RAM control table changes with OpenCM9.04 and XL-320

seansies · November 22, 2021, 12:24pm

Hello,

I’m now moving these motors (thanks here - OpenCM9.04 and XL-320 motors not working - Hardware Support - ROBOTIS). But I have been unable to update PID gain values using the “writeControlTableItem” function. I’ve tried to set new values and read them back, but it returns 0 for all the PID values (according to the emanual, the default value for POSITION_P_GAIN is 32, but it returns 0 there as well). Anything I’m missing? I’ll post details and code below.

Thanks!

As before, I’m using:

2x XL-320 motors
OpenCM9.04 board, connected to PC via USB
Arduino IDE v1.8.13
OpenCM9.04 boards package v1.5.1
Dynamixel2Arduino library v0.5.1
no external power supply EDIT 7.4V supplied via bench power supply

Code I’ve been working from:

#include <Dynamixel2Arduino.h>

#define DXL_SERIAL   Serial1 //OpenCM9.04 EXP Board's DXL port Serial. (Serial1 for the DXL port on the OpenCM 9.04 board)
const uint8_t DXL_DIR_PIN = 28; //OpenCM9.04 EXP Board's DIR PIN. (28 for the DXL port on the OpenCM 9.04 board)
const float DXL_PROTOCOL_VERSION = 2.0;

#define MAX_BAUD  5
const int32_t buad[MAX_BAUD] = {57600, 115200, 1000000, 2000000, 3000000};

#define X_ID 1
#define Y_ID 2

// motors appear to have the center NEAR 512 units but not exactly
#define X_CENTER 520
#define Y_CENTER 526
const float UNITS_PER_DEG = 1024.0/280.0;

// set physical parameters
const float X_ARM_L = 11.0; // mm
const float Y_ARM_L = 16.0; // mm
const float X_MAX = 7.0; // mm
const float X_MIN = -7.0; // mm
const float Y_MAX = 12.0; // mm
const float Y_MIN = -12.0; // mm
const float XY_STEP_SIZE = 2.0 ; // mm

float xTarget = 0.0; // mm, range
float yTarget = 0.0; // mm, range
float xCommand = X_CENTER; // dynamixel step
float yCommand = Y_CENTER; // dynamixel step

Dynamixel2Arduino dxl(DXL_SERIAL, DXL_DIR_PIN);

//This namespace is required to use Control table item names
using namespace ControlTableItem;

void setup() {
  // put your setup code here, to run once:
  int8_t index = 0;
  int8_t found_dynamixel = 0;

  // Use UART port of DYNAMIXEL Shield to debug.
  Serial.begin(115200);   //set debugging port baudrate to 115200bps
  while(!Serial);         //Wait until the serial port is opened

//  // scan for connected motors
//  // this can be removed when code is more complete
//  for(int8_t protocol = 1; protocol < 3; protocol++) {
//    // Set Port Protocol Version. This has to match with DYNAMIXEL protocol version.
//    dxl.setPortProtocolVersion((float)protocol);
//    Serial.print("SCAN PROTOCOL ");
//    Serial.println(protocol);
//    
//    for(index = 0; index < MAX_BAUD; index++) {
//      // Set Port baudrate.
//      Serial.print("SCAN BAUDRATE ");
//      Serial.println(buad[index]);
//      dxl.begin(buad[index]);
//      for(int id = 0; id < DXL_BROADCAST_ID; id++) {
//        //iterate until all ID in each buadrate is scanned.
//        if(dxl.ping(id)) {
//          Serial.print("ID : ");
//          Serial.print(id);
//          Serial.print(", Model Number: ");
//          Serial.println(dxl.getModelNumber(id));
//          found_dynamixel++;
//        }
//      }
//    }
//  } // end scan routine

  // Set Port baudrate to 1Mbps. This has to match with DYNAMIXEL baudrate.
  dxl.begin(1000000);
  // Set Port Protocol Version. This has to match with DYNAMIXEL protocol version.
  dxl.setPortProtocolVersion(DXL_PROTOCOL_VERSION);

