Running system call from simulink

I have tryed to implement a system call on simulink to execute a python script, using this solution, implemented on a Matlab system block:

System call from Simulink with external hardware (Raspberry PI)

So my files are like this:

python_script.m:

classdef python_script < matlab.System ...
        & coder.ExternalDependency ...
        & matlab.system.mixin.Propagates ...
        & matlab.system.mixin.CustomIcon
      properties
          % Public, tunable properties.
      end
      properties (Nontunable)
          % Public, non-tunable properties.
      end
      properties (Access = private)
          % Pre-computed constants.
      end
      methods
          % Constructor
          function obj = python_script_trigger(varargin)
              % Support name-value pair arguments when constructing the object.
              setProperties(obj,nargin,varargin{:});
          end
      end
      methods (Access=protected)
          function setupImpl(obj) %#ok<MANU>
          end
          function stepImpl(obj,turn_on)  %%#ok<INUSD>
              if isempty(coder.target)
                  % Place simulation output code here 
              else
                  % Call C-function implementing device output
                  coder.cinclude('python_script.h');
                  coder.ceval('python_script_command',turn_on);
              end
          end
          function releaseImpl(obj) %#ok<MANU>
              if isempty(coder.target)
                  % Place simulation termination code here
              else
                  % Call C-function implementing device termination
                  %coder.ceval('sink_terminate');
              end
          end
      end
      methods (Access=protected)
          %%Define input properties
          function num = getNumInputsImpl(~)
              num = 1;
          end
          function num = getNumOutputsImpl(~)
              num = 0;
          end
          function flag = isInputSizeLockedImpl(~,~)
              flag = true;
          end
          function varargout = isInputFixedSizeImpl(~,~)
              varargout{1} = true;
          end
          function flag = isInputComplexityLockedImpl(~,~)
              flag = true;
          end
          function icon = getIconImpl(~)
              % Define a string as the icon for the System block in Simulink.
              icon = 'python_script';
          end
      end
      methods (Static, Access=protected)
          function simMode = getSimulateUsingImpl(~)
              simMode = 'Interpreted execution';
          end
          function isVisible = showSimulateUsingImpl
              isVisible = false;
          end
      end
      methods (Static)
          function name = getDescriptiveName()
              name = 'python_script';
          end
          function b = isSupportedContext(context)
              b = context.isCodeGenTarget('rtw');
          end
          function updateBuildInfo(buildInfo, context)
              if context.isCodeGenTarget('rtw')
                 % Update buildInfo
                  srcDir = fullfile(fileparts(mfilename('fullpath')),'../src'); %%#ok<NASGU>
                  includeDir = fullfile(fileparts(mfilename('fullpath')),'../include');
                  addIncludePaths(buildInfo,includeDir);    
                  addSourceFiles(buildInfo,'python_script.c',srcDir);        
              end
          end
      end
 end

python_script.c

#include <python_script.h>
char command[512];
void python_script_command(boolean_T turn_on)
{
    if (turn_on == 1)
    {
        strcpy( command, "C:\ti\simplelink_cc13x2_26x2_sdk_5_10_00_48\tools\ble5stack\rtls_agent\.venv\Scripts\python C:\ti\simplelink_cc13x2_26x2_sdk_5_10_00_48\tools\ble5stack\rtls_agent\examples\rtls_aoa_iq_with_rtls_util_export_into_csv.py" );
        system(command);
    }
}

python_script.h

#ifndef _PYTHON_SCRIPT_H_
#define _PYTHON_SCRIPT_H_
#include "rtwtypes.h"
void python_script_command(boolean_T turn_on);
#endif //_PYTHON_SCRIPT_H_

Whenever I execute this script, it should create a log file, but when I execute it running simulink, it doesn't, so I suppose it is not working properly. Is there any other better solution or am I implementing this incorrectly?

I need the system call to start when I execute the simulink model (only once, and then the script should keep running), because I want to synchronize it with a csv reading script.

Answer 1

[Sergio Mesa Martín]

I found out it was as simple as this on a matlab function:

function fcn()
coder.extrinsic('system');
system(['C:\ti\simplelink_cc13x2_26x2_sdk_5_10_00_48\tools\' ...
'ble5stack\rtls_agent\.venv\Scripts\python C:\\ti\\simplelink_cc13x2'...
'_26x2_sdk_5_10_00_48\\tools\\ble5stack\\rtls_agent\\examples\\rtls_example_'...
'with_rtls_util.py'])
end

[Sergio Mesa Martín]

Anyway, I have doubts on how this works on simulink. When I execute the simulink model, it calls the system, but, does it call the system everytime while being executed or only once per run?

[Prasanth Sunkara]

Using MATLAB Function block was good choice.

It calls at every sample time. You can avoid that by using a persistent variable and call the system command only once based on whether the variable was intialized or not.

For more info check out: https://www.mathworks.com/help/simulink/ug/initialize-persistent-variables.html

Thanks,

Prasanth

[Prasanth Sunkara]

Or even better, you could place this system, cmd in the Model initialize function.

https://www.mathworks.com/help/simulink/ug/initialization-function.html