:23, stack:3584, core=0
+I (728) wifi: wifi firmware version: 19b3110
+I (728) wifi: config NVS flash: enabled
+I (738) wifi: config nano formating: disabled
+I (738) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (748) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (778) wifi: Init dynamic tx buffer num: 32
+I (778) wifi: Init data frame dynamic rx buffer num: 32
+I (778) wifi: Init management frame dynamic rx buffer num: 32
+I (788) wifi: Init static rx buffer size: 1600
+I (788) wifi: Init static rx buffer num: 10
+I (788) wifi: Init dynamic rx buffer num: 32
+I (908) phy: phy_version: 3960, 5211945, Jul 18 2018, 10:40:07, 0, 0
+I (908) wifi: mode : sta (30:ae:a4:80:45:68)
+I (908) wifi station: wifi_init_sta finished.
+I (918) wifi station: connect to ap SSID:myssid password:mypassword
+I (3328) wifi station: retry to connect to the AP
+I (3328) wifi station: connect to the AP fail
+
+I (5738) wifi station: retry to connect to the AP
+I (5738) wifi station: connect to the AP fail
+
+I (8148) wifi station: retry to connect to the AP
+I (8148) wifi station: connect to the AP fail
+
+I (10558) wifi station: retry to connect to the AP
+I (10558) wifi station: connect to the AP fail
+
+I (12968) wifi station: retry to connect to the AP
+I (12968) wifi station: connect to the AP fail
+
+I (15378) wifi station: connect to the AP fail
+```

examples/wifi/getting_started/station/main/Kconfig.projbuild

@@ -0,0 +1,20 @@
+menu "Example Configuration"
+
+config ESP_WIFI_SSID
+    string "WiFi SSID"
+    default "myssid"
+    help
+	SSID (network name) for the example to connect to.
+
+config ESP_WIFI_PASSWORD
+    string "WiFi Password"
+    default "mypassword"
+    help
+	WiFi password (WPA or WPA2) for the example to use.
+
+config ESP_MAXIMUM_RETRY
+    int "Maximum retry"
+    default 5
+    help
+	Set the Maximum retry to avoid station reconnecting to the AP unlimited when the AP is really inexistent.  
+endmenu

examples/wifi/getting_started/station/main/component.mk

@@ -0,0 +1,8 @@
+#
+# Main component makefile.
+#
+# This Makefile can be left empty. By default, it will take the sources in the 
+# src/ directory, compile them and link them into lib(subdirectory_name).a 
+# in the build directory. This behaviour is entirely configurable,
+# please read the ESP-IDF documents if you need to do this.
+#

examples/wifi/getting_started/station/main/station_example_main.c

@@ -0,0 +1,108 @@
+/* WiFi station Example
+
+   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.
+*/
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/event_groups.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "esp_event_loop.h"
+#include "esp_log.h"
+#include "nvs_flash.h"
+
+#include "lwip/err.h"
+#include "lwip/sys.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
+   the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
+*/
+#define EXAMPLE_ESP_WIFI_SSID      CONFIG_ESP_WIFI_SSID
+#define EXAMPLE_ESP_WIFI_PASS      CONFIG_ESP_WIFI_PASSWORD
+#define EXAMPLE_ESP_MAXIMUM_RETRY  CONFIG_ESP_MAXIMUM_RETRY
+
+/* 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, but we only care about one event 
+ * - are we connected to the AP with an IP? */
+const int WIFI_CONNECTED_BIT = BIT0;
+
+static const char *TAG = "wifi station";
+
+static int s_retry_num = 0;
+
+static esp_err_t event_handler(void *ctx, system_event_t *event)
+{
+    switch(event->event_id) {
+    case SYSTEM_EVENT_STA_START:
+        esp_wifi_connect();
+        break;
+    case SYSTEM_EVENT_STA_GOT_IP:
+        ESP_LOGI(TAG, "got ip:%s",
+                 ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
+        s_retry_num = 0;
+        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+        break;
+    case SYSTEM_EVENT_STA_DISCONNECTED:
+        {
+            if (s_retry_num < EXAMPLE_ESP_MAXIMUM_RETRY) {
+                esp_wifi_connect();
+                xEventGroupClearBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+                s_retry_num++;
+                ESP_LOGI(TAG,"retry to connect to the AP");
+            }
+            ESP_LOGI(TAG,"connect to the AP fail\n");
+            break;
+        }
+    default:
+        break;
+    }
+    return ESP_OK;
+}
+
+void wifi_init_sta()
+{
+    s_wifi_event_group = xEventGroupCreate();
+
+    tcpip_adapter_init();
+    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL) );
+
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    wifi_config_t wifi_config = {
+        .sta = {
+            .ssid = EXAMPLE_ESP_WIFI_SSID,
+            .password = EXAMPLE_ESP_WIFI_PASS
+        },
+    };
+
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );
+    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
+    ESP_ERROR_CHECK(esp_wifi_start() );
+
+    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_main()
+{
+    //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());
+      ret = nvs_flash_init();
+    }
+    ESP_ERROR_CHECK(ret);
+    
+    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");
+    wifi_init_sta();
+}