  // Turn off torque when configuring items in EEPROM area
  //   using position mode for now
  dxl.torqueOff(X_ID);
  dxl.torqueOff(Y_ID);
  dxl.setOperatingMode(X_ID, OP_POSITION);
  dxl.setOperatingMode(Y_ID, OP_POSITION);
  dxl.torqueOn(X_ID);
  dxl.torqueOn(Y_ID);
  
  // Limit the maximum velocity in Position Control Mode. Use 0 for Max speed
  dxl.writeControlTableItem(PROFILE_VELOCITY, X_ID, 0);
  dxl.writeControlTableItem(PROFILE_VELOCITY, Y_ID, 0);

  // mess with PID values
  //  27   1   D Gain  Derivative Gain   RW  0   0   254
  //  28   1   I Gain  Integral Gain     RW  0   0   254
  //  29   1   P Gain  Proportional Gain RW  32  0   254
  dxl.writeControlTableItem(POSITION_P_GAIN, X_ID, 32); delay(500);
  dxl.writeControlTableItem(POSITION_I_GAIN, X_ID, 1); delay(500);
  dxl.writeControlTableItem(POSITION_D_GAIN, X_ID, 1); delay(500);
   
  // check PID values
  Serial.print("XP "); Serial.println(dxl.readControlTableItem(POSITION_P_GAIN, X_ID)); delay(500);
  Serial.print("XI "); Serial.println(dxl.readControlTableItem(POSITION_I_GAIN, X_ID)); delay(500);
  Serial.print("XD "); Serial.println(dxl.readControlTableItem(POSITION_D_GAIN, X_ID)); delay(500);
  Serial.print("YP "); Serial.println(dxl.readControlTableItem(POSITION_P_GAIN, Y_ID)); delay(500);
  Serial.print("YI "); Serial.println(dxl.readControlTableItem(POSITION_I_GAIN, Y_ID)); delay(500);
  Serial.print("YD "); Serial.println(dxl.readControlTableItem(POSITION_D_GAIN, Y_ID)); delay(500);
  Serial.print("X_TORQUE_LIMIT "); Serial.println(dxl.readControlTableItem(TORQUE_LIMIT, X_ID)); delay(500);
  Serial.print("Y_TORQUE_LIMIT "); Serial.println(dxl.readControlTableItem(TORQUE_LIMIT, Y_ID)); delay(500);
  Serial.print("X_CURRENT_LIMIT "); Serial.println(dxl.readControlTableItem(CURRENT_LIMIT, X_ID)); delay(500);
  Serial.print("Y_CURRENT_LIMIT "); Serial.println(dxl.readControlTableItem(CURRENT_LIMIT, Y_ID)); delay(500);


  // I think it might need a moment to set the torque on, or something
  delay(50);

  // move both motors to center positions
  dxl.setGoalPosition(X_ID,X_CENTER);
  delay(1000); // time to reach position
  dxl.setGoalPosition(Y_ID,Y_CENTER);
  delay(1000); // time to reach position
  
}

void loop() {
  // print current position
//  Serial.print("X pos: "); Serial.print(dxl.getPresentPosition(X_ID)); Serial.print("\t");
//  Serial.print("Y pos: "); Serial.print(dxl.getPresentPosition(Y_ID)); Serial.print("\t");
//  Serial.print("\n");
  
//  dxl.setGoalPosition(X_ID,X_CENTER + UNITS_PER_DEG*45.0);
//  delay(1000);
//  dxl.setGoalPosition(X_ID,X_CENTER - UNITS_PER_DEG*45.0);
//  delay(1000);
//  dxl.setGoalPosition(Y_ID,Y_CENTER + UNITS_PER_DEG*45.0);
//  delay(1000);
//  dxl.setGoalPosition(Y_ID,Y_CENTER - UNITS_PER_DEG*45.0);
//  delay(1000);

