Other Arduino Codes and Videos by Robojax

Using ESP8266 WiFi Scan check WiFi AP and signal strength in percentage with Arduino

Using ESP8266 WiFi Scan to see all available WiFi AP with Arduino

This code is to use ESP8266, NodeMCU, Wemos D1 Mini to diplay all available access points (WiFi ) on serial monitor. In this page I have provided 3 different Arduiono codes:
1-Basic WiFi scan
2-Display Open WiFo only
3-Advanced WiFi scan

Resources for this sketch

Basic WiFi scan code


 
 /*
 * WiRi Signal strenght in Percentage (RSSI) calculation 
 * works with any ESP8266 MCU such as Di Mini, D1 Mini Pro, D1, NodeMCU or any other ESP8166 MCU
 * and display on Serial Monitor
 * 
 * Written by Ahmad Shamshiri 
 * on Aug 10, 2019 at 18:08 in Ajax, Ontario, Canada

watch video instruction for this code: https://youtu.be/EbqIB9vJbsQ

Get this code and other Arduino codes from Robojax.com
Learn Arduino step by step in structured course with all material, wiring diagram and library
all in once place. Purchase My course on Udemy.com http://robojax.com/L/?id=62

If you found this tutorial helpful, please support me so I can continue creating 
content like this. You can support me on Patreon http://robojax.com/L/?id=63

or make donation using PayPal http://robojax.com/L/?id=64


 * 
  * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include "ESP8266WiFi.h"

const int RSSI_MAX =-50;// define maximum strength of signal in dBm
const int RSSI_MIN =-100;// define minimum strength of signal in dBm

const int displayEnc=1;// set to 1 to display Encryption or 0 not to display

void setup() {
  Serial.begin(115200);
  Serial.println("Robojax Wifi Signal Scan");
  // Set WiFi to station mode and disconnect from an AP if it was previously connected
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(2000);

  Serial.println("Setup done");
}

void loop() {
  Serial.println("Wifi scan started");

  // WiFi.scanNetworks will return the number of networks found
  int n = WiFi.scanNetworks();
  Serial.println("Wifi scan ended");
  if (n == 0) {
    Serial.println("no networks found");
  } else {
    Serial.print(n);
    Serial.println(" networks found");
    for (int i = 0; i < n; ++i) {
      // Print SSID and RSSI for each network found
      Serial.print(i + 1);
      Serial.print(") ");
      Serial.print(WiFi.SSID(i));// SSID

                  
      Serial.print(WiFi.RSSI(i));//Signal strength in dBm  
      Serial.print("dBm (");

      
      Serial.print(dBmtoPercentage(WiFi.RSSI(i)));//Signal strength in %  
     Serial.print("% )"); 
      if(WiFi.encryptionType(i) == ENC_TYPE_NONE)
      {
          Serial.println(" <<***OPEN***>>");        
      }else{
          Serial.println();        
      }

      delay(10);
    }
  }
  Serial.println("");

  // Wait a bit before scanning again
  delay(5000);
  WiFi.scanDelete();  
}// loop



/*
 * Written by Ahmad Shamshiri
  * with lots of research, this sources was used:
 * https://support.randomsolutions.nl/827069-Best-dBm-Values-for-Wifi 
 * This is approximate percentage calculation of RSSI
 * WiFi Signal Strength Calculation
 * Written Aug 08, 2019 at 21:45 in Ajax, Ontario, Canada
 */

int dBmtoPercentage(int dBm)
{
  int quality;
    if(dBm <= RSSI_MIN)
    {
        quality = 0;
    }
    else if(dBm >= RSSI_MAX)
    {  
        quality = 100;
    }
    else
    {
        quality = 2 * (dBm + 100);
   }

     return quality;
}//dBmtoPercentage   

Open WiFi scan code

Displays only Access Points that have no password


 
 /*
 * Using ESP8166 Di Mini, NodeMCU to display only Open WiFi Networks
 * and display on Serial Monitor
 * 
 * Written by Ahmad Shamshiri 
 * on Aug 08, 2019 at 21:45 in Ajax, Ontario, Canada

watch video instruction for this code:

