Published October 22, 2023 © LGPL

ESP32 WiFi sketch for "Access Point" or "Station Mode"

This "setup" sketch allows quickly change to "Access Point" or "Station Mode" with fixed IP or DHCP by only modifying a configuration file.

IntermediateProtip1 hour365

ESP32 WiFi sketch for "Access Point" or "Station Mode"

Things used in this project

Hardware components

Espressif ESP32 Development Board - Developer Edition

Software apps and online services

Arduino IDE

Story

I use ESP32s while traveling or at home. Different approaches to connecting the ESP32's WiFi are possible. At home I have a router that I can connect to. But this is not the case in nomadic use. I use then the possibility of configuring the ESP32 in "Access Point" mode.

Every sketch I write, I have to reconfigure the section concerning the WiFi connection. This is not practical and is prone to errors. This little module uses conditional compilation in the Arduino IDE. It allows you to configure all the parameters in a small “wifi_cfg.h” file which can be pre-filled. All you have to do is modify the operating mode and possibly an IP address to have a functional WiFi connection.

The configuration file "wifi_cfg.h"

Only this file need to be edited for changing anything in your WiFi configuration. This file can contain pre-filled, the settings for your WiFi configuration. The hostname can also be set, but I did not notice any changes...

Note that there are also the credentials to connect to your WiFi network in "station mode" and the credentials (ssid and password) of the access point that you can create. So be carefull with this file if you pass the files to somebody.

Selection of Station mode is done by Commenting Out "#define AP".If "#define AP" is not Commented Out the ESP32 will work as Access Point. The IP parameters defined in section "// IP parameters for Access Point" are used.
If "#define STATIC_IP" is Commented Out dhcp is used.If "#define STATIC_IP" is not Commented Out, static IP with the parameters defined in section "// IP parameters for Station mode with fixed IP" are used.

The procedure “ESP32_WiFi.h”

This procedure uses conditional compilation so that the generated code agrees with the parameters you defined in the "wifi_cfg.h" file.

There is no need to modify this file unless you want to remove the "Serial.print()" feature.

You no longer have to rack your brains, search for the parameters of your WiFi network, or do research when you want to switch from dhcp to fixed IP, or even use the ESP32 as an "Access Point".

How to use it

Place the files "wifi_cfg.h" and "ESP32_WiFi.h" in the the same directory as your sketch.
Edit "wifi_cfg.h" for your settings.
In your sketch ad a line: #include "ESP32_WiFi.h"
and in the setup, call the procedure: WiFi_setup();

See the "Example_WiFi.ino".

There may be other ways to do this, but I don't have enough programming knowledge to go further.

// **********************************************************************************
// *  ESP32 WiFi sketch for "Access Point" or "Station Mode" with fixed IP or DHCP  *
// *                                                                                *
// *   This file must be used in conjunction with the "wifi.cfg" file containing    *
// *   your network settings and credentials.                                       *
// *                                                Daniel Engel    21/10/2023      *
// **********************************************************************************

#include <WiFi.h>
#include "wifi_cfg.h"  // this is the file where you wrote the WiFi credentials

void WiFi_setup() {
  String ssid, password;

#if defined(AP)  // ESP32 will work as an access point
  ssid = SSID_AP;
  password = PWD_AP;
  WiFi.mode(WIFI_AP);
  WiFi.softAP(ssid, password);
  WiFi.softAPConfig(AP_IP, AP_GW, AP_SUB, AP_DHCP);
  Serial.print("[+] AP Created with SSID: ");
  Serial.print(ssid);
  Serial.print("   IP: ");
  Serial.println(WiFi.softAPIP());

#elif defined(STATIC_IP)  // ESP32 will work as an access point
  ssid = SSID_STA;
  password = PWD_STA;
  WiFi.mode(WIFI_STA);
  WiFi.setHostname(hostname.c_str());  //define hostname
  IPAddress staticIP(STA_IP);
  IPAddress gateway(STA_GW);
  IPAddress subnet(STA_SUB);
  IPAddress primaryDNS(STA_DNS1);
  IPAddress secondaryDNS(STA_DNS2);
  if (WiFi.config(staticIP, gateway, subnet, primaryDNS, secondaryDNS) == false) {
    Serial.println("Configuration failed.");
  }
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.print("Static IP mode --- ");
  Serial.print("Connected to network with IP address: ");
  Serial.println(WiFi.localIP());

#else  // ESP32 will connect to your router in Station mode using DHCP
  ssid = SSID_STA;
  password = PWD_STA;
  WiFi.mode(WIFI_STA);
  WiFi.setHostname(hostname.c_str());  //define hostname
  WiFi.begin(ssid, password);
  Serial.println("Establishing connection to WiFi with SSID: " + String(ssid));
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.print("DHCP mode --- ");
  Serial.print("Connected to network with IP address: ");
  Serial.println(WiFi.localIP());
#endif
}

/* ******************************************************************************** 
   *  Complete this file with the settings you want and your network credentials  *
   *                                                                              *
   *  Comment/uncomment "#define AP" and "#define STATIC_IP" to match your usage  *
   ******************************************************************************** */

/* Choice your hostname */
String hostname = "ESP32_WiFi_CFG";

/*___________________________________________________________*/
/*  Comment/uncomment to choice WiFi mode and IP parameters  */
/**/
#define AP         // Comment for Station mode, Uncomment: Access Point mode
#define STATIC_IP  // Comment for using DHCP in Station mode

//    ssid and password for the Access Point
// -> DO NOT use the SSID/Password of your router !!!
#define SSID_AP "My_ESP32"
#define PWD_AP "12345678"  //  empty string for open or at least 8 characters
// if there are not enough characters it doesn't work but no compiler warning !!!

// IP parameters for Access Point  (modify to meet your needs)
IPAddress AP_IP = IPAddress(192, 168, 22, 22);
IPAddress AP_GW = IPAddress(192, 168, 22, 22);
IPAddress AP_SUB = IPAddress(255, 255, 255, 0);
IPAddress AP_DHCP = IPAddress(192, 168, 22, 30);

// SSID and password of your router for "Station mode" (used for dhcp and fixed IP)
#define SSID_STA "MY_SSID"
#define PWD_STA "MY_PASSWORD"

// IP parameters in case of "Station mode with fixed IP"
IPAddress STA_IP(192, 168, 0, 121);
IPAddress STA_GW(192, 168, 0, 1);
IPAddress STA_SUB(255, 255, 255, 0);
IPAddress STA_DNS1(192, 168, 0, 1);
IPAddress STA_DNS2(192, 168, 0, 1);

ESP32 WiFi sketch for "Access Point" or "Station Mode"

Things used in this project

Hardware components

Software apps and online services

Story

The configuration file "wifi_cfg.h"

The procedure “ESP32_WiFi.h”

How to use it

Code

ESP32_WiFi

wifi_cfg

Example_WiFi

Example_WiFi.zip

Credits

daniel23

Comments

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ESP32 WiFi sketch for "Access Point" or "Station Mode"

ESP32 WiFi sketch for "Access Point" or "Station Mode"

Things used in this project

Hardware components

Software apps and online services

Story

The configuration file "wifi_cfg.h"

The procedure “ESP32_WiFi.h”

How to use it

Code

ESP32_WiFi

wifi_cfg

Example_WiFi

Example_WiFi.zip

Credits

daniel23

Comments

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