基於ESP-IDF4.1版本
main.c文件如下：
#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.h" #include "esp_log.h" #include "nvs_flash.h" #include "esp_pm.h" #include "lwip/err.h" #include "lwip/sys.h" //值在sdkconfig中配置 #define ESP_WIFI_SSID CONFIG_ESP_WIFI_SSID #define ESP_WIFI_PASS CONFIG_ESP_WIFI_PASSWORD #define ESP_MAXIMUM_RETRY CONFIG_ESP_MAXIMUM_RETRY #define DEFAULT_LISTEN_INTERVAL CONFIG_WIFI_LISTEN_INTERVAL #define DEFAULT_PS_MODE WIFI_PS_MIN_MODEM //事件的位，連接成功和失敗 #define WIFI_CONNECTED_BIT BIT0 #define WIFI_FAIL_BIT BIT1 //FreeRTOS事件組用於表示什么時候建立連接 static EventGroupHandle_t s_wifi_event_group; static const char *TAG = "wifi station"; static int s_retry_num = 0; //事件處理服務 static void event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data) { if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) { esp_wifi_connect(); } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) { if (s_retry_num < ESP_MAXIMUM_RETRY) { esp_wifi_connect(); s_retry_num++; ESP_LOGI(TAG, "retry to connect to the AP"); } else { //事件組置位 xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT); } ESP_LOGI(TAG,"connect to the AP fail"); } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) { ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data; ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip)); s_retry_num = 0; //事件組置位 xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT); } } //wifi初始化 void wifi_init_sta(void) { //創建事件組 s_wifi_event_group = xEventGroupCreate(); ESP_ERROR_CHECK(esp_netif_init()); ESP_ERROR_CHECK(esp_event_loop_create_default()); esp_netif_t *sta_netif = esp_netif_create_default_wifi_sta(); assert(sta_netif); wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT(); ESP_ERROR_CHECK(esp_wifi_init(&cfg)); //注冊事件處理服務 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)); wifi_config_t wifi_config = { .sta = { .ssid = ESP_WIFI_SSID, .password = ESP_WIFI_PASS, //設備從AP監聽信標的間隔 .listen_interval = DEFAULT_LISTEN_INTERVAL, //設置密碼意味着設備將會連接所有安全的模式，包括WEP、WPA。然而這些模式不建議使用，如果你的接入點不支持WPA2，注釋以下行來啟用其他模式 .threshold.authmode = WIFI_AUTH_WPA2_PSK, .pmf_cfg = { .capable = true, .required = false }, }, }; 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, "esp_wifi_set_ps()."); esp_wifi_set_ps(DEFAULT_PS_MODE); ESP_LOGI(TAG, "wifi_init_sta finished."); //事件組等待位，等到連接建立或者超過最大重連數后連接仍然失敗。位的設置是通過事件處理服務 EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group, WIFI_CONNECTED_BIT | WIFI_FAIL_BIT, pdFALSE, pdFALSE, portMAX_DELAY); //通過事件組等待位返回位的值，判斷事件做了什么 if (bits & WIFI_CONNECTED_BIT) { ESP_LOGI(TAG, "connected to ap SSID:%s password:%s", ESP_WIFI_SSID, ESP_WIFI_PASS); } else if (bits & WIFI_FAIL_BIT) { ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s", ESP_WIFI_SSID, ESP_WIFI_PASS); } else { ESP_LOGE(TAG, "UNEXPECTED EVENT"); } //注銷事件處理服務，注銷后，即便此前已注冊的事件再次被發送時，也不會再執行了。 ESP_ERROR_CHECK(esp_event_handler_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler)); ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler)); vEventGroupDelete(s_wifi_event_group); } //啟動 void app_main(void) { //初始化非易失性存儲 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); //配置動態頻率縮放：最高頻率和最低頻率在sdkconfig中配置 esp_pm_config_esp32_t pm_config = { .max_freq_mhz = CONFIG_MAX_CPU_FREQ_MHZ, .min_freq_mhz = CONFIG_MIN_CPU_FREQ_MHZ, .light_sleep_enable = true }; ESP_LOGI(TAG, "ESP_WIFI_MODE_STA"); wifi_init_sta(); }
Kconfig.projbuild文件如下：
menu "Example Configuration" config ESP_WIFI_SSID string "WiFi SSID" default "wifissid" help SSID (network name) for the example to connect to. config ESP_WIFI_PASSWORD string "WiFi Password" default "wifipassword" 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. config WIFI_LISTEN_INTERVAL int "WiFi listen interval" default 3 help Interval for station to listen to beacon from AP. The unit of listen interval is one beacon interval. For example, if beacon interval is 100 ms and listen interval is 3, the interval for station to listen to beacon is 300 ms. choice POWER_SAVE_MODE prompt "power save mode" default POWER_SAVE_MIN_MODEM help Power save mode for the esp32 to use. Modem sleep mode includes minimum and maximum power save modes. In minimum power save mode, station wakes up every DTIM to receive beacon. Broadcast data will not be lost because it is transmitted after DTIM. However, it can not save much more power if DTIM is short for DTIM is determined by AP. In maximum power save mode, station wakes up every listen interval to receive beacon. Broadcast data may be lost because station may be in sleep state at DTIM time. If listen interval is longer, more power is saved but broadcast data is more easy to lose. config POWER_SAVE_NONE bool "none" config POWER_SAVE_MIN_MODEM bool "minimum modem" config POWER_SAVE_MAX_MODEM bool "maximum modem" endchoice choice MAX_CPU_FREQ prompt "Maximum CPU frequency" default MAX_CPU_FREQ_80 help Maximum CPU frequency to use for dynamic frequency scaling. config MAX_CPU_FREQ_80 bool "80 MHz" config MAX_CPU_FREQ_160 bool "160 MHz" config MAX_CPU_FREQ_240 bool "240 MHz" endchoice config MAX_CPU_FREQ_MHZ int default 80 if MAX_CPU_FREQ_80 default 160 if MAX_CPU_FREQ_160 default 240 if MAX_CPU_FREQ_240 choice MIN_CPU_FREQ prompt "Minimum CPU frequency" default MIN_CPU_FREQ_10M help Minimum CPU frequency to use for dynamic frequency scaling. Should be set to XTAL frequency or XTAL frequency divided by integer. config MIN_CPU_FREQ_40M bool "40 MHz (use with 40MHz XTAL)" depends on ESP32_XTAL_FREQ_40 || ESP32_XTAL_FREQ_AUTO config MIN_CPU_FREQ_20M bool "20 MHz (use with 40MHz XTAL)" depends on ESP32_XTAL_FREQ_40 || ESP32_XTAL_FREQ_AUTO config MIN_CPU_FREQ_10M bool "10 MHz (use with 40MHz XTAL)" depends on ESP32_XTAL_FREQ_40 || ESP32_XTAL_FREQ_AUTO config MIN_CPU_FREQ_26M bool "26 MHz (use with 26MHz XTAL)" depends on ESP32_XTAL_FREQ_26 || ESP32_XTAL_FREQ_AUTO config MIN_CPU_FREQ_13M bool "13 MHz (use with 26MHz XTAL)" depends on ESP32_XTAL_FREQ_26 || ESP32_XTAL_FREQ_AUTO endchoice config MIN_CPU_FREQ_MHZ int default 40 if MIN_CPU_FREQ_40M default 20 if MIN_CPU_FREQ_20M default 10 if MIN_CPU_FREQ_10M default 26 if MIN_CPU_FREQ_26M default 13 if MIN_CPU_FREQ_13M endmenu
原文：https://gitee.com/EspressifSystems/esp-idf