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

const int POT_PIN = A0; // Pin A0 for potentiometer
const float REFERENCE_VOLTAGE = 5.0; // ADC reference voltage
// Initialize the I2C LCD interface (address 0x27, 16 columns, 2 rows)
LiquidCrystal_I2C lcd(0x27, 16, 2); 

void setup() {
  // Initialize serial communication at 9600 baud
  Serial.begin(9600);
  // Initialize LED pins
  pinMode(3, OUTPUT); //Green LED
  pinMode(4, OUTPUT); //Yellow LED
  pinMode(5, OUTPUT); //GRed LED
  // Initialize the LCD display
  lcd.init();
  lcd.backlight();
  //Set all LED's low
  digitalWrite(3,LOW); //Green LED
  digitalWrite(4,LOW); //Yellow LED
  digitalWrite(5,LOW); //Red LED
}

void loop() {
  // Read the analog voltage from the potentiometer
  int analog_value = analogRead(POT_PIN);
  // Convert the analog value to a voltage in volts
  float voltage = analog_value * (REFERENCE_VOLTAGE / 1023.0);
  // Convert the analog value to a string for printing to the LCD display
  char analog_string[7];
  dtostrf(voltage, 5, 2, analog_string);

  // Print the voltage in volts and the digital value in decimal format
  // to the LCD display and the serial monitor
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Voltage: ");
  lcd.print(analog_string);
  lcd.print(" V");
  lcd.setCursor(0, 1);
  lcd.print("Level: ");

  if(voltage >= (0.0) && voltage <= (2.0)){
    digitalWrite(3,HIGH); //Green LED
    digitalWrite(4,LOW); //Yellow LED
    digitalWrite(5,LOW); //Red LED
    lcd.print("LOW     ");
  }
  else if(voltage >= (2.01) && voltage <= (3.5)){
    digitalWrite(3,LOW); //Green LED
    digitalWrite(4,HIGH); //Yellow LED
    digitalWrite(5,LOW); //Red LED
    lcd.print("MEDIUM      ");
  }
  else {
    digitalWrite(3,LOW); //Green LED
    digitalWrite(4,LOW); //Yellow LED
    digitalWrite(5,HIGH); //Red LED
    lcd.print("HIGH      ");
  }

  Serial.print("Voltage: ");
  Serial.print(analog_string);
  Serial.print(" V, Digital: ");
  Serial.print(analog_value);
  Serial.print(", Level: ");
    if(voltage >= (0.0) && voltage <= (2.0))
    Serial.println("LOW");
    else if(voltage >= (2.01) && voltage <= (3.5))
    Serial.println("MEDIUM");
    else 
    Serial.println("HIGH");
  delay(100); // Delay for 100 ms before taking the next reading
}