ESP32 WIFI 概述
- WIFI 库支持配置及监控 ESP32 WIFI 连网功能。
- 支持配置
- station 模式（即 STA 模式或 WIFI 客户端模式），此时 ESP32 连接到接入点（AP）。
- AP 模式（即 soft-AP 模式或接入点模式），此时 station 接入点 ESP32。
- AP-STA 共存模式（ESP32 既是接入点，同时又作为 station 连接到另一个接入点）。
- 上述模式的各种安全模式（WPA、WPA2 及 WEP 等）。
- 扫描接入点（包括主动扫描和被动扫描）。
- 使用混杂模式监控 IEEE802.11 WIFI 数据包。
宏定义 WIFI_INIT_CONFIG_DEFAULT
- 配置
wifi_init_config_t 结构体的默认值。
#define WIFI_INIT_CONFIG_DEFAULT() { \
.event_handler = &esp_event_send_internal, \
.osi_funcs = &g_wifi_osi_funcs, \
.wpa_crypto_funcs = g_wifi_default_wpa_crypto_funcs, \
.static_rx_buf_num = CONFIG_ESP32_WIFI_STATIC_RX_BUFFER_NUM,\
.dynamic_rx_buf_num = CONFIG_ESP32_WIFI_DYNAMIC_RX_BUFFER_NUM,\
.tx_buf_type = CONFIG_ESP32_WIFI_TX_BUFFER_TYPE,\
.static_tx_buf_num = WIFI_STATIC_TX_BUFFER_NUM,\
.dynamic_tx_buf_num = WIFI_DYNAMIC_TX_BUFFER_NUM,\
.cache_tx_buf_num = WIFI_CACHE_TX_BUFFER_NUM,\
.csi_enable = WIFI_CSI_ENABLED,\
.ampdu_rx_enable = WIFI_AMPDU_RX_ENABLED,\
.ampdu_tx_enable = WIFI_AMPDU_TX_ENABLED,\
.amsdu_tx_enable = WIFI_AMSDU_TX_ENABLED,\
.nvs_enable = WIFI_NVS_ENABLED,\
.nano_enable = WIFI_NANO_FORMAT_ENABLED,\
.rx_ba_win = WIFI_DEFAULT_RX_BA_WIN,\
.wifi_task_core_id = WIFI_TASK_CORE_ID,\
.beacon_max_len = WIFI_SOFTAP_BEACON_MAX_LEN, \
.mgmt_sbuf_num = WIFI_MGMT_SBUF_NUM, \
.feature_caps = g_wifi_feature_caps, \
.sta_disconnected_pm = WIFI_STA_DISCONNECTED_PM_ENABLED, \
.magic = WIFI_INIT_CONFIG_MAGIC\
};函数 esp_wifi_init
- esp_err_t esp_wifi_init(wifi_init_config_t *config)
- 为 WiFi 驱动初始化 WiFi 分配资源，如 WiFi 控制结构、RX/TX 缓冲区、WiFi NVS 结构等，这个 WiFi 也启动 WiFi 任务。
- 必须先调用此 API，然后才能调用所有其他 WiFi API。
- 推荐使用 WIFI_INIT_CONFIG_DEFAULT 宏将配置初始化为默认值。
- wifi_init_config_t
- WIFI 初始化结构体。传递给
esp_wifi_init 调用的 WiFi 堆栈配置参数。
typedef struct {
system_event_handler_t event_handler; /**< WiFi event handler */
wifi_osi_funcs_t* osi_funcs; /**< WiFi OS functions */
wpa_crypto_funcs_t wpa_crypto_funcs; /**< WiFi station crypto functions when connect */
int static_rx_buf_num; /**< WiFi static RX buffer number */
int dynamic_rx_buf_num; /**< WiFi dynamic RX buffer number */
int tx_buf_type; /**< WiFi TX buffer type */
int static_tx_buf_num; /**< WiFi static TX buffer number */
int dynamic_tx_buf_num; /**< WiFi dynamic TX buffer number */
int cache_tx_buf_num; /**< WiFi TX cache buffer number */
int csi_enable; /**< WiFi channel state information enable flag */
int ampdu_rx_enable; /**< WiFi AMPDU RX feature enable flag */
int ampdu_tx_enable; /**< WiFi AMPDU TX feature enable flag */
int amsdu_tx_enable; /**< WiFi AMSDU TX feature enable flag */
int nvs_enable; /**< WiFi NVS flash enable flag */
int nano_enable; /**< Nano option for printf/scan family enable flag */
int rx_ba_win; /**< WiFi Block Ack RX window size */
int wifi_task_core_id; /**< WiFi Task Core ID */
int beacon_max_len; /**< WiFi softAP maximum length of the beacon */
int mgmt_sbuf_num; /**< WiFi management short buffer number, the minimum value is 6, the maximum value is 32 */
uint64_t feature_caps; /**< Enables additional WiFi features and capabilities */