Get this code and other Arduino codes from Robojax.com
Learn Arduino step by step in structured course with all material, wiring diagram and library
all in once place. Purchase My course on Udemy.com http://robojax.com/L/?id=62

If you found this tutorial helpful, please support me so I can continue creating 
content like this. You can support me on Patreon http://robojax.com/L/?id=63

or make donation using PayPal http://robojax.com/L/?id=64


 * 
  * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include "ESP8266WiFi.h"

const int RSSI_MAX =-50;// define maximum straighten of signal in dBm
const int RSSI_MIN =-100;// define minimum strength of signal in dBm


int openNetworkCount=0;// do not change. used inside loop

void setup() {
  Serial.begin(115200);
  Serial.println("Robojax Wifi Signal Scan");
  // Set WiFi to station mode and disconnect from an AP if it was previously connected
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(2000);

  Serial.println("Setup done");
}

void loop() {
  Serial.println("Wifi scan started");

  // WiFi.scanNetworks will return the number of networks found
  int n = WiFi.scanNetworks();
  Serial.println("Wifi scan ended");
  if (n == 0) {
    Serial.println("no networks found");
  } else {
    Serial.print(n);
    Serial.println(" networks found");
    for (int i = 0; i < n; ++i) {
      // Print SSID and RSSI for each network found
      if(WiFi.encryptionType(i) == ENC_TYPE_NONE)
      {
      openNetworkCount++;
      Serial.print(openNetworkCount);
      Serial.print(") ");
      Serial.print(WiFi.SSID(i));// SSID
      
                  
      Serial.print(WiFi.RSSI(i));//Signal strength in dBm  
      Serial.print("dBm (");

      
      Serial.print(dBmtoPercentage(WiFi.RSSI(i)));//Signal strength in %  
      Serial.print("% )");
      }// if 


      delay(10);
    }
  }
  Serial.println("");

  // Wait a bit before scanning again
  delay(5000);
  WiFi.scanDelete();  
openNetworkCount =0;//reset open network counts  
}// loop



/*
 * Written by Ahmad Shamshiri
  * with lots of research, this sources was used:
 * https://support.randomsolutions.nl/827069-Best-dBm-Values-for-Wifi 
 * This is approximate percentage calculation of RSSI
 * Wifi Signal Strength Calculation
 * Written Aug 08, 2019 at 21:45 in Ajax, Ontario, Canada
 */

int dBmtoPercentage(int dBm)
{
  int quality;
    if(dBm <= RSSI_MIN)
    {
        quality = 0;
    }
    else if(dBm >= RSSI_MAX)
    {  
        quality = 100;
    }
    else
    {
        quality = 2 * (dBm + 100);
   }

     return quality;
}//dBmtoPercentage   

Advanced WiFi scan code

Displays the following:


 
 /*
 * WiFi Scan Advanced Code to display more information
 * about the WiFi network.
 * This Arduino code will work any module 
 * that has ESP8266 such as NodeMCU, D1, D1 Mini, D1 Mini pro etc.
 * 
 * Written by Ahmad Shamshiri 
 * on Aug 08, 2019 at 21:45 in Ajax, Ontario, Canada

watch video instruction for this code:

Get this code and other Arduino codes from Robojax.com
Learn Arduino step by step in structured course with all material, wiring diagram and library
all in once place. Purchase My course on Udemy.com http://robojax.com/L/?id=62

If you found this tutorial helpful, please support me so I can continue creating 
content like this. You can support me on Patreon http://robojax.com/L/?id=63

or make donation using PayPal http://robojax.com/L/?id=64


 * 
  * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include "ESP8266WiFi.h"

const int RSSI_MAX =-50;// define maximum strength of signal in dBm
const int RSSI_MIN =-100;// define minimum strength of signal in dBm

const int displayEnc=1;// set to 1 to dispaly Encryption or 0 not to display

void setup() {
  Serial.begin(115200);
  Serial.println("Robojax Wifi Signal Scan");
  // Set WiFi to station mode and disconnect from an AP if it was previously connected
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(2000);

