// Potentiometer is connected to GPIO 34 (Analog ADC1_CH6) 
const int potPin = 15;

// variable for storing the potentiometer value
int ADC = 0;
float volt = 0.0;

void setup() {
  Serial.begin(115200);
  pinMode(4, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(13, OUTPUT);
  delay(1000);
}

void loop() {
  // Reading potentiometer value
  ADC = analogRead(potPin);
  volt = 3.3*ADC/4095;
  Serial.print("Analog value: ");
  Serial.print(ADC);
  Serial.print(" volt: ");
  Serial.println(volt);
  delay(100);
  
  if (volt >= 0.4 && volt < 0.8) {
    digitalWrite(4, HIGH);
    delay(200);
  }
  if (volt >= 0.8 && volt < 1.65 ) {
      digitalWrite(2, HIGH);
      delay(200);
    }

  if (volt >= 1.65 && volt <= volt) {
    digitalWrite(13, HIGH);
    delay(200);
  }
  else{
    digitalWrite(4, LOW);
    digitalWrite(2, LOW);
    digitalWrite(13, LOW);
  }
}