int pinA = 2;
int pinB = 3;
int pinC = 4;
int pinD = 5;
int pinE = 6;
int pinF = 7;
int pinG = 8;

void setup() {
  pinMode(pinA, OUTPUT);
  pinMode(pinB, OUTPUT);
  pinMode(pinC, OUTPUT);
  pinMode(pinD, OUTPUT);
  pinMode(pinE, OUTPUT);
  pinMode(pinF, OUTPUT);
  pinMode(pinG, OUTPUT);
  
  Serial.begin(9600); 
  Serial.println("Escribe un numero del 0 al 9:");
}

void loop() {
  if (Serial.available() > 0) {
    char numero = Serial.read();

    if (numero == '0' || numero == '1' || numero == '2' || numero == '3' || 
        numero == '4' || numero == '5' || numero == '6' || numero == '7' || 
        numero == '8' || numero == '9') {
      
      digitalWrite(pinA, LOW);
      digitalWrite(pinB, LOW);
      digitalWrite(pinC, LOW);
      digitalWrite(pinD, LOW);
      digitalWrite(pinE, LOW);
      digitalWrite(pinF, LOW);
      digitalWrite(pinG, LOW);

      if (numero == '0') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinC, HIGH);
        digitalWrite(pinD, HIGH);
        digitalWrite(pinE, HIGH);
        digitalWrite(pinF, HIGH);
      } 
      else if (numero == '1') {
        digitalWrite(pinB, HIGH);
        digitalWrite(pinC, HIGH);
      } 
      else if (numero == '2') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinG, HIGH);
        digitalWrite(pinE, HIGH);
        digitalWrite(pinD, HIGH);
      } 
      else if (numero == '3') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinG, HIGH);
        digitalWrite(pinC, HIGH);
        digitalWrite(pinD, HIGH);
      } 
      else if (numero == '4') {
        digitalWrite(pinF, HIGH);
        digitalWrite(pinG, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinC, HIGH);
      } 
      else if (numero == '5') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinF, HIGH);
        digitalWrite(pinG, HIGH);
        digitalWrite(pinC, HIGH);
        digitalWrite(pinD, HIGH);
      } 
      else if (numero == '6') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinF, HIGH);
        digitalWrite(pinG, HIGH);
        digitalWrite(pinE, HIGH);
        digitalWrite(pinD, HIGH);
        digitalWrite(pinC, HIGH);
      } 
      else if (numero == '7') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinC, HIGH);
      } 
      else if (numero == '8') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinC, HIGH);
        digitalWrite(pinD, HIGH);
        digitalWrite(pinE, HIGH);
        digitalWrite(pinF, HIGH);
        digitalWrite(pinG, HIGH);
      } 
      else if (numero == '9') {
        digitalWrite(pinA, HIGH);
        digitalWrite(pinB, HIGH);
        digitalWrite(pinC, HIGH);
        digitalWrite(pinD, HIGH);
        digitalWrite(pinF, HIGH);
        digitalWrite(pinG, HIGH);
      }
    }
  }
}