bool sta_disconnected_pm; /**< WiFi Power Management for station at disconnected status */
int magic; /**< WiFi init magic number, it should be the last field */
} wifi_init_config_t;- config
- 结构体指针。指向 WIFI 初始化配置结构体。
- return
- ESP_OK: 成功
- ESP_ERR_WIFI_NO_MEM: 内存不足
- others: esp_err.h
函数esp_wifi_set_mode
- esp_err_t esp_wifi_set_mode(wifi_mode_t mode)
- 设置 WIFI 操作模式。
- 可以设置为 station、soft-AP 或 station + soft-AP 模式，默认为 soft-AP 模式。
- wifi_mode_t
- WIFI 配置模式枚举。
ty
typedef enum {
WIFI_MODE_NULL = 0, /**< null mode */
WIFI_MODE_STA, /**< WiFi station mode */
WIFI_MODE_AP, /**< WiFi soft-AP mode */
WIFI_MODE_APSTA, /**< WiFi station + soft-AP mode */
WIFI_MODE_MAX
} wifi_mode_t;- mode
- WIFI 操作模式。
- return
- ESP_OK: 成功
- ESP_ERR_WIFI_NOT_INT: WIFI 未由
esp_wifi_init 初始化
- ESP_ERR_WIFI_ARG: 无效的参数
- other: esp_err.h
函数esp_wifi_set_config
- esp_err_t esp_wifi_set_config(wifi_interface_t interface, wifi_config_t *conf)
- 设置 ESP32 STA 或 AP 的配置。
- 该 API 只有在指定接口开启时才能调用，否则 API 失败。
- ESP32 仅限于一个通道，因此在 soft-AP + station 模式下，soft-AP 会自动调整其通道与 station 的通道相同。
- wifi_interface_t
- 指定接口枚举。
- 该 API 只有在指定接口开启时才能调用，否则 API 失败
typedef enum {
WIFI_IF_STA = ESP_IF_WIFI_STA,
WIFI_IF_AP = ESP_IF_WIFI_AP,
} wifi_interface_t;- interface
- 接口
- wifi_config_t
- WIFI 配置。
- 账号、密码等。
typedef union {
wifi_ap_config_t ap; /**< configuration of AP */
wifi_sta_config_t sta; /**< configuration of STA */
} wifi_config_t;- wifi_ap_config_t
- soft-AP 模式配置结构体。
typedef struct {
uint8_t ssid[32]; /**< SSID of ESP32 soft-AP. If ssid_len field is 0, this must be a Null terminated string. Otherwise, length is set according to ssid_len. */
uint8_t password[64]; /**< Password of ESP32 soft-AP. */
uint8_t ssid_len; /**< Optional length of SSID field. */
uint8_t channel; /**< Channel of ESP32 soft-AP */
wifi_auth_mode_t authmode; /**< Auth mode of ESP32 soft-AP. Do not support AUTH_WEP in soft-AP mode */
uint8_t ssid_hidden; /**< Broadcast SSID or not, default 0, broadcast the SSID */
uint8_t max_connection; /**< Max number of stations allowed to connect in, default 4, max 10 */
uint16_t beacon_interval; /**< Beacon interval which should be multiples of 100. Unit: TU(time unit, 1 TU = 1024 us). Range: 100 ~ 60000. Default value: 100 */
wifi_cipher_type_t pairwise_cipher; /**< pairwise cipher of SoftAP, group cipher will be derived using this. cipher values are valid starting from WIFI_CIPHER_TYPE_TKIP, enum values before that will be considered as invalid and default cipher suites(TKIP+CCMP) will be used. Valid cipher suites in softAP mode are WIFI_CIPHER_TYPE_TKIP, WIFI_CIPHER_TYPE_CCMP and WIFI_CIPHER_TYPE_TKIP_CCMP. */
bool ftm_responder; /**< Enable FTM Responder mode */
} wifi_ap_config_t;- wifi_sta_config_t
- station 模式配置结构体。
typedef struct {
uint8_t ssid[32]; /**< SSID of target AP. */
uint8_t password[64]; /**< Password of target AP. */
wifi_scan_method_t scan_method; /**< do all channel scan or fast scan */
