// Give me arduino nano code 


// inputVoltageSensorPotPin  = A1
// outputVoltageSensorPotPin = A0

// Connected 16x2 I2C lcd 

// ServoMotorPin = D3 

// int setVoltage = 230 // V AC
// int servoSteps = 1 // degree steps

// ready the inputPot : range from 0 to 270V AC 
// ready the outputPot : range from 0 to 270V AC 
// Display it on the LCD 

// condition if the inputPotValue is < setVoltage rotate the servo motor by steps = servoSteps increment
// condition if the inputPotValue is > setVoltage rotate the servo motor by steps = servoSteps decrement





// No 
// the output voltage should be in range + and - : setVoltage
// and if the output voltage is less then rotate the servo clockvise to increase voltage else rotate anit clockvise to decre the volatge




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

// ------------------ Pin Definitions ------------------
const int inputVoltageSensorPotPin  = A1;
const int outputVoltageSensorPotPin = A0;
const int servoMotorPin = 3;  // D3

// ------------------ LCD Setup ------------------
LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16x2 LCD

// ------------------ Servo Setup ------------------
Servo servoMotor;
int servoPosition = 90;  // initial servo position (middle)

// ------------------ Voltage & Servo Settings ------------------
const int setVoltage = 230;     // target voltage in VAC
const int servoSteps = 1;       // steps to rotate servo per loop

// ------------------ Function to map analog to voltage ------------------
float readVoltage(int analogPin) {
  int analogValue = analogRead(analogPin); // 0-1023
  float voltage = map(analogValue, 0, 1023, 0, 270); // map to 0-270V AC
  return voltage;
}

void setup() {
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();

  // Initialize Servo
  servoMotor.attach(servoMotorPin);
  servoMotor.write(servoPosition);

  // Initial display
  lcd.setCursor(0, 0);
  lcd.print("InputV: ");
  lcd.setCursor(0, 1);
  lcd.print("OutputV: ");
}

void loop() {
  // Read voltages
  float inputVoltage  = readVoltage(inputVoltageSensorPotPin);
  float outputVoltage = readVoltage(outputVoltageSensorPotPin);

  // Display on LCD
  lcd.setCursor(8, 0);
  lcd.print(inputVoltage, 1);
  lcd.print("V   ");

  lcd.setCursor(8, 1);
  lcd.print(outputVoltage, 1);
  lcd.print("V   ");

  // Control Servo based on output voltage relative to set voltage
  if (outputVoltage < setVoltage && servoPosition < 180) {
    // Rotate clockwise to increase output voltage
    servoPosition += servoSteps;
    if (servoPosition > 180) servoPosition = 180;
    servoMotor.write(servoPosition);
  } 
  else if (outputVoltage > setVoltage && servoPosition > 0) {
    // Rotate counter-clockwise to decrease output voltage
    servoPosition -= servoSteps;
    if (servoPosition < 0) servoPosition = 0;
    servoMotor.write(servoPosition);
  }

  delay(100); // small delay for stability
}