ESP8266 Manual Wifi Configuration with EEPROM without Hard-Code

In this guide, you will learn about the ESP8266 Manual Wifi Configuration with EEPROM without Hard-Code network certificates. You can learn how to configure WiFi settings on the ESP8266 board, without hard coding and by saving again. Here we will use an EEPROM library that allows you to connect your ESP8266 to various Access Points (APs) without hard-coding and upload new code to your board. ESP8266 WiFi-Manager library is a way to manually configure the wifi but, we will not use it here.

All IoT products in 2020 only work like this. Initially, they all act as hotspots. Then you need to connect your phone or PC to that hotspot. Once the hotspot is connected, then go to the special IP address (192.168.4.1) and then enter the WiFi certificates, and then it is automatically connected to the home router or WiFi. So most IoT devices are built using ESP8266 which helps you set up network configuration (for example SSID, and WiFi router password) through a form and stored in its memory.

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ESP8266 Manual Wifi Configuration with EEPROM

Here we will build an IoT device, using the ESP8266 Manual Wifi Configuration with EEPROM. that will help you set up the network configuration (for example SSID, and the password of the WiFi router) via a form and store it in its EEPROM memory. It’s a little harder to do then the Arduino boards. The ESP8266 doesn’t really have EEPROM like all real Arduino boards do. That’s why most of us struggle to use the EEPROM library with the ESPP66 development board.

You do not have to hard-code your network credentials (SSID and password) using this feature. Your ESP will automatically join known networks or set up access points that you can use to configure network credentials.

How do ESP8266 Manual WiFi Configuration Works?

1. When your ESP8266 boots, it sets up in station mode and tries to connect to a previously saved access point (a known SSID and password combination).
2. If this process fails, it sets ESP to access point mode.
3. Using any WiFi-enabled device with any browser, connect to the newly created AP.
4. After establishing a connection with the newly created access point. You can go to the default IP address 192.168.4.1 to open a web page that allows you to configure your SSID and password.
5. Once the new SSID and password are set the ESP reboots and tries to connect.
6. If it establishes a connection, the process ends successfully. Otherwise, it will be established as an Access Point again.

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What is Access Point?

An access point is a device that creates a wireless local area network. Or WLAN, usually in an office or large building. An access point is sometimes connected to a wired router, switch, or hub via an Ethernet cable, and a Wi-Fi signal project in a specified area. It is used to configure IoT devices for first time users or password changes.

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Program Code Explanation

In this ESP8266 Manual WiFi configuration project, ESP8266 with EEPROM has 3 sections for manual WiFi configuration work. The first one (EEPROM Conundrum), where we will see how to write data in ESP8266 memory.

ESP8266 can be problematic to write values ​​other than integers to memory. The main reason is that the standard EEPROM library does not work because ESP8266 does not have EEPROM. The library we use only emulates EEPROM but in real life, we ​​are writing in flash memory.

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <ESP8266WebServer.h>
#include <EEPROM.h>
 
//Variables
int i = 0;
int statusCode;
const char* ssid = "text";
const char* passphrase = "text";
String st;
String content;
 
 
//Function Decalration
bool testWifi(void);
void launchWeb(void);
void setupAP(void);
 
//Establishing Local server at port 80 whenever required
ESP8266WebServer server(80);

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Everything we write in ESP8266 memory must be striped, and we can write them one letter at a time. First, we declare the string variable st and content and some complete geek and const four *.

We will then announce the following three different actions:

bool testWifi(void);
void launchWeb(void);
void setupAP(void);

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Serial.begin(115200); //Initialising if(DEBUG)Serial Monitor
  Serial.println();
  Serial.println("Disconnecting previously connected WiFi");
  WiFi.disconnect();
  EEPROM.begin(512); //Initialasing EEPROM
  delay(10);
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.println();
  Serial.println();
  Serial.println("Startup");

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In ESP8266 Manual Wifi Configuration with EEPROM without Hard-Code. First, start the EEPROM function with EEPROM.begin. And then also set the storage size. Next cycle through string value.

String esid;
  for (int i = 0; i < 32; ++i)
  {
    esid += char(EEPROM.read(i));
  }
  Serial.println();
  Serial.print("SSID: ");
  Serial.println(esid);
  Serial.println("Reading EEPROM pass");
 
  String epass = "";
  for (int i = 32; i < 96; ++i)
  {
    epass += char(EEPROM.read(i));
  }
  Serial.print("PASS: ");
  Serial.println(epass);
 
 
  WiFi.begin(esid.c_str(), epass.c_str());
  if (testWifi())
  {
    Serial.println("Succesfully Connected!!!");
    return;
  }
  else
  {
    Serial.println("Turning the HotSpot On");
    launchWeb();
    setupAP();// Setup HotSpot
  }
 
  Serial.println();
  Serial.println("Waiting.");
  
  while ((WiFi.status() != WL_CONNECTED))
  {
    Serial.print(".");
    delay(100);
    server.handleClient();
  }

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Initially, ESP8266 is set up in station mode and tries to connect to previously saved access points from EEPROM memory. If a correct access point network is found, it will be connected to it.