bool bssid_set; /**< whether set MAC address of target AP or not. Generally, station_config.bssid_set needs to be 0; and it needs to be 1 only when users need to check the MAC address of the AP.*/
uint8_t bssid[6]; /**< MAC address of target AP*/
uint8_t channel; /**< channel of target AP. Set to 1~13 to scan starting from the specified channel before connecting to AP. If the channel of AP is unknown, set it to 0.*/
uint16_t listen_interval; /**< Listen interval for ESP32 station to receive beacon when WIFI_PS_MAX_MODEM is set. Units: AP beacon intervals. Defaults to 3 if set to 0. */
wifi_sort_method_t sort_method; /**< sort the connect AP in the list by rssi or security mode */
wifi_scan_threshold_t threshold; /**< When sort_method is set, only APs which have an auth mode that is more secure than the selected auth mode and a signal stronger than the minimum RSSI will be used. */
wifi_pmf_config_t pmf_cfg; /**< Configuration for Protected Management Frame. Will be advertized in RSN Capabilities in RSN IE. */
uint32_t rm_enabled:1; /**< Whether Radio Measurements are enabled for the connection */
uint32_t btm_enabled:1; /**< Whether BSS Transition Management is enabled for the connection */
uint32_t reserved:30; /**< Reserved for future feature set */
} wifi_sta_config_t;- conf
- 结构体指针。指向 wifi_config_t WIFI 配置结构体。
- return
- ESP_OK: 成功
- ESP_ERR_WIFI_NOT_INIT: WIFI 没有被 esp_wifi_init 初始化
- ESP_ERR_INVALID_ARG: 无效的参数
- ESP_ERR_WIFI_IF: 无效的接口
- ESP_ERR_WIFI_MODE: 无效的模式
- ESP_ERR_WIFI_PASSWORD: 无效的密码
- ESP_ERR_WIFI_NVS: WIFI 内部 NVS 错误
- other: esp_err.h
函数esp_wifi_start
- esp_err_t esp_wifi_start(void)
- 根据当前配置启动 WIFI。
- 如果为 WIFI_MODE_STA 模式，则创建 station 控制块并启动 station。
- 如果为 WIFI_MODE_AP 模式，则创建 soft-AP 控制块并启动 soft-AP。
- 如果为 WIFI_MODE_APSTA 模式，则创建 soft-AP 和 station 控制块并启动 soft-AP 和 station。
- return
- ESP_OK: 成功
- ESP_ERR_WIFI_NOT_INIT: WIFI 没有被 esp_wifi_init 初始化
- ESP_ERR_INVALID_ARG: 无效的参数
- ESP_ERR_NO_MEM: 内存不足
- ESP_ERR_WIFI_CONN: WIFI 内部错误、station 或 soft-AP控制块错误
- other: esp_err.h
配网存储并清除配网信息接口
如果使用 esp_wifi_set_config 在恢复出厂设置时不知如何擦除flash 因为flash中保存有SN。
t
typedef enum {
wifi_unconfiged = 0,
wifi_configed = 0xAA,
}wifi_info_storage_t;
#define ID_AND_PWD_LEN (32+64)
/**********************************************
* *函数名：clearWifiConfigFlag
* *功能描述：清除配网标记，如果运行这个函数，可以配合esp_restart(),复位系统。重新配网
* * -- 主要是取代nvs_flash_erase()函数，这个函数把所有的数据都擦除，是不对的。
* *******************************************/
void clearWifiConfigFlag(void)
{
nvs_handle my_handle;
// 0.打开
nvs_open("WIFI_CONFIG", NVS_READWRITE, &my_handle);
// 1.写入标记 0x00,清除配网标记
nvs_set_u8(my_handle, "WifiConfigFlag", wifi_unconfiged);
// 2.提交 并保存表的内容
ESP_ERROR_CHECK(nvs_commit(my_handle));
// 3.关闭nvs退出
nvs_close(my_handle);
}
//保存wifi配置参数结构体变量wifi_config到nvs
static void saveWifiConfig(wifi_config_t *wifi_config)
{
nvs_handle my_handle;
// 0.打开
nvs_open("WIFI_CONFIG", NVS_READWRITE, &my_handle);
// 1.写入标记 0xaa,表示已经配过网
nvs_set_u8(my_handle, "WifiConfigFlag", wifi_configed);
// 2.写入AP ID和AP password
ESP_ERROR_CHECK(nvs_set_blob(my_handle, "wifi_config", wifi_config, ID_AND_PWD_LEN));
