esp_wifi_connect() while running in WIFI_MODE_APSTA causes access point to close
Posted: Wed Feb 15, 2017 5:44 pm
Hi
I'm running my ESP32 in simultaneous access point mode and station mode.
The idea is that a user can connect to the devices access point, and from a web interface select which access point the esp should connect to.
However, i have problems when running esp_wifi_connect() while hosting an access point. When the esp tries to connect, it will at the same time temporarily stop hosting its own access point. Is this expected behaviour and is there something which could be done to work around this issue? The access point works correctly if the esp is successfully connected as a station or if it does not attempt to connect.
It should be possible to mitigate the issue somewhat by not trying to reconnect immediately after a failed attempt. This is however suboptimal.
The relevant code is listed below
I'm running my ESP32 in simultaneous access point mode and station mode.
The idea is that a user can connect to the devices access point, and from a web interface select which access point the esp should connect to.
However, i have problems when running esp_wifi_connect() while hosting an access point. When the esp tries to connect, it will at the same time temporarily stop hosting its own access point. Is this expected behaviour and is there something which could be done to work around this issue? The access point works correctly if the esp is successfully connected as a station or if it does not attempt to connect.
It should be possible to mitigate the issue somewhat by not trying to reconnect immediately after a failed attempt. This is however suboptimal.
The relevant code is listed below
Code: Select all
void WifiHandler::initialise_wifi(void)
{
tcpip_adapter_init();
WifiHandler::wifi_event_group = xEventGroupCreate();
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) );
ESP_ERROR_CHECK( esp_wifi_set_storage(WIFI_STORAGE_RAM) );
//Set up wifi access point configuration
wifi_config_t ap_config;
uint8_t ap_ssid[32] = "ESP32_AP\0";
uint8_t ap_pass[64] = "\0";
memcpy(ap_config.ap.ssid, ap_ssid, 32);
memcpy(ap_config.ap.password, ap_pass, 64);
ap_config.ap.ssid_len = 0; //ONLY USED IF NOT 0 teminated.
ap_config.ap.authmode = WIFI_AUTH_OPEN;
ap_config.ap.ssid_hidden = 0;
ap_config.ap.max_connection = 20;
ap_config.ap.beacon_interval = 100;
ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_APSTA) ); //Configure as both accesspoint and station
ESP_ERROR_CHECK( esp_wifi_set_config(WIFI_IF_AP, &ap_config));
this->update_station_config();
ESP_ERROR_CHECK( esp_wifi_start() );
}
Code: Select all
void WifiHandler::update_station_config()
{
//Set up wifi station configuration.
wifi_config_t wifi_config = {
.sta = {
"",
"",
false,
"",
},
};
//Retrieve setting from NVS
size_t len_passwd = 64;
size_t len_ssid = 32;
esp_err_t err = s_handler->nvs_get("STA_SSID", (char *)wifi_config.sta.ssid, &len_ssid);
printf("%d\n", err);
err = s_handler->nvs_get("STA_PASSWORD", (char *)wifi_config.sta.password, &len_passwd);
printf("%d\n", err);
ESP_LOGI(TAG, "Setting WiFi configuration SSID %s...", wifi_config.sta.ssid);
ESP_ERROR_CHECK( esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
//ESP_ERROR_CHECK( esp_wifi_set_auto_connect(true) );
ESP_ERROR_CHECK( esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
}
Code: Select all
esp_err_t WifiHandler::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:
xEventGroupSetBits(WifiHandler::wifi_event_group, CONNECTED_BIT);
break;
case SYSTEM_EVENT_STA_DISCONNECTED:
/* This is a workaround as ESP32 WiFi libs don't currently
auto-reassociate. */
esp_wifi_connect();
xEventGroupClearBits(WifiHandler::wifi_event_group, CONNECTED_BIT);
break;
case SYSTEM_EVENT_AP_STACONNECTED:
printf("station connected to access point. Now listing connected stations!\n");
wifi_sta_list_t sta_list;
ESP_ERROR_CHECK( esp_wifi_ap_get_sta_list(&sta_list));
for(int i = 0; i < sta_list.num; i++)
{
//Print the mac address of the connected station
wifi_sta_info_t &sta = sta_list.sta[i];
printf("Station %d MAC: %02X:%02X:%02X:%02X:%02X:%02X\n", i,
sta.mac[0], sta.mac[1], sta.mac[2], sta.mac[3], sta.mac[4], sta.mac[5]);
}
default:
break;
}
return ESP_OK;
}