Sync Write ax18 not working in OpenCM 9.04 with dynamixel2arduino

[syakirahmd]

hi,

I am trying to sync write a goal position into 2 different servos. this is the code I am using

#include <Dynamixel2Arduino.h>

// Please modify it to suit your hardware.
#if defined(ARDUINO_AVR_UNO) || defined(ARDUINO_AVR_MEGA2560) // When using DynamixelShield
  #include <SoftwareSerial.h>
  SoftwareSerial soft_serial(7, 8); // DYNAMIXELShield UART RX/TX
  #define DXL_SERIAL   Serial
  #define DEBUG_SERIAL soft_serial
  const uint8_t DXL_DIR_PIN = 2; // DYNAMIXEL Shield DIR PIN
#elif defined(ARDUINO_SAM_DUE) // When using DynamixelShield
  #define DXL_SERIAL   Serial
  #define DEBUG_SERIAL SerialUSB
  const uint8_t DXL_DIR_PIN = 2; // DYNAMIXEL Shield DIR PIN
#elif defined(ARDUINO_SAM_ZERO) // When using DynamixelShield
  #define DXL_SERIAL   Serial1
  #define DEBUG_SERIAL SerialUSB
  const uint8_t DXL_DIR_PIN = 2; // DYNAMIXEL Shield DIR PIN
#elif defined(ARDUINO_OpenCM904) // When using official ROBOTIS board with DXL circuit.
  #define DXL_SERIAL   Serial3 //OpenCM9.04 EXP Board's DXL port Serial. (Serial1 for the DXL port on the OpenCM 9.04 board)
  #define DEBUG_SERIAL Serial
  const uint8_t DXL_DIR_PIN = 22; //OpenCM9.04 EXP Board's DIR PIN. (28 for the DXL port on the OpenCM 9.04 board)
#elif defined(ARDUINO_OpenCR) // When using official ROBOTIS board with DXL circuit.
  // For OpenCR, there is a DXL Power Enable pin, so you must initialize and control it.
  // Reference link : https://github.com/ROBOTIS-GIT/OpenCR/blob/master/arduino/opencr_arduino/opencr/libraries/DynamixelSDK/src/dynamixel_sdk/port_handler_arduino.cpp#L78
  #define DXL_SERIAL   Serial3
  #define DEBUG_SERIAL Serial
  const uint8_t DXL_DIR_PIN = 84; // OpenCR Board's DIR PIN.    
#else // Other boards when using DynamixelShield
  #define DXL_SERIAL   Serial1
  #define DEBUG_SERIAL Serial
  const uint8_t DXL_DIR_PIN = 2; // DYNAMIXEL Shield DIR PIN
#endif

ParamForSyncWriteInst_t sync_write_param;
int32_t set_position = 512;
const float DXL_PROTOCOL_VERSION = 1.0;
Dynamixel2Arduino dxl(DXL_SERIAL, DXL_DIR_PIN);

void setup() {
  dxl.begin(1000000);
  dxl.setPortProtocolVersion(DXL_PROTOCOL_VERSION);
  dxl.scan();

  sync_write_param.addr = 30; //Goal position of DYNAMIXEL-AX series
  sync_write_param.length = 4;
  sync_write_param.xel[0].id = 1;
  sync_write_param.xel[1].id = 2;
  sync_write_param.id_count = 2;

  dxl.torqueOff(1);
  dxl.setOperatingMode(1, OP_POSITION);
  dxl.torqueOn(1);
  dxl.torqueOff(2);
  dxl.setOperatingMode(2, OP_POSITION);
  dxl.torqueOn(2);
  memcpy(sync_write_param.xel[0].data, (uint8_t*)set_position, sizeof(set_position));
  memcpy(sync_write_param.xel[1].data, (uint8_t*)-set_position,sizeof(set_position));

  dxl.syncWrite(sync_write_param);
}

void loop() {

}

could you tell me where is the wrong part. thanks in advance