ESP32 as a WiFi Station

 In this post, we will go through an example in which the esp32 connects to a wifi softAP as a station 

The reference code is

https://github.com/espressif/esp-idf/tree/master/examples/wifi/getting_started/station 

The SSID and password is defined at the top 

#define EXAMPLE_ESP_WIFI_SSID      CONFIG_ESP_WIFI_SSID #define EXAMPLE_ESP_WIFI_PASS      CONFIG_ESP_WIFI_PASSWORD

Here the CONFIG_XXXXX macros are in sdkconfig.h file 

This configuration file is actually modified when you use the $idf.py menuconfig command

So set the SSID and password of your router using menuconfig 

The code uses the default event loop to register and handle the WIFI connection related events 

Initialize the underlying TCP/IP stack using the following function

void tcpip_adapter_init(void);

Initialize wifi_init_config_t type configuration variable by putting the default values and then initialize the wifi stack

wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT(); ESP_ERROR_CHECK(esp_wifi_init(&cfg));

Create the default event loop & Register for WIFI events to the default event loop 

ESP_ERROR_CHECK(esp_event_loop_create_default()); …….. ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL)); ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL));

Set the SSID and Password to the wifi stack 

wifi_config_t wifi_config = {         .sta = {             .ssid = EXAMPLE_ESP_WIFI_SSID,             .password = EXAMPLE_ESP_WIFI_PASS         },     };

Set the wifi stack as Station Mode and start it 

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() );

Now as the wifi connection events occur it will get hanlded by the handler function 

static void event_handler(void* arg,                            esp_event_base_t event_base,                           int32_t event_id,                            void* event_data) { …………………. ……………….. }

Compile and flash the program 

~/esp/esp-idf/examples/wifi/getting_started/station$ idf.py -p /dev/ttyUSB0 flash monitor

Check the output log