Connection of BLE device with Simulink

Hello everyone,

I have already connected my BLE device with Matlab. I can read the heart rate. My problem ist, that I want to use the heart rate in desktop real time sumulation. How can I import this data in Simulink?

Thank you for your help.

Lucas

Answer 1

[Stefanie Schwarz]

Hi Lucas,

as far as I am aware, there is currently no Simulink block that can directly read from a BLE device using the host PC interface.

What you can do instead is use a MATLAB Function Block that leverages the ble() MATLAB function. The code would be along the lines of:

function y = fcn()    
    persistent b;    %automatically initialized to []
    persistent hr;   %automatically initialized to []
    
    %% extrinsic declarations
    coder.extrinsic('ble');
    coder.extrinsic('characteristic');
    coder.extrinsic('read');

    if(isempty(b))
        b = ble("UA E39 MODULE");
        hr = characteristic(b, "heart rate", "heart rate measurement");
    end
    
    %% initialize output
    y = zeros(...)
    %% read data from BLE device
    data = read(hr);
    %% post-process the data
    y = ...
end   

Note that the 'ble'-related functions do not support code generation and therefore need to be declared as extrinsic. Because of this, I am afraid you will not be able to run your model in a Simulink Desktop Real-Time (SLDRT) external mode simulation. However, you can run a SLDRT normal mode simulation which is a little different. To learn more about the differences between the two SLDRT simulation modes, see the following article:

https://www.mathworks.com/matlabcentral/answers/536647-what-is-the-difference-between-normal-accelerator-and-external-mode-when-using-simulink-desktop-rea

Another option if you are only looking for a simulation running at an approximation of the wall clock time would be Simulation Pacing:

https://www.mathworks.com/help/releases/R2020a/simulink/ug/simulation-pacing.html