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

// Define pins
#define BATTERY_PIN A0       // Analog pin for battery voltage monitoring
#define RELAY1_PIN 7         // Digital pin to control relay 1
#define RELAY2_PIN 4         // Digital pin to control relay 2

// Define voltage thresholds for each relay (adjust these according to your setup)
#define RELAY1_MAX_VOLTAGE 20.8  // Relay 1: Maximum battery voltage before diverting (28.8V)
#define RELAY1_MIN_VOLTAGE 20.0  // Relay 1: Minimum battery voltage to stop diverting

#define RELAY2_MAX_VOLTAGE 29.5  // Relay 2: Maximum battery voltage before diverting (29.5V)
#define RELAY2_MIN_VOLTAGE 25.0  // Relay 2: Minimum battery voltage to stop diverting

// Voltage divider resistors values (in ohms)
#define R1 10000.0           // 10kΩ resistor
#define R2 2000.0            // 2kΩ resistor

// Initialize the LCD with I2C address 0x27 and size 16x2
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Function to read the battery voltage
float readBatteryVoltage() {
    int sensorValue = analogRead(BATTERY_PIN);  // Read the analog pin value (0-1023)
    float voltage = sensorValue * (5.0 / 1023.0);  // Convert to voltage (0-5V)
    voltage = voltage * ((R1 + R2) / R2);  // Convert to the actual battery voltage
    return voltage;
}

void setup() {
    // Initialize serial communication for debugging
    Serial.begin(9600);

    // Initialize the relay pins as output
    pinMode(RELAY1_PIN, OUTPUT); 
    pinMode(RELAY2_PIN, OUTPUT);
    digitalWrite(RELAY1_PIN, LOW);  // Ensure relay 1 is off initially
    digitalWrite(RELAY2_PIN, LOW);  // Ensure relay 2 is off initially

    // Initialize the LCD
    lcd.begin(16, 2);  // Specify the number of columns and rows
    lcd.backlight();  // Turn on the LCD backlight
}

void loop() {
    float batteryVoltage = readBatteryVoltage();  // Read the current battery voltage
    Serial.print("Battery Voltage: ");
    Serial.println(batteryVoltage);  // Print the battery voltage to the serial monitor

    // Display battery voltage on the LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Batt Voltage:");
    lcd.setCursor(0, 1);
    lcd.print(batteryVoltage);
    lcd.print(" V");

    // Control Relay 1
    if (batteryVoltage >= RELAY1_MAX_VOLTAGE) {
        Serial.println("Relay 1: Over-voltage detected! Diverting load to heating element.");
        digitalWrite(RELAY1_PIN, HIGH);  // Activate relay 1 to divert the load
    } else if (batteryVoltage <= RELAY1_MIN_VOLTAGE) {
        Serial.println("Relay 1: Battery voltage normal. Stopping load diversion.");
        digitalWrite(RELAY1_PIN, LOW);  // Deactivate relay 1 to stop diverting the load
    }

    // Control Relay 2
    if (batteryVoltage >= RELAY2_MAX_VOLTAGE) {
        Serial.println("Relay 2: Over-voltage detected! Diverting load to heating element.");
        digitalWrite(RELAY2_PIN, HIGH);  // Activate relay 2 to divert the load
    } else if (batteryVoltage <= RELAY2_MIN_VOLTAGE) {
        Serial.println("Relay 2: Battery voltage normal. Stopping load diversion.");
        digitalWrite(RELAY2_PIN, LOW);  // Deactivate relay 2 to stop diverting the load
    }

    delay(1000);  // Wait for 1 second before the next loop
}