communication problem with dynamixel AX12-A

Hi everybody,

i’m new in the forum so i apologize if this is not the correct place for the thread.

The thing is i’m trying to program some dynamixels AX-12A. (I have 5 in my possession now)

One of them is working properly and I can use it without problem.

The thing is I can’t communicate with the others (all of them have been used before so maybe the ID number is changed). So i try to reset them with the function


since 254 seems to be the number to access all the AX.12A, and i also tried it with:

for (int i=0; i<255; i++){

The one i can communicate with resets with this commands (i know it because the leds blink when you reset them), but i’m not able to reset the others.

Currently im using a baud rate of 1x10^6. Can it be a baud rate problem?

Is there a way to “protect from resets”, so they may have been protected before I got them?

I runned out of ideas and I have no clue how to solve this.

The code i’m using is:

#include <DynamixelSerial.h>

void setup(){

for (int i=0; i<255; i++){
//for (int i=0; i<254; i++){
// Dynamixel.ledStatus(1,ON);


void loop(){

//Dynamixel.moveSpeed(1,512, 750); // Mueve el Servo a la Posición 750 con una Velocidad de 1023
//Dynamixel.moveSpeed(1,1023, 750);

Dynamixel.moveSpeed(254,200, 750);
Dynamixel.moveSpeed(254,800, 750);