#include <LiquidCrystal_I2C.h>



// Pin Definitions

#define LOAD_RELAY_PIN 13

#define CHARGE_RELAY_PIN 12

#define VOLTAGE_SENSOR_PIN A0



// LCD Pin Configuration

LiquidCrystal_I2C lcd(0X27,20,4);



// Voltage Cutoff Levels

#define FULL_CUT_VOLTAGE 13.6 // Maximum voltage before charging stops

#define LOW_CUT_VOLTAGE 10.6 // Minimum voltage before load disconnects



// Variables

float batteryVoltage = 0;



void setup() {

lcd.begin(16, 2); // Initialize the LCD

lcd.print("12V AutoCut");
lcd.backlight();
delay(2000);



// Configure relay pins as output

pinMode(LOAD_RELAY_PIN, OUTPUT);

pinMode(CHARGE_RELAY_PIN, OUTPUT);



// Start with relays off

digitalWrite(LOAD_RELAY_PIN, LOW);

digitalWrite(CHARGE_RELAY_PIN, LOW);

}



void loop() {

// Read battery voltage

int sensorValue = analogRead(VOLTAGE_SENSOR_PIN);

batteryVoltage = (sensorValue / 1023.0) * 5.0 * ((10.0 + 5.6) / 5.6); // Adjust for voltage divider



// Update LCD Display

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Battery: ");

lcd.print(batteryVoltage);

lcd.print("V");



// Check voltage levels and control relays

if (batteryVoltage > FULL_CUT_VOLTAGE) {

digitalWrite(CHARGE_RELAY_PIN, LOW); // Stop charging

lcd.setCursor(0, 1);

lcd.print("Charging: OFF");

} else {

digitalWrite(CHARGE_RELAY_PIN, HIGH); // Start charging

lcd.setCursor(0, 1);

lcd.print("Charging: ON ");

}



if (batteryVoltage < LOW_CUT_VOLTAGE) {

digitalWrite(LOAD_RELAY_PIN, LOW); // Disconnect load

lcd.setCursor(0, 1);

lcd.print("Load: OFF ");

} else {

digitalWrite(LOAD_RELAY_PIN, HIGH); // Connect load

lcd.setCursor(0, 1);

lcd.print("Load: ON ");

}



delay(1000); // Update every second

}