Code for interfacing DS3231 RTC Module in ESP8266 WiFi Module/NodeMCU

Learn_interfacing_DS3231_RTC_Module_in_ESP8266_WiFi_Module_NodeMCU.ino

#include <Wire.h>
#include <RtcDS3231.h>
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>

RtcDS3231<TwoWire> Rtc(Wire);
ESP8266WebServer server(80);

const char* ssid = "ESPWiFi";
const char* password =  "Password";

int hh=0,mm=0;

void setup () 
{
    Serial.begin(115200);
    Rtc.Begin();

    RtcDateTime compiled = RtcDateTime(__DATE__, __TIME__);
    if (!Rtc.IsDateTimeValid()) 
    {
        Serial.println("RTC lost confidence in the DateTime!");
        Rtc.SetDateTime(compiled);
    }

    RtcDateTime now = Rtc.GetDateTime();
    
    Rtc.Enable32kHzPin(false);
    Rtc.SetSquareWavePin(DS3231SquareWavePin_ModeNone);
    
    WiFi.begin(ssid, password);  //Connect to the WiFi network
 
    while (WiFi.status() != WL_CONNECTED) {  //Wait for connection
      delay(500);
      Serial.println("Waiting to connect...");
    }
    
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP());  //Print the local IP
  
    server.on("/", handle_index);
    
    server.begin(); //Start the server
}

void loop () 
{
    server.handleClient(); //Handling of incoming requests
    RtcDateTime now = Rtc.GetDateTime();
    //Print RTC time to Serial Monitor
    Serial.print("Date:");
    Serial.println(now.Year(), DEC);
    Serial.print('/');
    Serial.print(now.Month(), DEC);
    Serial.print('/');
    Serial.print(now.Day(), DEC);
    Serial.print(" Time:");
    Serial.print(now.Hour(), DEC);
    Serial.print(':');
    Serial.print(now.Minute(), DEC);
    Serial.print(':');
    Serial.print(now.Second(), DEC);
    
    delay(1000); // one second
}

void handle_index() {
  server.send(200, "text/plain", "This is an index page.");
}