ESP32WifiSmartConfig.ino

#include "FS.h"
#include "esp_system.h"
#include <esp_wifi.h>
#include <string.h>
#include <WiFi.h>
#include <Preferences.h>  // WiFi storage

const  char* rssiSSID;       // NO MORE hard coded set AP, all SmartConfig
const  char* password;
String PrefSSID, PrefPassword;  // used by preferences storage

int  WFstatus;
int UpCount = 0;
int32_t rssi;           // store WiFi signal strength here
String getSsid;
String getPass;
String  MAC;

// For SSID storage
Preferences preferences;  // declare class object
  
void setup() {
  Serial.begin(115200);
  Serial.printf("\tWiFi Setup -- \n"  ); 

  wifiInit();       // get WiFi connected
  IP_info();
  MAC = getMacAddress();

  //delay(2000);
} //  END setup()
  
void loop()
{
  if ( WiFi.status() ==  WL_CONNECTED )      // Main connected loop

  { 
    // ANY MAIN LOOP CODE HERE

  }   // END Main connected loop()
  else  // WiFi DOWN
  {            
     WFstatus = getWifiStatus( WFstatus );
     WiFi.begin( PrefSSID.c_str() , PrefPassword.c_str() );
     int WLcount = 0;
     while (WiFi.status() != WL_CONNECTED && WLcount < 200 )
     {
        delay( 100 );
        Serial.printf(".");
  
        if (UpCount >= 60)  // keep from scrolling sideways forever
        {
           UpCount = 0;
           Serial.printf("\n");
        }
        ++UpCount;
        ++WLcount;
     }

    /*if( getWifiStatus( WFstatus ) == 3 )   //wifi returns
    { 
    // stop LED flasher, wifi going up
    }*/

    if( getWifiStatus( WFstatus ) == 1 )   //wifi returns
    { 
      initSmartConfig();
    }
    
    delay( 1000 );
  }  // END WiFi down 
} // END loop()
  
void wifiInit()  // 
{
   WiFi.mode(WIFI_AP_STA);   // required to read NVR before WiFi.begin()

   // load credentials from NVR, a little RTOS code here
   wifi_config_t conf;
   esp_wifi_get_config(WIFI_IF_STA, &conf);  // load wifi settings to struct comf
   rssiSSID = reinterpret_cast<const char*>(conf.sta.ssid);
   password = reinterpret_cast<const char*>(conf.sta.password);

   // Open Preferences with "wifi" namespace. Namespace is limited to 15 chars
   preferences.begin("wifi", false);
       PrefSSID  =  preferences.getString("ssid", "none");          //NVS key ssid
       PrefPassword  =  preferences.getString("password", "none");  //NVS key password
   preferences.end();

   // keep from rewriting flash if not needed
   if( !checkPrefsStore() )     // see is NV and Prefs are the same
   {              // not the same, setup with SmartConfig
      if( PrefSSID == "none" )  // New...setup wifi
      {
        initSmartConfig(); 
        delay(3000);
        ESP.restart();   // reboot with wifi configured
      }
   } 

   // I flash LEDs while connecting here

   WiFi.begin( PrefSSID.c_str() , PrefPassword.c_str() );

   int WLcount = 0;
   while (WiFi.status() != WL_CONNECTED && WLcount < 200 ) // can take > 100 loops depending on router settings
   {
     delay( 100 );
     Serial.printf(".");
     ++WLcount;
   }
  delay( 3000 );

  //  stop the led flasher here

  }  // END wifiInit()

// match WiFi IDs in NVS to Pref store,  assumes WiFi.mode(WIFI_AP_STA);  was executed
bool checkPrefsStore()   
{
    bool val = false;
    String NVssid, NVpass, prefssid, prefpass;

    NVssid = getSsidPass( "ssid" );
    NVpass = getSsidPass( "pass" );

    // Open Preferences with my-app namespace. Namespace name is limited to 15 chars
    preferences.begin("wifi", false);
        prefssid  =  preferences.getString("ssid", "none");     //NVS key ssid
        prefpass  =  preferences.getString("password", "none"); //NVS key password
    preferences.end();

    if( NVssid.equals(prefssid) && NVpass.equals(prefpass) )
      { val = true; }

  return val;
}

// optionally call this function any way you want in your own code
// to remap WiFi to another AP using SmartConfig mode.   Button, condition etc.. 
void initSmartConfig() 
{
   // start LED flasher
  int loopCounter = 0;

  WiFi.mode( WIFI_AP_STA );       //Init WiFi, start SmartConfig
  Serial.printf( "Entering SmartConfig\n" );

  WiFi.stopSmartConfig(); //Stop previous SmartConfig
  delay(1000);
  WiFi.beginSmartConfig();

  while (!WiFi.smartConfigDone()) 
  {
     // flash led to indicate not configured
          Serial.printf( "." );
     if( loopCounter >= 40 )  // keep from scrolling sideways forever
     {
         loopCounter = 0;
         Serial.printf( "\n" );
     }
     delay(600);
    ++loopCounter;
  }
  loopCounter = 0;

