#define switch_1 1
#define adj_sw A0
#define max_del 500

int getdelay();

void setup() {
  pinMode(11,OUTPUT);
  pinMode(10,OUTPUT);
  pinMode(9,OUTPUT);
  pinMode(8,OUTPUT);
  pinMode(switch_1,INPUT);
  pinMode(adj_sw,INPUT);
}

void loop() {
  int val = getdelay();
  if(digitalRead(switch_1)==true){
    digitalWrite(11,HIGH);
    delay(val);
    digitalWrite(11,LOW);

    digitalWrite(10,HIGH);
    delay(val);
    digitalWrite(10,LOW);

    digitalWrite(9,HIGH);
    delay(val);
    digitalWrite(9,LOW);

    digitalWrite(8,HIGH);
    delay(val);
    digitalWrite(8,LOW);
  }
}
  int getdelay(){
double voltage = analogRead(adj_sw);
return voltage/1023*max_del;
  }