How to take values generated from a MATLAB program and display them in a Simulink block?

Question

I have a working MATLAB program hooked up to an Arduino and rotary sensor that displays the current angle. I would like to display this angle on a Simulink model, so I can control a motor based off the current angle. Is there any way to do this without creating an angle sensor in Simulink and just using my MATLAB code that already works?

Answer 1

Your question is not really clear and it depends if you are trying to do it before simulation or during simulation.

If you want to do it before the simulation, just create a constant block with a variable name that is taken from the workspace, and let your function to set that variable in the workspace.

If you want to do it during simulation, it is a little more difficult but still possible. Lets create a sample a MVCE. The simulink model mask.slx contains a constant the is set to 0, and this constant value is displayed in the display block on the right. The simulation time is set to inf, so when you play it, you must stop it manually.

It is possible to checge the value of the constant while the simulation is running using this simple Matlab call:

set_param('mask/Value_to_set', 'Value', '10')

you should also consider that the constanta must be a Tunable gain (it is by default).

(as you can see the simulation is running).

There are some additional (and surely better) solution you can use:

1. Include your Matlab function in a MATLAB User Defined Function block, and call it at each simulation iteration. If you have compilation issue you shall follow the coder.extrinsic way (here an example for fmincon)
2. Use the Simulink Support Package for Arduino Uno Hardware Add-on that is available in the Add on store.