#include <Wire.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x3f, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);

float R1 = 30000;

float R2 = 7500;

float  offset = 0;

void setup()

 {

  Serial.begin(9600);

  lcd.begin(16, 2);

  lcd.setCursor(0, 0);

  lcd.print("Voltage :");

}

void loop() {

  int sensorValue = analogRead(A0) + offset;

  float voltage = (5 * sensorValue * (R1 + R2)) / (1024 * R2);

  Serial.println(voltage);

  lcd.setCursor(9, 0);

  lcd.print (voltage);

  lcd.setCursor(0, 1);

  if (voltage > 1.28)

  {

    lcd.print("Good      ");

  }

 else if (voltage < 1.27 && voltage  > 1.15){

lcd.print("Low Power");

  }

  else if (voltage==0){

lcd.print("No Battery ");

  }

  else{

lcd.print("Replace   ");

}

  delay(1000);

}