[Arduino IDE][AX-12A] Issues reading Present Position from AX-12A #66

t-kitajima · 2018-12-19T10:24:19Z

I tried to get the Present Position value of AX-12A by using Dynamixelworkbench, but it does not cause an error and the value is 0.
API of 1 can get the value with , but it could not get with API of 2.
What is the cause?
I will attach the log and code at that time.

1. bool readRegister (uint8_t id, uint16_t address, uint16_t length, uint32_t * data, const char ** log = NULL);
2. bool readRegister (uint8_t id, const char * item_name, int32_t * data, const char ** log = NULL);

Environment
OpenCM9.04, SMPS2Dynamixel, Arduino IDE 1.8.8, DynamixelWorkbench 1.3.0, Windows10

Dynamixel Setting

Model Name
AX-12A
ID
ID1
Baud Rate of Dynamixels
1000000
Protocol Version
Protocol1.0

code

#include <DynamixelWorkbench.h>

#define DEVICE_NAME "1"

#define BAUDRATE  1000000
#define DXL_ID_1  1

DynamixelWorkbench dxl_wb;

uint8_t dxl_id = DXL_ID_1;
uint16_t goal_position[2] = {0, 1023};
const uint8_t handler_index = 0;

void setup()
{
  Serial.begin(57600);
  while (!Serial); // Wait for Opening Serial Monitor

  const char *log;
  bool result = false;

  uint16_t model_number = 0;

  result = dxl_wb.init(DEVICE_NAME, BAUDRATE, &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to init");
  }
  else
  {
    Serial.print("Succeeded to init : ");
    Serial.println(BAUDRATE);
  }
  result = dxl_wb.ping(dxl_id, &model_number, &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to ping");
  }
  else
  {
    dxl_wb.torqueOn(dxl_id);
    Serial.println("Succeeded to ping");
    Serial.print("id : ");
    Serial.print(dxl_id);
    Serial.print(" model_number : ");
    Serial.println(model_number);
  }
}

void loop()
{
  const char *log;
  bool result = false;

  int32_t get_data = 0;

  // id , address , data_length , read_data, log
  result = dxl_wb.writeRegister(dxl_id, 30, 2, (uint8_t*)&goal_position[0], &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to write position");
  }
  else
  {
    Serial.println(log);
  }
  
  do
  {
    //result = dxl_wb.readRegister(dxl_id, 36 , 2, &get_data , &log);
    result = dxl_wb.readRegister(dxl_id, "Present_Position", &get_data , &log);
    if (result == false)
    {
      Serial.println(log);
    }
    else
    {
      Serial.print("[ID ");
      Serial.print(dxl_id);
      Serial.print(" ]");
      Serial.print(" Goal Position : ");
      Serial.print(goal_position[0]);
      Serial.print(" Present Position : ");
      Serial.println(get_data);
    }
  } while (abs(goal_position[0] - get_data) > 15);

  swapUint16(goal_position);
}

void swapUint16(uint16_t *array)
{
  uint16_t tmp = array[0];
  array[0] = array[1];
  array[1] = tmp;
}

log

Succeeded to init : 1000000
Succeeded to ping
id : 1 model_number : 12
[DynamixelDriver] Succeeded to write!
[ID 1 ] Goal Position : 0 Present Position : 0
[DynamixelDriver] Succeeded to write!
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
...

The text was updated successfully, but these errors were encountered:

routiful · 2018-12-19T12:12:33Z

You should torque on and set joint mode to your dynamixels
Add below code after Ping()

    result = dxl_wb.jointMode(dxl_id, 0, 0, &log);
    if (result == false)
    {
      printf("%s\n", log);
      printf("Failed to change joint mode\n");
    }
    else
    {
      printf("Succeed to change joint mode\n");
    }

t-kitajima · 2018-12-20T03:25:54Z

Does AX-12A not support jointMode?
Because it causes an error, torque is turned ON with "dxl_wb.torqueOn (dxl_id);" after ping.
I will also attach a log of errors.

log

Succeeded to init : 1000000
Succeeded to ping
id : 1 model_number : 12
[DynamixelWorkbench] Failed to set Joint Mode!
Failed to change joint mode
[DynamixelDriver] Succeeded to write!
[ID 1 ] Goal Position : 0 Present Position : 0
[DynamixelDriver] Succeeded to write!
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0
[ID 1 ] Goal Position : 1023 Present Position : 0

routiful · 2018-12-21T01:13:15Z

I have found terribly mistakes write and readRegister functions.
Please update your OpenCM version.

I give you to test code, too.

