#include <Servo.h>

Servo servo1;
Servo servo2;
Servo servo3;
Servo servo4;

void setup() {
  servo1.attach(2);
  servo2.attach(3);
  servo3.attach(4);
  servo4.attach(5);

  servo1.write(90);
  servo2.write(90);
  servo3.write(90);
  servo4.write(90);

  Serial.begin(9600);
  while (!Serial) {
    ;
  }
}

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

    switch (comando) {
      case '1':
        servo1.write(0);
        break;
      case '2':
        servo1.write(90);
        break;
      case '3':
        servo1.write(180);
        break;
      case '4':
        servo2.write(0);
        break;
      case '5':
        servo2.write(90);
        break;
      case '6':
        servo2.write(180);
        break;
      case '7':
        servo3.write(0);
        break;
      case '8':
        servo3.write(90);
        break;
      case '9':
        servo3.write(180);
        break;
      case 'a':
        servo4.write(0);
        break;
      case 'b':
        servo4.write(90);
        break;
      case 'c':
        servo4.write(180);
        break;
      default:
        break;
    }
  }
}