// 3.提交 并保存表的内容
ESP_ERROR_CHECK(nvs_commit(my_handle));
// 4.关闭nvs退出
nvs_close(my_handle);
}
//从nvs中读取wifi配置到给定的sta_config结构体变量
static esp_err_t readWifiConfig(wifi_config_t *sta_config)
{
nvs_handle my_handle;
unsigned char u8WifiConfigVal;
// 0.打开
nvs_open("WIFI_CONFIG", NVS_READWRITE, &my_handle);
// 1.读取标志位，并判断
nvs_get_u8(my_handle, "WifiConfigFlag", &u8WifiConfigVal);
if(u8WifiConfigVal != wifi_configed){
// 1.1 没有配过网，关闭nvs，返回错误码
ESP_LOGI(TAG, "no wifi config,read fail!");
nvs_close(my_handle);
return ESP_FAIL;
}else{
// 1.2 进入下个步骤
ESP_LOGI(TAG, "wifi configed ,read ok!");
}
// 2.读取上一次配网的ID，password
uint32_t len = ID_AND_PWD_LEN;
esp_err_t err = nvs_get_blob(my_handle, "wifi_config", sta_config, &len);
ESP_LOGI(TAG, "readout SSID:%s", sta_config->sta.ssid);
ESP_LOGI(TAG, "readout PASSWORD:%s", sta_config->sta.password);
// 3.关闭nvs退出
nvs_close(my_handle);
return err;
}ESP获取连接的WiFi信号强度
通过WiFi扫描接口过滤出连接的WiFi信息
wifi_sta_record* get_rssi(void)
{
uint16_t number = 1;
uint16_t ap_count = 0;
wifi_sta_record* sta_record = (wifi_sta_record*) malloc (sizeof(wifi_sta_record));
wifi_ap_record_t ap_info[1];
wifi_config_t wifi_sta_cfg;
BLUFI_INFO("start scan");
memset(ap_info, 0, sizeof(ap_info));
if (esp_wifi_get_config(WIFI_IF_STA, &wifi_sta_cfg) != ESP_OK)//获取已连接的ap参数
{
BLUFI_ERROR("esp_wifi_get_config err");
return NULL;
}
wifi_scan_config_t scan_config = { 0 };
scan_config.ssid = wifi_sta_cfg.sta.ssid;//限制扫描的ap的ssid
strcpy((char *)sta_record->ssid, (char*)wifi_sta_cfg.sta.ssid);
scan_config.bssid = wifi_sta_cfg.sta.bssid;//限制扫描的ap的mac地址
esp_wifi_scan_start(&scan_config, true);//阻塞扫描ap，scan_config为扫描的参数
ESP_ERROR_CHECK(esp_wifi_scan_get_ap_records(&number, ap_info));//获取扫描到的ap信息
ESP_ERROR_CHECK(esp_wifi_scan_get_ap_num(&ap_count));
//获取扫描到的ap数量，因为限制了ssid和mac，因此最多只会扫描到1个
for (int i = 0; (i < 1) && (i < ap_count); i++) {
BLUFI_INFO("SSID \t\t%s", ap_info[i].ssid);
BLUFI_INFO("RSSI \t\t%d", ap_info[i].rssi);
ESP_LOGI(TAG, "Channel \t\t%d", ap_info[i].primary);
ESP_LOGI(TAG, "BSSID: \t\t%02x:%02x:%02x:%02x:%02x:%02x",
ap_info[i].bssid[0],
ap_info[i].bssid[1],
ap_info[i].bssid[2],
ap_info[i].bssid[3],
ap_info[i].bssid[4],
ap_info[i].bssid[5]);
}
esp_wifi_scan_stop();
//from start to stop need 3210ms
BLUFI_INFO("stop scan\r\n");
sta_record->rssi = ap_info[0].rssi;
return sta_record;
}
//测试使用
wifi_sta_record* sta_info;
sta_info = get_rssi();
BLUFI_INFO("blufi sta signal strength ssid:%s, rssi:%d ",sta_info->ssid,sta_info->rssi );方法二：直接使用乐鑫封好的API：esp_wifi_sta_get_ap_info
wifi_sta_record* get_rssi(void)
{
wifi_sta_record* sta_record = (wifi_sta_record*) malloc (sizeof(wifi_sta_record));
wifi_ap_record_t ap_info[1];
memset(ap_info, 0, sizeof(ap_info));
//获取当前连接的WiFi信息
if (esp_wifi_sta_get_ap_info(ap_info)!= ESP_OK)
{
BLUFI_ERROR("esp_wifi_sta_ap_info err");
return sta_record;
}
strcpy((char *)sta_record->ssid, (char*)ap_info[0].ssid);
sta_record->rssi = ap_info[0].rssi;
return sta_record;
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