Not allow anti rotation in current mode

[hhcheng13]

It does not allow to send the negative current in current control mode. It return: Error using calllib Value exceeds the legal range for the data type.

[geoand-robotdesign]

Hello, Are you maybe using int16 instead of uint16 to send the current to the Write blocks? Please note that Dynamixel handles these values as unsigned integers, so uint16 needs to be used for the current (since it is 2 bytes). Best Regards, Georgios Andrikopoulos ***@***.*** Georgios Andrikopoulos Assistant Professor in Mechatronics with focus on Robot Design KTH Royal Institute of Technology Engineering Design Department / Mechatronics Unit / Robot Design Laboratory Brinnellvägen 83, SE-114 28 Stockholm, Sweden Phone: +46-8-790 63 31 ***@***.******@***.***>, https://www.kth.se/profile/geoand?l=en From: hhcheng13 ***@***.***> Sent: Thursday, April 18, 2024 7:08 PM To: geoand-robotdesign/Dynamixel_Library_MATLAB_Simulink ***@***.***> Cc: Subscribed ***@***.***> Subject: [geoand-robotdesign/Dynamixel_Library_MATLAB_Simulink] Not allow anti rotation in current mode (Issue #2) It does not allow to send the negative current in current control mode. It return: Error using calllib Value exceeds the legal range for the data type. — Reply to this email directly, view it on GitHub<#2>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AZEBEVKXLDFKUHP2EHYCYM3Y574XDAVCNFSM6AAAAABGNWAEQOVHI2DSMVQWIX3LMV43ASLTON2WKOZSGI2TCMJXGM2TQOI>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[hhcheng13]

Thanks for the reply=). I am not sure if I do it correctly. I use the SyncReadSyncWrite.m and modify the

group_num_write = initSyncWriteDxl(lib_name, port_num, protocol_version,...
motor_models, ["Goal Position"; "Goal Velocity"]);
...
syncWriteDxl(lib_name, group_num_write(1), motor_IDs, motor_models, ...
data, 'Goal Position')

into

group_num_write = initSyncWriteDxl(lib_name, port_num, protocol_version,...
motor_models, ["Goal Position"; "Goal Velocity"; "Goal Current"]);
...
syncWriteDxl(lib_name, group_num_write(2), motor_IDs, motor_models, ...
-5*ones(numel(motor_IDs),1), 'Goal Current')

Then it returns "Value exceeds the legal range for the data type."

[geoand-robotdesign]

Hello, From the code snippet you provided, I see that group_num_write(1) becomes group_num_write(2), although index 2 belongs to velocity in your code. Please try group_num_write(3), which corresponds to current, and see if that fixes the issue. I cannot see anything else wrong, from what I understand you are trying to send the value -5 to all motors, which should be well within the [-Current Limit, +Current Limit] range set by default in most (if not all) Dynamixel models. Checking your motors in Dynamixel Wizard should verify whether you are indeed in range. If the issue persists, I will need more information about which motor you are using, to see if my team can replicate the error and provide more assistance.

…

-- Best Regards Georgios <tel:+4687906331>

________________________________ From: hhcheng13 ***@***.***> Sent: Friday, April 19, 2024 4:54:32 pm To: geoand-robotdesign/Dynamixel_Library_MATLAB_Simulink ***@***.***> Cc: Georgios Andrikopoulos ***@***.***>; Comment ***@***.***> Subject: Re: [geoand-robotdesign/Dynamixel_Library_MATLAB_Simulink] Not allow anti rotation in current mode (Issue #2) Thanks for the reply=). I am not sure if I do it correctly. I use the SyncReadSyncWrite.m and modify the group_num_write = initSyncWriteDxl(lib_name, port_num, protocol_version,... motor_models, ["Goal Position"; "Goal Velocity"]); ... syncWriteDxl(lib_name, group_num_write(1), motor_IDs, motor_models, ... data, 'Goal Position') into group_num_write = initSyncWriteDxl(lib_name, port_num, protocol_version,... motor_models, ["Goal Position"; "Goal Velocity"; "Goal Current"]); ... syncWriteDxl(lib_name, group_num_write(2), motor_IDs, motor_models, ... -5*ones(numel(motor_IDs),1), 'Goal Current') Then it returns "Value exceeds the legal range for the data type." — Reply to this email directly, view it on GitHub<#2 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AZEBEVMAM62WEIRF5GOYSHTY6EV2LAVCNFSM6AAAAABGNWAEQOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDANRWG42TANRZGQ>. You are receiving this because you commented.Message ID: ***@***.***>

[Ki-wano-enca]

Hello,

I'm facing the same problem.
The code is a simple one like the following, which is a modified version of the 'ReadWrite' protocol 2.0 for current control.

`
clear
close all
clc

% Set COM port
com_port = 'COM8';

% Set baudrate
baud_rate = 4000000;
baud_rate = 57600;

% Set protocol Version
protocol_version = 2;

% Initialize library and port number
[lib_name, port_num] = initDxl(com_port);

% Open port
openPortDxl(lib_name, port_num);

% Set Baudrate
setBaudDxl(lib_name, port_num, baud_rate);

% Find dynamixels
[motor_IDs, motor_models] = findDxl(lib_name, port_num, protocol_version);

% Operating modes
% operatingModeDxl(lib_name, port_num, protocol_version, motor_IDs, ...
% motor_models, 'Extended Position Control');
operatingModeDxl(lib_name, port_num, protocol_version, motor_IDs, ...
motor_models, 'Current Control');

% Drive modes
driveModeDxl(lib_name, port_num, protocol_version, motor_IDs, ...
motor_models, 'Velocity-based Profile');

% Enable torque
torqueDxl(lib_name, port_num, protocol_version, motor_IDs, ...
motor_models, 'Enable');

% Check error
checkErrorDxl(lib_name, port_num, protocol_version)

%% Example
% clc

% Data to write
data = 2000; % Example goal position for one motor
data = -2000; % Example goal position for one motor
% data = uint16(-2000); % Example goal current for one motor [mA] 2047->5506.43mA
% data = [2000 1000]; % Example goal position for two motors

% Write function
tic
% writeDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
% data, 'Goal Position')
writeDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
data, 'Goal Current')
toc

% Read functions
tic
readDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
'Present Position')
readDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
'Present Velocity')
readDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
'Present Current/Load')
readDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
'Present Temperature')
toc
%% End Session
% clc

% Disable torque
torqueDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
'Disable');

% Check error
checkErrorDxl(lib_name, port_num, protocol_version)

% Close port
closePortDxl(lib_name,port_num);
`

If I set the goal current to a negative value with this code, the following error will occur.
There seems to be a problem with the part that uses callib.

`
Error while using: calllib
The value exceeds the valid range of the data type.

Error: writeDxl (line 32)
calllib(lib_name, func, port_num, protocol_version, ids(index), ...

Error: ReadWrite_currentcontrol (line 70)
writeDxl(lib_name, port_num, protocol_version, motor_IDs, motor_models, ...
`

It may be necessary to change the contents of writeDxl (a method that does not use callib or consider write2ByteTxRx).
I would appreciate it if you could suggest a revision of the code, etc.

Also, as a supplementary note, it seems that the values specified here correspond to the Decimal value in the Dynamixel wizard.

[Ki-wano-enca]

I solved it myself like the code below.

`
% Data to write
max_uint16 = intmax('uint16');

data = 2000; % Example goal position for one motor

if data<0

data = max_uint16-2010; % Example goal position for one motor

end
`