   Serial.print("Y = "),Serial.print(map(analogRead(yAxisId), 0, 1023, -1, 1));Serial.print("\n");
 }
 
-void updateServo(int axis_id, Servo* servo) {
-  int val = analogRead(axis_id);            // reads the value of the potentiometer (value between 0 and 1023)
-  val = map(val, 0, 1023, 0, 180);     // scale it to use it with the servo (value between 0 and 180)
-  servo->write(val);
+void update_servo(int axis_id, Servo* servo) {
+  int val = analogRead(axis_id);
+  val = map(val, 0, 1023, -100, 100);
+  int final_val = val / 10;
+  servo->write(servo->read() + final_val);
+}
+
+void update_servos_pair() {
+  int base_servo_index = current_pair_selection * 2;
+  update_servo(x_axis, &servos[base_servo_index]);
+  update_servo(y_axis, &servos[base_servo_index + 1]);
+}
+
+void read_servos_pair_selection() {
+  int selection = digitalRead(boton_cambios);
+  if (selection == LOW) {
+    current_pair_selection = (current_pair_selection + 2) % servos_quantity;
+    if (DEBUG) {
+      Serial.print("Par de servos: "),Serial.print(current_pair_selection),Serial.print("\n");
+    }
+  }
 }
 
 void loop() {
-  printButton("UP", up_button);
-  printButton("DOWN", down_button);
-  printButton("LEFT", left_button);
-  printButton("RIGHT", right_button);
-  printButton("START", start_button);
-  printButton("SELECT", select_button);
-  printButton("ANALOG", analog_button);
-  printButton("X", start_button);
-  printJoystick(x_axis, y_axis);
-  updateServo(x_axis, &servo_base);
-  updateServo(y_axis, &servo_tronco);
-  
-  delay(100);
+  update_servos_pair();
+  read_servos_pair_selection();
+  delay(150);
 }
 
 

Servo servo_tronco;
Servo servo_trompa;
Servo servo_pinza;

/* ***************************************************************************************
 *                                         SETUP                                         *
 * ***************************************************************************************/
void init_buttons() {
  for (int i; i < buttons_quantity; i++) {
   pinMode(buttons[i], INPUT_PULLUP);
  }
}

#include <Servo.h>

bool DEBUG = true;

/* ***************************************************************************************
 *                                      PINES BOTONERA                                   *
 * ***************************************************************************************/
const int up_button = 2;
const int down_button = 4;
const int left_button = 5;
const int right_button = 3;
const int start_button = 6;
const int select_button = 7;
const int analog_button = 8;
const int x_axis = A0;
const int y_axis = A1;
const int buttons[] = {up_button, down_button, left_button, right_button, start_button, select_button, analog_button};
const int buttons_quantity = 7;

/* ***************************************************************************************
 *                                     MAPEO A FUNCIONES                                 *
