#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

// Define pin numbers for voltage sensors and relays
const int voltageSensor1Pin = A0; // Voltage sensor for Battery 1
const int voltageSensor2Pin = A1; // Voltage sensor for Battery 2
const int relaySignalPin1 = 2; // Pin connected to the relay signal input for Battery 1
const int relaySignalPin2 = 3; // Pin connected to the relay signal input for Battery 2

// Define voltage threshold for low battery (24V specification)
const float lowVoltageThreshold = 20.0; // 20.0V

// Initialize the LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Initialize relay signal pins as output
  pinMode(relaySignalPin1, OUTPUT);
  pinMode(relaySignalPin2, OUTPUT);
  
  // Initialize LCD
  lcd.init(); // Initialize the LCD 
  lcd.backlight(); // Turn on backlight
  lcd.setCursor(0,0);
  lcd.print("Battery 1: ");
  lcd.setCursor(0,1);
  lcd.print("Battery 2: ");
}

void loop() {
  // Read voltage levels of both batteries
  float voltage1 = analogRead(voltageSensor1Pin) * (5.0 / 1023.0) * 10; // Convert analog value to voltage (assuming reference voltage of 5V) and scale for 24V battery
  float voltage2 = analogRead(voltageSensor2Pin) * (5.0 / 1023.0) * 10;

  // Display voltage and state for Battery 1
  lcd.setCursor(10,0);
  lcd.print(voltage1, 1);
  lcd.print("V ");
  if (voltage1 < lowVoltageThreshold) {
    lcd.print("(Discharging)");
  } else {
    lcd.print("(Charging)");
  }

  // Display voltage and state for Battery 2
  lcd.setCursor(10,1);
  lcd.print(voltage2, 1);
  lcd.print("V ");
  if (voltage2 < lowVoltageThreshold) {
    lcd.print("(Discharging)");
  } else {
    lcd.print("(Charging)");
  }

  // Check voltage levels and set relay signal accordingly for Battery 1
  if (voltage1 < lowVoltageThreshold) {
    // Battery 1 is low, set relay signal high to connect to load
    digitalWrite(relaySignalPin1, HIGH);
  } else {
    // Battery 1 is not low, set relay signal low to connect to charging
    digitalWrite(relaySignalPin1, LOW);
  }

  // Check voltage levels and set relay signal accordingly for Battery 2
  if (voltage2 < lowVoltageThreshold) {
    // Battery 2 is low, set relay signal high to connect to load
    digitalWrite(relaySignalPin2, HIGH);
  } else {
    // Battery 2 is not low, set relay signal low to connect to charging
    digitalWrite(relaySignalPin2, LOW);
  }

  // Add a delay to prevent continuous looping too quickly
  delay(1000); // Adjust delay time as needed
}