Connecting an ESP8266 to WiFi without hardcoding the credentials

Question

I've recently achieved connecting my board, an ESP8266 to my local WiFi, but I've had to hardcode the credentials to the code, just like in 99% of the tutorials online. My code looks somewhat like this:

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266HTTPClient.h>

#define USE_SERIAL Serial

ESP8266WiFiMulti WiFiMulti;

void setup() {

    USE_SERIAL.begin(115200);

    WiFi.mode(WIFI_STA);
    WiFiMulti.addAP("SSID", "Password");

}

void loop() {
    // Some more code
}

The thing is, I would like to know if there is some way to parametrize the credentials so I don't have to recompile and upload the code to the board everytime my WiFi password changes.

One of my ideas was to connect all the boards to a local router without actual connection to the internet and have a server in that same LAN manage the sensitive information, not the boards. That would allow me to manage credentials properly. Does this even make sense?

Answer 1

The common way to do this is to put the ESP8266 into AP (Access Point) mode and then serve a web page with the configuration interface.

To make it even easier, you can create a captive portal so that the user doesn't need to open a specific IP address in their browser. The captive portal will cause the configuration page to be loaded no matter what address they open.

A popular Arduino library that makes this all very easy is WiFiManager:

https://github.com/tzapu/WiFiManager