const float Vmax = 3.3; // ADC maximum inout voltage
const int ADCmax = 4095; // 12 BIT ADC 10'12

// ESP32 pin reference
const int LED = 2; //GPIO2 onboard LED, connecting an externa LED too
const int POT_ADC = 4;  // GPIO4 - ADC0
const int PButton = 5;
boolean sw_state;

void setup() {
  Serial.begin(115200);
  pinMode(LED,OUTPUT);
  pinMode(PButton, INPUT);
  digitalWrite(LED,LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  int PotADCin = analogRead(POT_ADC);
  float PotV = Vmax * PotADCin / ADCmax;
  boolean sw_s = digitalRead(PButton);
  if (sw_s == true){
    sw_state = !sw_state;
    delay(200);
  }
  Serial.print("123456789");
  Serial.print("\t");
  Serial.print("LED:");
  if (sw_state == true){
    Serial.print("ON ");
    digitalWrite(LED,HIGH);
  }else{
    Serial.print("OFF");
    digitalWrite(LED,LOW);
  }
  Serial.print("\t\t");
  Serial.print(PotADCin);
  Serial.print("\t");
  Serial.print(PotV);
  Serial.println(" v");
  delay(500);
}