WiFi.SSID returning null or empty using esp_wifi_sta_get_ap_info

[megazero1316]

Hardware:

Board: ESP32 Dev Module
Core Installation/update date: 30/jul/2018
IDE name: Arduino IDE
Flash Frequency: 40Mhz
Upload Speed: 92600

Description:

As far as i know that if esp32 connected to a wifi it store the configuration in the flash but calling WiFi.SSID() return null after restarting esp32, what i notice is that the SSID is called from esp_wifi_sta_get_ap_info while the psk is called esp_wifi_get_config in WiFiSTA.cpp
the way i solved this problem is i copied the code in WiFi.psk() and added to WiFi.SSID() like this :

String WiFiSTAClass::SSID() const
{
    if(WiFiGenericClass::getMode() == WIFI_MODE_NULL){
        return String();
    }
    wifi_ap_record_t info;
    if(!esp_wifi_sta_get_ap_info(&info)) {
        return String(reinterpret_cast<char*>(info.ssid));
    }
    else{
          wifi_config_t conf;
          esp_wifi_get_config(WIFI_IF_STA, &conf);
          return String(reinterpret_cast<char*>(conf.sta.ssid));    
    }

    return String();
}

and everything went good for me , is this consider a good solution for this problem ? as i was looking for others solutions but couldn`t find

Sketch:

#include <WiFi.h>
/*commented after 1st time connection*/
//const char* ssid     = "your-ssid";
//const char* password = "your-password";



void setup()
{
    Serial.begin(115200);
    delay(10);
    WiFi.mode(WIFI_STA);
    WiFi.persistent (true);
    // We start by connecting to a WiFi network

    Serial.println();
    Serial.println();
    Serial.print("Connecting to ");
    Serial.println(ssid);

    WiFi.begin(ssid, password);

    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }

    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
}



void loop()
{
    
}

[javiercuellar73]

Great solution!!!!
This should be add to next version.

[lbernstone]

You can also extract this directly from nvs.

#include <nvs_flash.h>
#include <nvs.h>

const char* get_ssid() {
  nvs_handle hndl;
  nvs_open("nvs.net80211", NVS_READONLY, &hndl);
  size_t ssid_len = 36;
  char ssid[ssid_len];
  esp_err_t err = nvs_get_blob(hndl, "sta.ssid", ssid, &ssid_len);
  String ssid_str;
  if (err == ESP_OK) 
    for(char x : ssid) 
      if (x>32) ssid_str += x;
  return ssid_str.c_str();
}

void setup() {
  Serial.begin(115200);
  nvs_flash_init();
  Serial.println(get_ssid());
}

void loop() {}

[johnty]

just another ping on this: ran into this issue recently. @megazero1316's solution appears to work great. any idea why it hasn't been merged in yet?

[huexpub]

yes, is good solution

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[everslick]

https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/network/esp_wifi.html#_CPPv424esp_wifi_sta_get_ap_infoP16wifi_ap_record_t

looks like a bug in IDF. commenting here to stop stale[bot] from closing this issue.

[stale]

[STALE_SET] This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[everslick]

@me-no-dev : is WiFiSTAClass::SSID() supposed to return the SSID that is configured or the one that it is connected to?

[stale]

[STALE_CLR] This issue has been removed from the stale queue. Please ensure activity to keep it openin the future.

[me-no-dev]

it grabs the configuration so I imagine it's the one configured.

[everslick]

no, the original code does not:

https://github.com/espressif/arduino-esp32/blob/master/libraries/WiFi/src/WiFiSTA.cpp#L547

it grabs info.

I think IDF works as designed. it should not return an SSID if not currently connected. Question is, what does a Arduino user expect? Should we return the configured SSID if not connected?

[me-no-dev]

this is a good question... maybe we should

[stale]

[STALE_SET] This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[stale]

[STALE_DEL] This stale issue has been automatically closed. Thank you for your contributions.