const float ADC_VREF_V = 5.0; // ADC reference voltage in volts (5 V)
const int ADC_RESOLUTION = 4095; // ADC resolution (2^12 - 1)
const int analogPin = 2; // Pin for reading the analog input (e.g., potentiometer)
int previousValue = 0; // Variable to store the previous analog value
const byte pinRed = 18; // Pin connected to the red LED
const byte pinGreen = 19; // Pin connected to the green LED
const byte pinYellow = 5; // Pin connected to the green LED

void setup() {
  pinMode(pinRed, OUTPUT); // Set the red LED pin as an output
  pinMode(pinGreen, OUTPUT); // Set the green LED pin as an output
  pinMode(pinYellow, OUTPUT); // Set the green LED pin as an output
  digitalWrite(pinRed, LOW); // Initialize the red LED to be OFF
  digitalWrite(pinGreen, LOW); // Initialize the green LED to be OFF
  digitalWrite(pinYellow, LOW); // Initialize the green LED to be OFF
  Serial.begin(115200); // Start serial communication at 115200 baud rate
  delay(1000); // Wait for 1 second to allow system initialization
  pinMode(analogPin, INPUT); // Set the analog pin as an input
}

void loop() {
  int analogValue = analogRead(analogPin); // Read the analog value from the analog pin

  Serial.print("Analog Value: "); // Print the analog value on the serial monitor
  Serial.println(analogValue);

  float voltage = analogValue * (ADC_VREF_V / ADC_RESOLUTION); // Calculate the voltage (scale of 5V)
  Serial.print("Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");

  if (voltage >= 3.0) { 
    digitalWrite(pinRed, HIGH); 
    digitalWrite(pinGreen, LOW); 
    digitalWrite(pinYellow, LOW); 
  } else if (voltage < 3.0 and voltage >2) { 
    digitalWrite(pinRed, LOW);
    digitalWrite(pinYellow, LOW); 
    digitalWrite(pinGreen, HIGH); 
  }   else if (voltage < 2.0) { 
    digitalWrite(pinRed, LOW);
    digitalWrite(pinYellow, HIGH); 
    digitalWrite(pinGreen, LOW); 
  }

  if (analogValue != previousValue) { 
    previousValue = analogValue; 
  }

  delay(250); 
}