If this process fails, it sets ESP8266 to access point mode and creates a hotspot network.

void loop() {
  if ((WiFi.status() == WL_CONNECTED))
  {
 
    for (int i = 0; i < 10; i++)
    {
      digitalWrite(LED_BUILTIN, HIGH);
      delay(1000);
      digitalWrite(LED_BUILTIN, LOW);
      delay(1000);
    }
 
  }
  else
  {
  }

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In this section, you can enter your code as you wish. For now, I just blink the LED.

void createWebServer()
{
 {
    server.on("/", []() {
 
      IPAddress ip = WiFi.softAPIP();
      String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);
      content = "<!DOCTYPE HTML>\r\n<html>Hello from ESP8266 at ";
      content += "<form action=\"/scan\" method=\"POST\"><input type=\"submit\" value=\"scan\"></form>";
      content += ipStr;
      content += "<p>";
      content += st;
      content += "</p><form method='get' action='setting'><label>SSID: </label><input name='ssid' length=32><input name='pass' length=64><input type='submit'></form>";
      content += "</html>";
      server.send(200, "text/html", content);
    });
    server.on("/scan", []() {
      //setupAP();
      IPAddress ip = WiFi.softAPIP();
      String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);
 
      content = "<!DOCTYPE HTML>\r\n<html>go back";
      server.send(200, "text/html", content);
    });

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Project Demonstration

Using any WiFi-enabled device with any browser, connect to the newly created AP. After establishing a connection with the newly created access point, you can go to the default IP address 192.168.4.1 to open a web page that allows you to configure your SSID and password.

Once the new SSID and password are set, ESP reboots and tries to connect. If it establishes a connection, the process ends successfully. Otherwise, it will again be established as an access point.

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Source Code/Program

This is a complete source code for ESP8266 Manual Wifi Configuration with EEPROM without Hard-Code projects. Copy the below code in Arduino IDE and upload it to your ESP board by selecting the correct port.

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <ESP8266WebServer.h>
#include <EEPROM.h>
 
//Variables
int i = 0;
int statusCode;
const char* ssid = "text";
const char* passphrase = "text";
String st;
String content;
 
 
//Function Decalration
bool testWifi(void);
void launchWeb(void);
void setupAP(void);
 
//Establishing Local server at port 80 whenever required
ESP8266WebServer server(80);
 
void setup()
{
 
  Serial.begin(115200); //Initialising if(DEBUG)Serial Monitor
  Serial.println();
  Serial.println("Disconnecting previously connected WiFi");
  WiFi.disconnect();
  EEPROM.begin(512); //Initialasing EEPROM
  delay(10);
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.println();
  Serial.println();
  Serial.println("Startup");
 
  //---------------------------------------- Read EEPROM for SSID and pass
  Serial.println("Reading EEPROM ssid");
 
  String esid;
  for (int i = 0; i < 32; ++i)
  {
    esid += char(EEPROM.read(i));
  }
  Serial.println();
  Serial.print("SSID: ");
  Serial.println(esid);
  Serial.println("Reading EEPROM pass");
 
  String epass = "";
  for (int i = 32; i < 96; ++i)
  {
    epass += char(EEPROM.read(i));
  }
  Serial.print("PASS: ");
  Serial.println(epass);
 
 
  WiFi.begin(esid.c_str(), epass.c_str());
  if (testWifi())
  {
    Serial.println("Succesfully Connected!!!");
    return;
  }
  else
  {
    Serial.println("Turning the HotSpot On");
    launchWeb();
    setupAP();// Setup HotSpot
  }
 
  Serial.println();
  Serial.println("Waiting.");
  
  while ((WiFi.status() != WL_CONNECTED))
  {
    Serial.print(".");
    delay(100);
    server.handleClient();
  }
 
}
void loop() {
  if ((WiFi.status() == WL_CONNECTED))
  {
 
    for (int i = 0; i < 10; i++)
    {
      digitalWrite(LED_BUILTIN, HIGH);
      delay(1000);
      digitalWrite(LED_BUILTIN, LOW);
      delay(1000);
    }
 