    // see if user input anything in serial monitor
  if (Serial.available() > 0) {
    char userInput = Serial.read();
    if (userInput == 'a') {
      // nudge left (+x)
      xTarget += XY_STEP_SIZE;
    } else if (userInput == 'd') {
      // nudge right (-x)
      xTarget -= XY_STEP_SIZE;
    } else if (userInput == 'w') {
      // nudge forward (+y)
      yTarget += XY_STEP_SIZE;
    } else if (userInput == 's') {
      // nudge backward (-y)
      yTarget -= XY_STEP_SIZE;
    } else {
      Serial.println("Only accepting 'wasd' keyboard input.");
    }
    while(Serial.available()){Serial.read();}  // make sure the buffer is empty
  }

  // check that values are acceptable
  if (xTarget > X_MAX) { xTarget = X_MAX; Serial.println("X_MAX limit."); }
  if (xTarget < X_MIN) { xTarget = X_MIN; Serial.println("X_MIN limit."); }
  if (yTarget > Y_MAX) { yTarget = Y_MAX; Serial.println("Y_MAX limit."); }
  if (yTarget < Y_MIN) { yTarget = Y_MIN; Serial.println("Y_MIN limit."); }
  
  // convert xTarget and yTarget to xCommand (dynamixel unit) and yCommand
  xCommand = round( degrees(asin(xTarget/X_ARM_L)) * UNITS_PER_DEG + X_CENTER );
  yCommand = round( degrees(asin(yTarget/Y_ARM_L)) * UNITS_PER_DEG + Y_CENTER );

  // move
  dxl.setGoalPosition(X_ID,xCommand);   
  delay(100);
  dxl.setGoalPosition(Y_ID,yCommand);
  delay(100);

  Serial.print("Targets (x,y): "); Serial.print(xTarget); Serial.print(", "); Serial.print(yTarget); Serial.print("\t");
  Serial.print("Command (x,y): "); Serial.print(xCommand); Serial.print(", "); Serial.print(yCommand); Serial.print("\t"); 
  Serial.print("Current (x,y): "); Serial.print(dxl.getPresentPosition(X_ID)); Serial.print(", "); Serial.println(dxl.getPresentPosition(Y_ID));
//  delay(100);




}

And a sample of the output in the following post!

seansies · November 22, 2021, 1:01pm

I was being a dummy re: poor accuracy so will edit the title. With the setup connected to external power, the performance is significantly better (will post some output below). However I still don’t know how to set gain values, so any help there would be greatly appreciated!