#include <DynamixelWorkbench.h>

#define DEVICE_NAME "1"

#define BAUDRATE  1000000
#define DXL_ID_1  1

DynamixelWorkbench dxl_wb;

uint8_t dxl_id = DXL_ID_1;
uint16_t goal_position[2] = {0, 1023};
const uint8_t handler_index = 0;

void setup()
{
  Serial.begin(57600);
  while (!Serial); // Wait for Opening Serial Monitor

  const char *log;
  bool result = false;

  uint16_t model_number = 0;

  result = dxl_wb.init(DEVICE_NAME, BAUDRATE, &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to init");
  }
  else
  {
    Serial.print("Succeeded to init : ");
    Serial.println(BAUDRATE);
  }
  
  result = dxl_wb.ping(dxl_id, &model_number, &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to ping");
  }
  else
  {
    Serial.println("Succeeded to ping");
    Serial.print("id : ");
    Serial.print(dxl_id);
    Serial.print(" model_number : ");
    Serial.println(model_number);
  }

  result = dxl_wb.jointMode(dxl_id, 0, 0, &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to set joint mode");
  }
  else
  {
    Serial.println("Succeeded to set joint mode");
  }
}

void loop()
{
  const char *log;
  bool result = false;

  int32_t get_data = 0;

  result = dxl_wb.writeRegister(dxl_id, "Goal_Position", goal_position[0], &log);
  if (result == false)
  {
    Serial.println(log);
    Serial.println("Failed to write position");
  }
  else
  {
    Serial.println(log);
  }
  
  do
  {
    result = dxl_wb.readRegister(dxl_id, "Present_Position", &get_data , &log);
    if (result == false)
    {
      Serial.println(log);
    }
    else
    {
      Serial.print("[ID ");
      Serial.print(dxl_id);
      Serial.print(" ]");
      Serial.print(" Goal Position : ");
      Serial.print(goal_position[0]);
      Serial.print(" Present Position : ");
      Serial.println(get_data);
    }
  } while (abs(goal_position[0] - get_data) > 15);

  swapUint16(goal_position);
}

void swapUint16(uint16_t *array)
{
  uint16_t tmp = array[0];
  array[0] = array[1];
  array[1] = tmp;
}

t-kitajima · 2018-12-21T04:06:09Z

I found the same bug yesterday.
Thanks for the measure of the bug.

I have an opinion on the modified code, where should I post?
modified write and read register

t-kitajima · 2018-12-21T04:09:01Z

It is the case that JointMode becomes an error,
I think the AX - 12A seems to be unable to set MovingSpeed unless the torque is ON.
Is this a specification?

routiful · 2018-12-21T04:24:57Z

You can comment code line in commit or use pull request with your opinion.

I have tested that code with new version and the test is successful

Succeeded to init : 1000000
Succeeded to ping
id : 2 model_number : 12
Succeeded to set joint mode
[DynamixelDriver] Succeeded to write!
[ID 2 ] Goal Position : 0 Present Position : 0
[DynamixelDriver] Succeeded to write!
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0
[ID 2 ] Goal Position : 1023 Present Position : 0

t-kitajima · 2018-12-21T04:33:17Z

It helped a lot.
I will write a comment in the code.
Thank you

OpusK assigned OpusK and routiful Dec 20, 2018

OpusK added the accepted label Dec 20, 2018

OpusK added in progress and removed accepted labels Dec 20, 2018

routiful mentioned this issue Dec 21, 2018

hotfix ROBOTIS-GIT/dynamixel-workbench#212

Merged

routiful added the bug label Dec 21, 2018

This was referenced Dec 21, 2018

Minor update ROBOTIS-GIT/OpenCR#154

Merged

modified write and read register functions #67

Merged

routiful mentioned this issue Jan 2, 2019

modified write register for AX comm and scan range ROBOTIS-GIT/dynamixel-workbench#215

Merged

OpusK closed this as completed Feb 20, 2019

OpusK removed the in progress label Feb 20, 2019

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[Arduino IDE][AX-12A] Issues reading Present Position from AX-12A #66

[Arduino IDE][AX-12A] Issues reading Present Position from AX-12A #66

t-kitajima commented Dec 19, 2018

routiful commented Dec 19, 2018

t-kitajima commented Dec 20, 2018

routiful commented Dec 21, 2018 •

edited

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t-kitajima commented Dec 21, 2018

t-kitajima commented Dec 21, 2018

routiful commented Dec 21, 2018

t-kitajima commented Dec 21, 2018

[Arduino IDE][AX-12A] Issues reading Present Position from AX-12A #66

[Arduino IDE][AX-12A] Issues reading Present Position from AX-12A #66

Comments

t-kitajima commented Dec 19, 2018

routiful commented Dec 19, 2018

t-kitajima commented Dec 20, 2018

routiful commented Dec 21, 2018 • edited Loading

t-kitajima commented Dec 21, 2018

t-kitajima commented Dec 21, 2018

routiful commented Dec 21, 2018

t-kitajima commented Dec 21, 2018

routiful commented Dec 21, 2018 •

edited

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