  Serial.println("Setup done");
}

void loop() {
  Serial.println("Wifi scan started");

  // WiFi.scanNetworks will return the number of networks found
  int n = WiFi.scanNetworks();
  Serial.println("Wifi scan ended");
  if (n == 0) {
    Serial.println("no networks found");
  } else {
    Serial.print(n);
    Serial.println(" networks found");
    for (int i = 0; i < n; ++i) {
      // Print SSID and RSSI for each network found
      Serial.print(i + 1);
      Serial.print(") ");
      Serial.print(WiFi.SSID(i));// SSID
      
      Serial.print(" ch:");  
      Serial.print(WiFi.channel(i));// display channel
      Serial.print(" ");     
                  
      Serial.print(WiFi.RSSI(i));//Signal strength in dBm  
      Serial.print("dBm (");

      
      Serial.print(dBmtoPercentage(WiFi.RSSI(i)));//Signal strength in %  
      Serial.print("% )");

      Serial.print(" MAC:");
      Serial.print(WiFi.BSSIDstr(i)  );//MAC address  (Basic Service Set Identification) 
            
    
      if(WiFi.isHidden(i) ){
       Serial.print(" <<Hidden>> ");           
      }
     if(displayEnc)
     {
        Serial.print(" Encryption:");      
        Serial.println(encType(i));    
      }// if displayEnc    

      delay(10);
    }
  }
  Serial.println("");

  // Wait a bit before scanning again
  delay(5000);
  WiFi.scanDelete();  
}// loop


/*
 * @brief returns the encryption type as String
 * @param "id" network ID integer
 * @return String text of network type
 *    Usage: encType(i)
 *    //where i is id of scanned network
 * Written by Ahmad Shamshiri on August 10, 2019 at 17:33
 * in Ajax, Ontario, Canada
 * www.Robojax.com 
 */
 
String encType(int id){

String type;
  if(WiFi.encryptionType(id) == ENC_TYPE_WEP){
    type=" WEP";
  }else if(WiFi.encryptionType(id) == ENC_TYPE_TKIP){
    type="WPA / PSK";    
  }else if(WiFi.encryptionType(id) == ENC_TYPE_CCMP){
    type="WPA2 / PSK";    
  }else if(WiFi.encryptionType(id) == ENC_TYPE_AUTO){
    type="WPA / WPA2 / PSK";    
  }else if(WiFi.encryptionType(id) == ENC_TYPE_NONE){
    type="<<OPEN>>";    
  }
  return type;
//1:  ENC_TYPE_WEP – WEP
//2 : ENC_TYPE_TKIP – WPA / PSK
//4 : ENC_TYPE_CCMP – WPA2 / PSK
//7 : ENC_TYPE_NONE – open network
//8 : ENC_TYPE_AUTO – WPA / WPA2 / PSK
}

/*
 * Written by Ahmad Shamshiri
  * with lots of research, this sources was used:
 * https://support.randomsolutions.nl/827069-Best-dBm-Values-for-Wifi 
 * This is approximate percentage calculation of RSSI
 * Wifi Signal Strength Calculation
 * Written Aug 08, 2019 at 21:45 in Ajax, Ontario, Canada
 */

int dBmtoPercentage(int dBm)
{
  int quality;
    if(dBm <= RSSI_MIN)
    {
        quality = 0;
    }
    else if(dBm >= RSSI_MAX)
    {  
        quality = 100;
    }
    else
    {
        quality = 2 * (dBm + 100);
   }

     return quality;
}//dBmtoPercentage   

If you found this tutorial helpful, please support me so I can continue creating content like this. You can support me on Patreon ( Launched June 14, 2019): http://bit.ly/2ZnITLz

Or support me via PayPal