  }
  else
  {
  }
 
}
 
 
//-------- Fuctions used for WiFi credentials saving and connecting to it which you do not need to change 
bool testWifi(void)
{
  int c = 0;
  Serial.println("Waiting for Wifi to connect");
  while ( c < 20 ) {
    if (WiFi.status() == WL_CONNECTED)
    {
      return true;
    }
    delay(500);
    Serial.print("*");
    c++;
  }
  Serial.println("");
  Serial.println("Connect timed out, opening AP");
  return false;
}
 
void launchWeb()
{
  Serial.println("");
  if (WiFi.status() == WL_CONNECTED)
    Serial.println("WiFi connected");
  Serial.print("Local IP: ");
  Serial.println(WiFi.localIP());
  Serial.print("SoftAP IP: ");
  Serial.println(WiFi.softAPIP());
  createWebServer();
  // Start the server
  server.begin();
  Serial.println("Server started");
}
 
void setupAP(void)
{
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(100);
  int n = WiFi.scanNetworks();
  Serial.println("scan done");
  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));
      Serial.print(" (");
      Serial.print(WiFi.RSSI(i));
      Serial.print(")");
      Serial.println((WiFi.encryptionType(i) == ENC_TYPE_NONE) ? " " : "*");
      delay(10);
    }
  }
  Serial.println("");
  st = "<ol>";
  for (int i = 0; i < n; ++i)
  {
    // Print SSID and RSSI for each network found
    st += "<li>";
    st += WiFi.SSID(i);
    st += " (";
    st += WiFi.RSSI(i);
 
    st += ")";
    st += (WiFi.encryptionType(i) == ENC_TYPE_NONE) ? " " : "*";
    st += "</li>";
  }
  st += "</ol>";
  delay(100);
  WiFi.softAP("The_IoT_Projects", "123456789");
  Serial.println("softap");
  launchWeb();
  Serial.println("over");
}
 
void createWebServer()
{
 {
    server.on("/", []() {
 
      IPAddress ip = WiFi.softAPIP();
      String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);
      content = "<!DOCTYPE HTML>\r\n<html>Hello from ESP8266 at ";
      content += "<form action=\"/scan\" method=\"POST\"><input type=\"submit\" value=\"scan\"></form>";
      content += ipStr;
      content += "<p>";
      content += st;
      content += "</p><form method='get' action='setting'><label>SSID: </label><input name='ssid' length=32><input name='pass' length=64><input type='submit'></form>";
      content += "</html>";
      server.send(200, "text/html", content);
    });
    server.on("/scan", []() {
      //setupAP();
      IPAddress ip = WiFi.softAPIP();
      String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);
 
      content = "<!DOCTYPE HTML>\r\n<html>go back";
      server.send(200, "text/html", content);
    });
 
    server.on("/setting", []() {
      String qsid = server.arg("ssid");
      String qpass = server.arg("pass");
      if (qsid.length() > 0 && qpass.length() > 0) {
        Serial.println("clearing eeprom");
        for (int i = 0; i < 96; ++i) {
          EEPROM.write(i, 0);
        }
        Serial.println(qsid);
        Serial.println("");
        Serial.println(qpass);
        Serial.println("");
 
        Serial.println("writing eeprom ssid:");
        for (int i = 0; i < qsid.length(); ++i)
        {
          EEPROM.write(i, qsid[i]);
          Serial.print("Wrote: ");
          Serial.println(qsid[i]);
        }
        Serial.println("writing eeprom pass:");
        for (int i = 0; i < qpass.length(); ++i)
        {
          EEPROM.write(32 + i, qpass[i]);
          Serial.print("Wrote: ");
          Serial.println(qpass[i]);
        }
        EEPROM.commit();
 
        content = "{\"Success\":\"saved to eeprom... reset to boot into new wifi\"}";
        statusCode = 200;
        ESP.reset();
      } else {
        content = "{\"Error\":\"404 not found\"}";
        statusCode = 404;
        Serial.println("Sending 404");
      }
      server.sendHeader("Access-Control-Allow-Origin", "*");
      server.send(statusCode, "application/json", content);
 
    });
  } 
}

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Video Demonstration: ESP8266 Manual Wifi Configuration with EEPROM

This is a complete video demonstration on ESP8266 Manual Wifi Configuration with EEPROM without Hard coding it.

Conclusion

In this tutorial, I have shown you ESP8266 Manual Wifi Configuration with EEPROM without Hard-Code. This tutorial will be helpful to built ESP8266 based IoT device. I hope you enjoyed reading this article. If you have any questions, comments, or ideas? Let me know in the comment section below.

These are some ESP8266 based IoT Projects:

• Secure HTTPS Requests to URL Using NodeMCU ESP8266
• IoT Based Patient Health Monitoring System Using ESP8266/ESP32 Web Server
• BME280 Based Mini Weather Station using ESP8266/ESP32
• ESP8266 based IoT Health Care Panic Alarm for Elderly Folks
• Home Automation with ESP8266 Web Server & Relay Module Control Appliances from Local Network
• Home Automation with MIT App Inventor and ESP8266
• RFID Based Attendance System Using NodeMCU with PHP Web App
• ESP8266 RGB LED Controller Web Server
• Password Security Lock System Using Arduino & Keypad
• Temperature Controlled Home Automation using Arduino
• ESP8266 Plot Sensor readings to Webserver in Real-Time Chart

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