#define LED0 A0
#define LED1 A1
#define LED2 A2
#define LED3 A3


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hi");
  pinMode(A0, OUTPUT);
  pinMode(A1, OUTPUT);
  pinMode(A2, OUTPUT);
  pinMode(A3, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available()){
    char c = Serial.read();
     if (c == '1') {
      digitalWrite(LED0, HIGH);
      digitalWrite(LED1, LOW);
      digitalWrite(LED2, HIGH);
      digitalWrite(LED3, LOW);
    } 

     else if (c == '2') {
      digitalWrite(LED0, LOW);
      digitalWrite(LED1, HIGH);
      digitalWrite(LED2, LOW);
      digitalWrite(LED3, HIGH);
    }

    else if (c == '3') {
      digitalWrite(LED0, HIGH);
      digitalWrite(LED1, HIGH);
      digitalWrite(LED2, HIGH);
      digitalWrite(LED3, HIGH);
    }

    else if (c == '4') {
      digitalWrite(LED0, LOW);
      digitalWrite(LED1, LOW);
      digitalWrite(LED2, LOW);
      digitalWrite(LED3, LOW);
    }
  }
}