int s3=12;
int s2=11;
int s1=10;
int s0=9;
int e1=8;
int e2=7;
int e3=6;
int e4=5;
int e5=4;
int e6=3;

void setup() {
  for(int pin=3;pin<=8;pin++){
    pinMode(pin, OUTPUT);
    digitalWrite(pin, HIGH);
  }
    for(int pin=9;pin<=12;pin++){
    pinMode(pin, OUTPUT);
    digitalWrite(pin, LOW);
  }
}
void ch0(){
  digitalWrite(s0, LOW);
  digitalWrite(s1, LOW);
  digitalWrite(s2, LOW);
  digitalWrite(s3, LOW);
}
void ch1(){
  digitalWrite(s0, HIGH);
  digitalWrite(s1, LOW);
  digitalWrite(s2, LOW);
  digitalWrite(s3, LOW);
}
void ch2(){
  digitalWrite(s0, LOW);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, LOW);
  digitalWrite(s3, LOW);
}
void ch3(){
  digitalWrite(s0, HIGH);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, LOW);
  digitalWrite(s3, LOW);
}
void ch4(){
  digitalWrite(s0, LOW);
  digitalWrite(s1, LOW);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, LOW);
}
void ch5(){
  digitalWrite(s0, HIGH);
  digitalWrite(s1, LOW);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, LOW);
}
void ch6(){
  digitalWrite(s0, LOW);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, LOW);
}
void ch7(){
  digitalWrite(s0, HIGH);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, LOW);
}
void ch8(){

  digitalWrite(s0, LOW);
  digitalWrite(s1, LOW);
  digitalWrite(s2, LOW);
  digitalWrite(s3, HIGH);
}
void ch9(){

  digitalWrite(s0, HIGH);
  digitalWrite(s1, LOW);
  digitalWrite(s2, LOW);
  digitalWrite(s3, HIGH);
}
void ch10(){

  digitalWrite(s0, LOW);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, LOW);
  digitalWrite(s3, HIGH);
}
void ch11(){

  digitalWrite(s0, HIGH);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, LOW);
  digitalWrite(s3, HIGH);
}
void ch12(){

  digitalWrite(s0, LOW);
  digitalWrite(s1, LOW);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, HIGH);
}
void ch13(){

  digitalWrite(s0, HIGH);
  digitalWrite(s1, LOW);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, HIGH);
}
void ch14(){

  digitalWrite(s0, LOW);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, HIGH);
}
void ch15(){

  digitalWrite(s0, HIGH);
  digitalWrite(s1, HIGH);
  digitalWrite(s2, HIGH);
  digitalWrite(s3, HIGH);
}

void multiplexer(int module,int time_delay){
  if(module==1){
    digitalWrite(e1,LOW);
    digitalWrite(e2,HIGH);
    digitalWrite(e3,HIGH);
    digitalWrite(e4,HIGH);
    digitalWrite(e5,HIGH);
    digitalWrite(e6,HIGH);
  }else if(module==2){
    digitalWrite(e1,HIGH);
    digitalWrite(e2,LOW);
    digitalWrite(e3,HIGH);
    digitalWrite(e4,HIGH);
    digitalWrite(e5,HIGH);
    digitalWrite(e6,HIGH);
  }else if(module==3){
    digitalWrite(e1,HIGH);
    digitalWrite(e2,HIGH);
    digitalWrite(e3,LOW);
    digitalWrite(e4,HIGH);
    digitalWrite(e5,HIGH);
    digitalWrite(e6,HIGH);
  }else if(module==4){
    digitalWrite(e1,HIGH);
    digitalWrite(e2,HIGH);
    digitalWrite(e3,HIGH);
    digitalWrite(e4,LOW);
    digitalWrite(e5,HIGH);
    digitalWrite(e6,HIGH);
  }else if(module==5){
    digitalWrite(e1,HIGH);
    digitalWrite(e2,HIGH);
    digitalWrite(e3,HIGH);
    digitalWrite(e4,HIGH);
    digitalWrite(e5,LOW);
    digitalWrite(e6,HIGH);
  }else if(module==6){
    digitalWrite(e1,HIGH);
    digitalWrite(e2,HIGH);
    digitalWrite(e3,HIGH);
    digitalWrite(e4,HIGH);
    digitalWrite(e5,HIGH);
    digitalWrite(e6,LOW);
  }

  ch0();
  delay(time_delay);
  ch1();
  delay(time_delay);
  ch2();
  delay(time_delay);
  ch3();
  delay(time_delay);
  ch4();
  delay(time_delay);
  ch5();
  delay(time_delay);
  ch6();
  delay(time_delay);
  ch7();
  delay(time_delay);
  ch8();
  delay(time_delay);
  ch9();
  delay(time_delay);
  ch10();
  delay(time_delay);
  ch11();
  delay(time_delay);
  ch12();
  delay(time_delay);
  ch13();
  delay(time_delay);
  ch14();
  delay(time_delay);
  ch15();
  delay(time_delay);
}
void loop() {
 multiplexer(1,100);
 multiplexer(2,100);
 multiplexer(3,100);
 multiplexer(4,100);
 multiplexer(5,100);
 multiplexer(6,100);
}