//Mux control pins
const int s0 = 2;
const int s1 = 4;
const int s2 = 5;
const int s3 = 18;

//Mux in "SIG" pin
const int SIG_pin = 19;
byte controlPin[] = { s0, s1, s2, s3 };

byte readMux(byte channel) {
  // Loop a través de los 4 selectores
  for (byte b = 0; b < 4; b++, channel >>= 1)   {
    digitalWrite(controlPin[b], channel & 1);
  }
  // Leo y devuelvo el valor
  return digitalRead(SIG_pin);
}

void setup(){
  pinMode(s0, OUTPUT); 
  pinMode(s1, OUTPUT); 
  pinMode(s2, OUTPUT); 
  pinMode(s3, OUTPUT); 
  pinMode(SIG_pin, INPUT_PULLUP); 

  digitalWrite(s0, LOW);
  digitalWrite(s1, LOW);
  digitalWrite(s2, LOW);
  digitalWrite(s3, LOW);

  Serial.begin(9600);
}


void loop(){
  byte tmp = 0;

  //Loop through and read all 16 values
  //Reports back Value at channel 6 is: 346
  for(int i = 0; i < 16; i ++){
    tmp = readMux(i);
    if (tmp == 0) {
        Serial.printf("Canal %2d: %x\n", i, tmp);
    }
    delay(100);
   }
}