XP 0
XI 0
XD 0
YP 0
YI 0
YD 0
X_TORQUE_LIMIT 1023
Y_TORQUE_LIMIT 1023
X_CURRENT_LIMIT 0
Y_CURRENT_LIMIT 0
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.00	Command (x,y): 520.00, 526.00	Current (x,y): 518.00, 526.00
Targets (x,y): 0.00, 0.50	Command (x,y): 520.00, 533.00	Current (x,y): 518.00, 528.00
Targets (x,y): 0.00, 0.50	Command (x,y): 520.00, 533.00	Current (x,y): 518.00, 530.00
Targets (x,y): 0.00, 0.50	Command (x,y): 520.00, 533.00	Current (x,y): 518.00, 530.00
Targets (x,y): 0.00, 0.50	Command (x,y): 520.00, 533.00	Current (x,y): 518.00, 530.00
Targets (x,y): 0.00, 1.00	Command (x,y): 520.00, 539.00	Current (x,y): 518.00, 536.00
Targets (x,y): 0.00, 1.00	Command (x,y): 520.00, 539.00	Current (x,y): 518.00, 536.00
Targets (x,y): 0.00, 1.00	Command (x,y): 520.00, 539.00	Current (x,y): 518.00, 536.00
Targets (x,y): 0.00, 1.00	Command (x,y): 520.00, 539.00	Current (x,y): 518.00, 536.00
Targets (x,y): 0.00, 1.50	Command (x,y): 520.00, 546.00	Current (x,y): 518.00, 542.00
Targets (x,y): 0.00, 1.50	Command (x,y): 520.00, 546.00	Current (x,y): 518.00, 543.00
Targets (x,y): 0.00, 1.50	Command (x,y): 520.00, 546.00	Current (x,y): 517.00, 543.00
Targets (x,y): 0.00, 2.00	Command (x,y): 520.00, 552.00	Current (x,y): 518.00, 548.00
Targets (x,y): 0.00, 2.00	Command (x,y): 520.00, 552.00	Current (x,y): 518.00, 549.00
Targets (x,y): 0.00, 2.00	Command (x,y): 520.00, 552.00	Current (x,y): 518.00, 550.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 518.00, 556.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 518.00, 556.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 518.00, 556.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 518.00, 556.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 518.00, 556.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 518.00, 556.00
Targets (x,y): 0.50, 2.50	Command (x,y): 530.00, 559.00	Current (x,y): 527.00, 556.00
Targets (x,y): 0.50, 2.50	Command (x,y): 530.00, 559.00	Current (x,y): 528.00, 556.00
Targets (x,y): 1.00, 2.50	Command (x,y): 539.00, 559.00	Current (x,y): 537.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.50, 2.50	Command (x,y): 549.00, 559.00	Current (x,y): 547.00, 556.00
Targets (x,y): 1.00, 2.50	Command (x,y): 539.00, 559.00	Current (x,y): 539.00, 556.00
Targets (x,y): 0.50, 2.50	Command (x,y): 530.00, 559.00	Current (x,y): 530.00, 556.00
Targets (x,y): 0.50, 2.50	Command (x,y): 530.00, 559.00	Current (x,y): 530.00, 556.00
Targets (x,y): 0.00, 2.50	Command (x,y): 520.00, 559.00	Current (x,y): 520.00, 556.00
Targets (x,y): -0.50, 2.50	Command (x,y): 510.00, 559.00	Current (x,y): 509.00, 556.00
Targets (x,y): -0.50, 2.50	Command (x,y): 510.00, 559.00	Current (x,y): 509.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00
Targets (x,y): -1.00, 2.50	Command (x,y): 501.00, 559.00	Current (x,y): 500.00, 556.00

roboteer · November 23, 2021, 4:15am

@seansies
I think that you may have used the wrong Control Table Items, the XL-320 is a much older actuator and it has this Control Table Info as shown below:

The other newer XL actuators like 330 and 430 use this Control Table Info

In other words, please try to use MOVING_SPEED instead of PROFILE_VELOCITY, P_GAIN instead of POSITION_P_GAIN, etc.

For more details, please download the actual source code for the Dynamixel2Arduino library from the ROBOTIS GitHub (GitHub - ROBOTIS-GIT/Dynamixel2Arduino: DYNAMIXEL protocol library for Arduino). Unzip this file and find the source code named “actuator.cpp” which has all the details that I extracted out in my previous two screenshots.

Also, you may be already familiar with the e-manual info for the Control Table for the XL-320 which is at (XL-320).

Lastly, I would recommend to recover the firmware on your XL-320s as you had been writing into Control Table Addresses that you did not mean to, just to get the XL-320s “back to normal” and to be on the safe side.

seansies · November 23, 2021, 11:07am

Right thank you @roboteer !

Is there a quick way to recover the firmware?

roboteer · November 23, 2021, 10:51pm

@seansies
I would restore the ROBOTIS firmware back onto the OpenCM-904 first, so that you can use the MANAGER tool (if you have a Windows PC). Then from the MANAGER tool, you can recover the XL-320’s firmware ONE by ONE (via the OpenCM-904 board).

Yogurt_Man · November 29, 2021, 8:52am

@seansies,

To add up information to @roboteer’s advice,

See OpenCM 485 EXP

Although the e-Manual I shared is linked for the OpenCM485 EXP board (OpenCM 9.04 interface)
you can follow the steps exactly same.

Hope your projects going well.