Energy Consumption Monitoring System

#include <Wire.h>
#include <RTClib.h>

RTC_DS3231 rtc;

const int relayPin1 = 2;
const int relayPin2 = 3;

const float powerDevice1 = 60.0; // in watts
const float powerDevice2 = 75.0; // in watts

DateTime startTime1, startTime2;
DateTime endTime1, endTime2;

float energyConsumed1 = 0.0;
float energyConsumed2 = 0.0;

void setup() {
  Serial.begin(9600);
  pinMode(relayPin1, INPUT);
  pinMode(relayPin2, INPUT);
  
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
}

void loop() {
  if (digitalRead(relayPin1) == HIGH) {
    startTime1 = rtc.now();
    while (digitalRead(relayPin1) == HIGH) {
      // Device is ON
    }
    endTime1 = rtc.now();
    float duration1 = (endTime1.unixtime() - startTime1.unixtime()) / 3600.0; // in hours
    energyConsumed1 += (powerDevice1 / 1000.0) * duration1; // in kWh
    Serial.print("Energy consumed by Device 1: ");
    Serial.print(energyConsumed1);
    Serial.println(" kWh");
  }

  if (digitalRead(relayPin2) == HIGH) {
    startTime2 = rtc.now();
    while (digitalRead(relayPin2) == HIGH) {
      // Device is ON
    }
    endTime2 = rtc.now();
    float duration2 = (endTime2.unixtime() - startTime2.unixtime()) / 3600.0; // in hours
    energyConsumed2 += (powerDevice2 / 1000.0) * duration2; // in kWh
    Serial.print("Energy consumed by Device 2: ");
    Serial.print(energyConsumed2);
    Serial.println(" kWh");
  }
}