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
- Introduction Wemos NodeMCU
- Robojax Arduino Course on Udemy
- Get Early Access to my videos via Patreon
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:
- SSID
- Channel
- Signal Strength in dBm
- Signal Strength in Percentage
- MAC address
- Encryption Type
- Hidden or not
/*
* 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