  // stopped flasher here

  Serial.printf("\nSmartConfig received.\n Waiting for WiFi\n\n");
  delay(2000 );
    
  while( WiFi.status() != WL_CONNECTED )      // check till connected
  { 
    delay(500);
  }
  IP_info();  // connected lets see IP info

  preferences.begin("wifi", false);      // put it in storage
     preferences.putString( "ssid"         , getSsid);
     preferences.putString( "password", getPass);
  preferences.end();

    delay(300);
}  // END SmartConfig()

void IP_info()
{
   getSsid = WiFi.SSID();
   getPass = WiFi.psk();
   rssi = getRSSI(  rssiSSID );
   WFstatus = getWifiStatus( WFstatus );
   MAC = getMacAddress();

   Serial.printf( "\n\n\tSSID\t%s, ", getSsid.c_str() );
   Serial.print( rssi);  Serial.printf(" dBm\n" );  // printf??
   Serial.printf( "\tPass:\t %s\n", getPass.c_str() ); 
   Serial.print( "\n\n\tIP address:\t" );  Serial.print(WiFi.localIP() );
   Serial.print( " / " );
   Serial.println( WiFi.subnetMask() );
   Serial.print( "\tGateway IP:\t" );  Serial.println( WiFi.gatewayIP() );
   Serial.print( "\t1st DNS:\t" );     Serial.println( WiFi.dnsIP() );
   Serial.printf( "\tMAC:\t\t%s\n", MAC.c_str() );
}

int getWifiStatus( int WiFiStatus  )
{
  WiFiStatus = WiFi.status();
  Serial.printf("\tStatus %d",  WiFiStatus );
  switch( WiFiStatus )
  {
    case WL_IDLE_STATUS :                         // WL_IDLE_STATUS     = 0,
          Serial.printf(", WiFi IDLE \n");
          break;
    case WL_NO_SSID_AVAIL:                        // WL_NO_SSID_AVAIL   = 1,
          Serial.printf(", NO SSID AVAIL \n");
          break;
    case WL_SCAN_COMPLETED:                       // WL_SCAN_COMPLETED  = 2,
          Serial.printf(", WiFi SCAN_COMPLETED \n");
          break;
    case WL_CONNECTED:                            // WL_CONNECTED       = 3,
          Serial.printf(", WiFi CONNECTED \n");
          break;
    case WL_CONNECT_FAILED:                       // WL_CONNECT_FAILED  = 4,
          Serial.printf(", WiFi WL_CONNECT FAILED\n"); 
          break;
    case WL_CONNECTION_LOST:                      // WL_CONNECTION_LOST = 5,
          Serial.printf(", WiFi CONNECTION LOST\n");
          WiFi.persistent(false);                 // don't write FLASH
          break;
    case WL_DISCONNECTED:                         // WL_DISCONNECTED    = 6
          Serial.printf(", WiFi DISCONNECTED ==\n");
          WiFi.persistent(false);                 // don't write FLASH when reconnecting
          break;
  }
  return WiFiStatus;
}
// END getWifiStatus()

// Get the station interface MAC address.
// @return String MAC
String getMacAddress(void)
{
    WiFi.mode(WIFI_AP_STA);                    // required to read NVR before WiFi.begin()
    uint8_t baseMac[6];
    esp_read_mac( baseMac, ESP_MAC_WIFI_STA ); // Get MAC address for WiFi station
    char macStr[18] = { 0 };
    sprintf(macStr, "%02X:%02X:%02X:%02X:%02X:%02X", baseMac[0], baseMac[1], baseMac[2], baseMac[3], baseMac[4], baseMac[5]);
    return String(macStr);
}
// END getMacAddress()


// Return RSSI or 0 if target SSID not found
// const char* SSID = "YOUR_SSID";  // declare in GLOBAL space
// call:  int32_t rssi = getRSSI( SSID );
int32_t getRSSI( const char* target_ssid ) 
{
  byte available_networks = WiFi.scanNetworks();

  for (int network = 0; network < available_networks; network++) 
  {
    if ( strcmp(  WiFi.SSID( network).c_str(), target_ssid ) == 0) 
    {
      return WiFi.RSSI( network );
    }
  }
  return 0;
} //  END  getRSSI()


// Requires; #include <esp_wifi.h>
// Returns String NONE, ssid or pass arcording to request 
// ie String var = getSsidPass( "pass" );
String getSsidPass( String s )
{
  String val = "NONE";  // return "NONE" if wrong key sent
  s.toUpperCase();
  if( s.compareTo("SSID") == 0 )
  {
     wifi_config_t conf;
     esp_wifi_get_config( WIFI_IF_STA, &conf );
     val = String( reinterpret_cast<const char*>(conf.sta.ssid) );
  }
  if( s.compareTo("PASS") == 0 )
  {
     wifi_config_t conf;
     esp_wifi_get_config( WIFI_IF_STA, &conf );
     val = String( reinterpret_cast<const char*>(conf.sta.password) );
  }
 return val;
}